Naked Science Forum

On the Lighter Side => Science Experiments => Topic started by: paul.fr on 07/03/2007 01:35:40

Title: What's your kitchen science?
Post by: paul.fr on 07/03/2007 01:35:40
not sure if this is the right section for this topic, but here goes.

We all love the kitchen science part of the show, but what are your favourite kitchen science experiments? Either those featured on the show / podcast, or ones you have done yourself?

Why not post them here, and let us all enjoy the wonder of experimentation.

Just post the items you need, and how to conduct the experiment. Like the kitchen science on the show, please do not post what the final result is. That way we will not lose some of the enjoyment of conducting the experiment.

If a member is unsure of his/her results they could always pm the poster.


OK, here is a simple on to start thins off. I have already posted this somewhere, and there was some doubt as to whether it worked. so why not try for yourself and then post one of your own:

What you need

2 cups
about 15 copper coins
salt
a nail
and vinegar

What you do

place your copper coins in your cup and cover them with salt. Then pour in some of your vinegar, to about 1cm above the top coin.

leave for half to one hour, then drain the solution in to the other cup. At this point you will have shiny copper coins, but that is not the whole experiment.

With just the solution in the second cup, drop your nail in to it and wait another half to one hour.

What happens to the nail?

topic link

Why does vinegar make copper coins all pink and shiny? http://www.thenakedscientists.com/forum/index.php?topic=6240.0
Title: Re: What's your kitchen science?
Post by: neilep on 07/03/2007 01:56:46
What a wonderful idea Paul.

I will try this experiment and let you know the results in due course.

C'mon everybody...YAYYYYYYYYY !!


I love doing the old playing with cornstarch thing.



What you need

Cornstarch
Bowl
Water
Sense of fun




What you do.


Pour a cup or two (or more) of cornstarch into a bowl and add water till it becomes  quite gloopy...add the water a little at a time !!


When all is done, settle it in the bowl and you can handle it very easily nice and slow...it's sticky and slimy !

But what happens when you apply a sharp smack to the solution with the back of a spoon or the palm of your hand ?

topic link

quicksand http://www.thenakedscientists.com/forum/index.php?topic=7379.0
a question for all you smart types http://www.thenakedscientists.com/forum/index.php?topic=4767.0
Title: Re: What's your kitchen science?
Post by: Karen W. on 07/03/2007 03:41:49
We call It gack at the preschool it is really cool to play in even for adults like me... Really I am not an adult just a big kid!
Title: Re: What's your kitchen science?
Post by: daveshorts on 07/03/2007 09:13:30
The copper one is cool, thanks paul, it might just end up on the show ;)
Title: Re: What's your kitchen science?
Post by: paul.fr on 07/03/2007 10:11:12
The copper one is cool, thanks paul, it might just end up on the show ;)

Thanks Dave.

On a previous podcast Chris was giving away a mud powered clock. Now i have no idea how that works, but it did remind me of another experiment.

What you need

A Lemon
A piece of copper wire, about 2 inches long
A paper clip
Yout Tongue

What you do

Push the piece of copper wire about half an inch in to one end of the lemon, then gently straighten out the paper clip and push it in to the lemon about one onch away from where you have stuck the copper wire.

Now stick you tongue on to both the free ends of the copper wire and the paper clip.

What happens?

topic link

Could we power cars and lorries with fruit-generated electricity? http://www.thenakedscientists.com/forum/index.php?topic=7344.0
Title: Re: What's your kitchen science?
Post by: neilep on 07/03/2007 16:24:14
Dem bones dem bone dem dry bones !!..laa dee daa dee daa !

What you Need

1 : Some well cleaned chicken bones with no stuff on them..just nice clean bones .

2: A week !

What You Do

Stick em in a jar and fill with white vinegar...leave for a week.
take em out...

What has happened to the bones ?

Title: Re: What's your kitchen science?
Post by: paul.fr on 08/03/2007 01:14:53
What you need

A fat/chunky felt tip pen
A woolen cloth or jumer
A plate
Salt and Papper


What you do

Sprinkle some salt an pepper on to the plate. Then get your woolen cloth or jumper and rub it very hard along your felt tip pen for about 1 minute.

stop rubbing, discard the cloth/jumper and move the pen slowly over the plate.

What happens?
Title: Re: What's your kitchen science?
Post by: Karen W. on 10/03/2007 04:06:56
MY Guess depending on "What kind of a plate,ie paper plastic or glass, on corelle or other metalic plate," I expect to see static electricity, but that depends on the plate So tell me what Kind of plate so I can do this??

Wait a moment I just thought of something. It may just act like a magnet eh... Hummmmm I have to go try it!LOL Driving me crazy!
Title: Re: What's your kitchen science?
Post by: paul.fr on 10/03/2007 13:46:48
MY Guess depending on "What kind of a plate,ie paper plastic or glass, on corelle or other metalic plate," I expect to see static electricity, but that depends on the plate So tell me what Kind of plate so I can do this??

Hi Karen,

just an ordinary dinner or side plate will do.
Title: Re: What's your kitchen science?
Post by: paul.fr on 10/03/2007 14:16:33
What you need

A balloon
Your head
The kitchen sink!


What you do

Firstly, blow up the balloon. Then turn your cold tap on..just a little so you get a nice staedy thin stream of water going into the sink.

Then rub the balloon on your head or a wooly jumper for a minute or two.

now slowly move the balloon closer to the stream of water..but don't get too close as to wet your ballooon.

What happens to the water?
Title: Re: What's your kitchen science?
Post by: paul.fr on 10/03/2007 17:27:22
Strictly for adults only

What you need


An empty cola can
A cooker/stove
Oven gloves
Water
Your kitchen sink


What you do

First, fill your sink with cold water. Then after drinking the cola fill the can with cold water and heat in on your cooker/stove.

When the water in the can is boiling, using your oven gloves, take the can and turn it upside down allowing the water to escape and put it in the cold water in your sink.

What happens?

Try repeating the experiment, with a fresh can, this time keeping most of the hot water in the can.

What if anything do you notice different to the first time?
Title: Re: What's your kitchen science?
Post by: Karen W. on 10/03/2007 18:41:52
What you need

A balloon
Your head
The kitchen sink!


What you do

Firstly, blow up the balloon. Then turn your cold tap on..just a little so you get a nice staedy thin stream of water going into the sink.

Then rub the balloon on your head or a wooly jumper for a minute or two.

now slowly move the balloon closer to the stream of water..but don't get too close as to wet your ballooon.

What happens to the water?
Perhaps it will become charged with electricity.. Have to try this one too!
Title: Re: What's your kitchen science?
Post by: paul.fr on 10/03/2007 18:47:31

Perhaps it will become charged with electricity.. Have to try this one too!

Karen, make sure the mater is a slow steady continuous stream. not a fast flow of water, as you move the "charged " balloon closer to the stream of water watch the water not the balloon.
Title: Re: What's your kitchen science?
Post by: neilep on 10/03/2007 19:06:27
Magic Crystals !!

This is fun way to make crystal formations.

What You Need.

2 tbsp epsom salts
 1/2 cup water

What You Do.

Line a flat dish or the lid from a large jar with black Sugar paper (construction paper) squishing it securely onto the bottom. Dissolve the epsom salts in the water and pour a thin layer of this solution into the paper-lined dish. Now, leave it alone to allow the water to evaporate, undisturbed. This might take a day or so, depending on temperature and humidity. There should now be a beautiful formation of crystals visible on the paper.

Brilliant !!
Title: Re: What's your kitchen science?
Post by: Karen W. on 10/03/2007 19:16:59
Cool My kiddos will love that one!!! YAYYYY These will be cool at school Thanks Paul and Neil... YAYYYYYYYY!!!
Title: Re: What's your kitchen science?
Post by: paul.fr on 11/03/2007 17:15:35
Here is one you can eat afterwards.....yummy.


What you need

carbonated soda, i prefer ice cream soda...
ice cream
two glasses


What you do

Put a scoop of ice cream into one glass. Pour some of the soda into the other.

now add some soda to the glass with the ice cream. Try to add the same amount of soda that you put into the other glass.
 
What happens?

Next, add a scoop of ice cream to the glass with the soda.

What happens this time?

once finished you can eat the contents of your glasses....lovely
Title: Re: What's your kitchen science?
Post by: paul.fr on 12/03/2007 09:38:33
Ever wondered, or been asked how a thermos flask works?

Ok, this is not so much an experiment, as a how to make...but you can use it to experiment with!

What you need

Two clear jars with screw on lids, one big enough for the other to sit inside.
A cork
Kitchen foil
Sticky tape


What you do

Wrap and tape securely two layers of the kitchen foli around the smaller jar, with the shiny side facing inwards. Pour some warm water in to the jar and screw the lid on.

Put the cork in the bottom of the larger jar, and stand the smaller jar on top of it and screw the lid on. You now have your own home made thermos flask.


Your turn Neil  [;D], come on Karen, you must have something to contribute. No matter how big or small, let us in on the things you do with the kiddies.
Title: Re: What's your kitchen science?
Post by: paul.fr on 15/03/2007 09:56:39
Clouds


What you need

a clear two liter drink bottle with its lid
water
paper
a match or lighter


What you do

Remove the label/s from the bottle.

Standing the empty bottle upright, put about 1 inch of water in it. Screw the lid on and give it a good shake.

Cut a long thin strip of paper. thin enough so that it easily fits into the mouth of the bottle. Remove the lid from the bottleand carefully use the match or lighter to set the end of the paper strip on fire.

Give it a second to burn and then blow out the flame. When it is out you will see smoke rising from the burned paper.

Quickly stick the end of the paper into the bottle, so that a little smoke gets inside. Remove the paper and screw the lid on to the bottle.

Quickly out the burning paper and  squeeze the bottle very hard and quickly release it.

What do you see?

Now squeeze the bottle hard again, this time squeeze and release a couple of times in quick sucsesion.

Now what do you see

Repeat the squeezing and releasing until you get bored!

Title: Re: What's your kitchen science?
Post by: ROBERT on 19/03/2007 15:09:29
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi24.photobucket.com%2Falbums%2Fc23%2FSUEDONIM%2Fcoffeemystery.jpg&hash=df7f3ebb6c6cf38a8cf840d88722c4a0)

If you place a cup of black coffee close to your washing machine
while it is spin-drying you will see a series of patterns like this one.

Use cold coffee to avoid burns.
Only fill the cup 2/3rds full, not to the brim as shown here, to avoid spillage.
You may need to hold the cup down, or fix it with blue-tak, to stop it moving.
Title: Re: What's your kitchen science?
Post by: paul.fr on 21/03/2007 18:35:29
Nice pretty patterns, thanks Robert.

here is one for you to do with the kiddies at school, Karen.

Pretty mushroom pictures

What you need

A large mushroom
A black piece of card, bigger than the mushroom
A bowl, big enough to span the mushroom

What you do

Cut off the stalk, and put the mushroom face down on the centre of the card. Cover with the bowl and leave for a few days.
Note: some mushroon spores are not white, so you may need to use a different coloured piece of card depending on the colour of your mushrrom spores.
Title: Re: What's your kitchen science?
Post by: paul.fr on 21/03/2007 18:54:33
What you need

some water that has been cooled for a few hours.
hot water
food colouring
a glass or glass jar


What you do

Half fill the glass with hot water, add a few drops of food colouring and give it a good stir. Now add the cold water.

What happens?
Title: Re: What's your kitchen science?
Post by: Karen W. on 22/03/2007 07:39:48
Cool I will try them with the children they can each do their own picture print with the mushrooms. Nice!!
Title: Re: What's your kitchen science?
Post by: paul.fr on 22/03/2007 09:51:42
Here is the one you aked for, Karen.

What you need


Hot water
baking soda
Aluminium foil
a bowl
silver cutlery


What you do

Put a cup full of baking soda in to the bowl, and add six cups of hot water. Stir until tyhe baking soda is disolved, then add strips of the aluminium foil.

Put the cutlery in to the bowl, after a few minutes remove the silver cutlery and give it a good rinse. then a nice little polish.
Title: Re: What's your kitchen science?
Post by: paul.fr on 22/03/2007 20:16:42
What you need

a dark room
a stsndard "white" light bulb
a red light bulb
any other coloured bulbs you have or can get
a white wall or large sheet of white paper
two lamps
the bulbs should be the same wattage.


What you do


First, shine the white light onto the white wall. Put your hand in between the light and the wall and look carefully at the shadow. See if you can make a shadow that looks like a bird, or whatever shadow shpe you can make. The shadows look normal, dark areas on the white wall.

Turn off the white light and turn on the red one. Try making shadow pictures again. It works pretty much the same, except that now the wall looks red instead of white. The shadows are still dark. With the two lights about a foot apart, turn on both lights. With both lights shining on the wall, it will probably look white. The white light tends to overpower the red. Place your hand to make a shadow again.


you now have two two shadows, one from each light. One shadow will be red. The other shadow is ?

If you managed to get hold of different coloured light bulbs, replace the red bulb with your different coloured bulb. what do you see now?


If you do not have two lams, you could always use two torces. Just make sure the are on "flood" and not a concentrated "spot", you can easily make coloured filters for your torch.



The following information is supplied by George, another_someone, and may help you if you want to make filter for your lamp if you can not find different coloured bulbs.

Probably the simplest improvised filters you can produce for lighting would be coloured acetate sheets (but they are likely to be very uncalibrated in their colour, and you will have to make sure they do not get too hot).

Another option for creating colour is not to use direct filters that allow transmitted light of a given colour, but to use coloured reflectors that reflect the colour you want onto the subject (you will have to make sure that you block off any direct light between the source and the subject, and that the subject is only illuminated by reflected light).
Title: Re: What's your kitchen science?
Post by: Karen W. on 23/03/2007 02:45:54
COOL THANKS PAUL! I AM GOING TO TRY THEM!!!! SOUNDS FUN< THE KIDS WOULD LOVE THE SHADOW ONE> WE DID A SHEET WITH ALL THE LIGHTS OFF AND LET THEM MAKE SHADOWS> THIS COULD BE REALLY COOL IF WE PLAN IT RIGHT! THANK YOU THANK YOU THANKYOU!!!! FUNNNN!!!!YAYYYYYYYYYYYY!!!!!!!!
Title: Re: What's your kitchen science?
Post by: neilep on 23/03/2007 14:45:49
What you need.

A few Eggs , Strawberries (or any other soft fruit)
A mallet


What you do


Place the eggs and fruit on the kitchen table
making sure all are around to view the results.

Apply a sharp thwack to the eggs and fruit.


What happens ?


Title: Re: What's your kitchen science?
Post by: Karen W. on 23/03/2007 15:51:49
LOL... I can imagine The looks on your childrens faces as you perform this experiment!! LOL
Title: Re: What's your kitchen science?
Post by: paul.fr on 23/03/2007 22:43:11
What you need


Lemon juice
cotton bud/s
absorbant paper/kitchen roll
an iron


What you do

Dip the cotton bud in to the lemon juice and make some pretty picture or just writing on the paper/kitchen roll. when finished leave your paper/kitchen roll to fully dry for 10 to 15 minutes.

You don't want to soak the paper/roll.

Now run your hot iron over the paper/kitchen roll.

What happens?


you can try it with other things, such as cabbage juice
Title: Re: What's your kitchen science?
Post by: paul.fr on 24/03/2007 08:03:48
Are you hot enough!


What you need

Tap water
Rubbing alcohol
Clear, narrow-necked plastic bottle
Food colouring
Clear plastic drinking straw
Modeling clay


What you do

Pour equal parts of tap water and rubbing alcohol into the bottle, filling about a quater hight.

Add a couple of drops of food colouring and mix.Put the straw in the bottle, but don't let the straw touch the bottom.

Use the modeling clay to seal the neck of the bottle, so the straw stays in place and hold your hands around the bottle.

What happens?

Warning: Do not drink the contents of the bottle, supervise any children.
Title: Re: What's your kitchen science?
Post by: paul.fr on 25/03/2007 00:01:02
Electrolosis

What you need


A 9 volt battery
Two pencils
Salt
Thin cardboard
Electrical wire
Small glass
Water


What you do


Sharpen each pencil at both ends.
Cut the cardboard to fit over glass.
Push the two pencils into the cardboard, about an inch apart.
   
Dissolve about a teaspoon of salt into the warm water and let sit for a while.

Using one piece of the electrical wire, connect one end on the positive side of the battery and the other to the lead at the top of the sharpened pencil. Do the same for the negative side connecting it to the second pencil top.

Place the other two ends of the pencil into the salted water.

What do you see, and why?
 
Title: Re: What's your kitchen science?
Post by: mhorton on 26/03/2007 07:27:59
What you need:

Plastic overhead transparency sheet (acetates)
Scissors
Dishwashing liquid
Bowl of water

Cut the transparency sheet into small boats with a channel coming out of the rear of the boat.

Float the plastic boat in a bowl of water and let it set until the water is still.

Place a single drop of liquid soap in the channel of the boat.

What happens?

Very cool.  There are several very reasonable explanations for this, but the most common involves surface tension.
Title: Re: What's your kitchen science?
Post by: mhorton on 26/03/2007 07:33:34
What you need:

A roll of transparent tape
A dark room (optional)

Peel off a piece of transparent tape approximately 4 cm long and hand it to an assistant.

Peel off another piece of transparent tape approsimately 4 cm long.

Bring the two pieces of tape near each other.  What happens?

Stick a 4 cm piece of tape flat onto the surface of a table.  Fold over the end so that you can lift it off the table later.

Stick another 4 cm piece of tape on top of the first.  Fold over the end so that it can be lifted up.

Quickly lift the top piece of tape and hand it to an assistant.

Quickly lift the bottom piece of tape.

Bring the pieces of tape near each other.  What happens?

In a dark room after your eyes have adjusted to the darkness, quickly pull some transparent tape off of the roll.  What happens?

Hints: Static electricity, unlikes attract, likes repel.
Title: Re: What's your kitchen science?
Post by: daveshorts on 26/03/2007 11:22:47
Be careful when electrolysing salt, as you will generate chlorine, which whilst will probably mostly dissolve, was used as a chemical weapon...
Title: Re: What's your kitchen science?
Post by: paul.fr on 27/03/2007 06:03:49
following on from the experiment posted by mhorton, a similar one was done on the naked science show using a matchstick. Here is another variation.


What you need

a bowl
milk
3 or more different food colourings
liquid soap/washing-up liquid
a toothpick


What you do

pour some milk in your bowl, and put some of the food colouring in the milk.

take your toothpick and dip it in the liquid soap/washing up liquid, then dap the toothpick in the centre of the bowl

topic link

Surface Tension !..what is it ? http://www.thenakedscientists.com/forum/index.php?topic=4710.0
Title: Re: What's your kitchen science?
Post by: Karen W. on 28/03/2007 10:06:40
CD LOVE

1 new blank CD
1 microwave
five seconds on the microwave insert cd into microwave close door! LOL
Press start and watch closely!

when microwave stops remove cd and examine...

BTW It did not damage my Microwave!
Title: Re: What's your kitchen science?
Post by: paul.fr on 28/03/2007 20:33:47
Three for the price of one!


What you need

three eggs.
five glasses
vinegar
corn syrup
water
3 days!


What you do

Put the three eggs in to the seperate glasses, and fill the glass with vinegar. Wait two or three days!

What do you notice?.....the egg has no shell!  Why?

Experiment one

Take one of your eggs, feels strange. now try dropping it from a few inches high on to your work surface, what happens? repeat with increasing height until you, A, get bored or B have a smashed egg.

Experiment Two

Take one of the other eggs and put it in an empty glass, fill the glass with water. What happens?

Experiment three

Take the last egg. put it in your remaining empty glass and fill with corn syrup. what happens?
Title: Re: What's your kitchen science?
Post by: paul.fr on 28/03/2007 22:08:58
What you need

a candle
matches or a lighter
several balloons
water


What you do

Blow up one of the balloons and tie it off. Light the candle.  Carefully, hold the balloon just at the top of the candle
flame.

What happens? you guessed it, the balloon burst.

Carefully stretch the mouth of the other balloon over a tap( american: water faucet) and slowly fill the balloon with water. Then blow in a little air and tie it off.

Once again, light the candle, and hold the balloon over the candle, just at the top of the flame.

What happens this time?


Please use caution when using candles
Title: Re: What's your kitchen science?
Post by: paul.fr on 28/03/2007 22:19:59
What you need

Glass bottle. One with a short neck works best.
A medium-sized balloon with the neck of the balloon cut off just below the opening
A large bowl
Water



What you do

Fill the glass bottle with warm-to-hot water and Let it sit for about 3 minutes so the bottle warms up. Then Pour cold water into the bowl until it’s about 3/4 full.

empty the warm water out of the bottleand Stretch the balloon over the top of the bottle.
Put the bottle into the bowl of water.

What happens?
Title: Re: What's your kitchen science?
Post by: WylieE on 29/03/2007 02:17:19
What you need:
A rubber band- a good thick one works better, but any one will do

What to do:
Hold the rubber band with both hands.
Put it up to your lips or forehead and feel the temperature.
Now stretch it out.  Now quickly put it up to your lips or forehead again- is there a change in temperature?  Now let it relax and check the temperature again. 

What's going on?
Check out this thread:
http://www.thenakedscientists.com/forum/index.php?topic=6955.0

Colleen
Title: Re: What's your kitchen science?
Post by: paul.fr on 31/03/2007 11:54:15
What you need

Soda water/fizzy water
empty bottle or glass
rasins

What you do

Fill the glass or bottle half full with soda water. Drop three or four raisins into the water.
wait a while.

what happens?
Title: Re: What's your kitchen science?
Post by: paul.fr on 31/03/2007 11:58:51
an old favourite

What you need

A narrow necked glass bottle
3 matches
a peeled, hard bolied egg

What you do

Drop three lit matches into the glass bottle. Quickly put the hard-boiled egg on the mouth of the bottle.

What happens?
Title: Re: What's your kitchen science?
Post by: Karen W. on 31/03/2007 17:49:08
HEE HEE HEE! That one is also my favorite, I have a question about the results of this one. I have done it several times..and each time am at a loss for retrieving my lunch from the bottle, LOL Can one reverse the process Paul? LOL
Title: Re: What's your kitchen science?
Post by: Karen W. on 31/03/2007 17:52:46
I also have a question if one pierced an egg before cooking and did this same experiment, would the suction be strong enough to pull the yolk from the shell leaving the shell whole. You know like when you blow the contents out?
Title: Re: What's your kitchen science?
Post by: paul.fr on 31/03/2007 17:58:16
May be i should have included that  [:I]

Turn the the bottle upside-down, Put the bottle over the top of your head, like you are leaning you head back and looking up at the bottle.

Wit the bottle about half and inch from your mouth, blow into the bottle hard, and don't stop. The egg should come out.

or you can heat the bottle under warm water and the egg will come out.
Title: Re: What's your kitchen science?
Post by: paul.fr on 31/03/2007 18:27:26
I also have a question if one pierced an egg before cooking and did this same experiment, would the suction be strong enough to pull the yolk from the shell leaving the shell whole. You know like when you blow the contents out?

I like that, give it a try and let me know would you?
Title: Re: What's your kitchen science?
Post by: Karen W. on 31/03/2007 18:48:27
May be i should have included that  [:I]

Turn the the bottle upside-down, Put the bottle over the top of your head, like you are leaning you head back and looking up at the bottle.

Wit the bottle about half and inch from your mouth, blow into the bottle hard, and don't stop. The egg should come out.

or you can heat the bottle under warm water and the egg will come out.


LOL LOL.. HEE HEE HEE!!  I don't know if I have enough air to continuely blow like that, BUT Paul, I think you should try it, but shouldn't you be "SUCKING" instead of blowing??? Will the egg really come out if you are blowing! LOL

So you never tried the other one.. HUMMMMM I will have to try it out and see!!!
Title: Re: What's your kitchen science?
Post by: paul.fr on 31/03/2007 19:07:15

shouldn't you be "SUCKING" instead of blowing??? ! LOL


No, it's all to do with air pressure. If you don't have the lungs for blowing you could always use a hairdryer. or, add about an inch of water to the bottle and break up an alka seltzer tablet/bicarbonate of soda . Put the tablet in the bottle then turn the bottle upside down. The pressure from the expanding gas should blow the egg out of the bottle.
Title: Re: What's your kitchen science?
Post by: Karen W. on 31/03/2007 19:18:20
 OH that is interesting, I guess me brain doesn't work like that, cause that never occured to me. HMMMMM I will try it next time!

I could try the hair dryer that might do it! we will see!
Title: Re: What's your kitchen science?
Post by: paul.fr on 01/04/2007 23:58:57
Found this one on the net. similar to one done by Dave


What you need

water
a squirt of dishwashing liquid
1/2 a teaspoon of salt
1 teaspoon of ice cold ethanol or methylated spirits or rubbing alcohol (isopropanol)
two cups and
a clear container with a lid


What you do

1.Dissolve half a teaspoon of salt in half a cup of water. Add a squirt of dishwashing liquid. This liquid will be used to break up the cells and release the DNA.

2.Take about a tablespoon (20 - 25 mls) of plain water into your mouth. Don't swallow! Swish the water around your cheeks vigorously for about 30 seconds. This removes some cheek cells. Spit the water into a clean cup or glass.

3.Add about 1 teaspoon (5 mls) of this fluid to a small clean container with a lid (a 20 ml test-tube or a clear plastic film canister would work). Add about half a teaspoon (2.5 mls) of the salt/dishwashing liquid (saline/detergent) solution. Put the cap on the container and tip it up and down gently 3 or 4 times to mix (but you don't want a lot of froth so don't shake it). This will break up the many hundreds of cheek cells, releasing the DNA from the nucleus.

4.Gently run a teaspoonful of ice-cold ethanol into the tube. Methanol or rubbing alcohol - isopropanol - should also work; make sure they are ice cold by placing the bottle in the freezer for a few hours before the experiment. Watch the point where the two layers meet. You may see strands of DNA forming, as cloudy filaments stretching up into the top (ethanol) layer. DNA is not soluble in ethanol, so when the ethanol meets the DNA solution it starts to precipitate (form a DNA salt).

5.You may be able to hook out the strands of DNA with a glass hook (or one made from a plastic twist-tie) by slowly dipping up and down through the two layers. If this doesn't work, gently invert the tube several times until the alcohol is mixed in. The precipitated DNA will look like a small ball of white thread.

topic link

HOW IS DNA SEPARATED FOR DNA FINGERPRINTING? http://www.thenakedscientists.com/forum/index.php?topic=5889.0
An excellent experiment by Daveshorts (Dave Ansell) http://www.chaosscience.org.uk/pub/public_html//article.php?story=20050524184709373
Title: Re: What's your kitchen science?
Post by: paul.fr on 02/04/2007 00:36:11
An easy one, to confuse the kids with.

What you need

A small apple or orange
a piece of paper


What you do

Hold the apple/orange and the paper at the same height from the ground and drop them at the same time.

Which hits the ground first? yes the apple/orange

Now scrunch the paper into a round ball the same size as the apple/orasnge and repeat dropping them from the same height.

Which hit the ground first this time?
Title: Re: What's your kitchen science?
Post by: daveshorts on 02/04/2007 11:52:05
The above procedure will extract both DNA and proteins, so the gunk you see may not be all DNA, to get more pure DNA you need to break down the proteins. To do this you need an enzyme called a protease. fresh pineapple and kiwi juices have these, which is why they hurt to eat - they are digesting your mouth. So you could add these and keep the mixture warm for 10mins or you could just extract teh DNA from kiwi fruit.

Here is something I wrote a while back about this which you may find interesting
http://www.chaosscience.org.uk/pub/public_html//article.php?story=20050524184709373
Title: Re: What's your kitchen science?
Post by: Karen W. on 03/04/2007 03:59:06
Thanks Dave and Paul I am excited to try this one.. I have never done this before.. Me is very happy!!!!! YAYYYYYYYY!! I want to see DNA!!! YAYYYYYY!
Title: Re: What's your kitchen science?
Post by: paul.fr on 03/04/2007 10:20:08
I would not do that DNA one first, Karen. I would do Dave's kiwi fruit one then the other. Dave's is much better, i thought dave had it in the kitchen science section of the main site but can't find it!

so here is a link to the kiwi fruit one on daves own site: http://www.chaosscience.org.uk/pub/public_html//article.php?story=20040206021823942

Which is also well worth looking around.
Title: Re: What's your kitchen science?
Post by: paul.fr on 03/04/2007 10:25:09
The above procedure will extract both DNA and proteins, so the gunk you see may not be all DNA, to get more pure DNA you need to break down the proteins. To do this you need an enzyme called a protease. fresh pineapple and kiwi juices have these, which is why they hurt to eat - they are digesting your mouth. So you could add these and keep the mixture warm for 10mins or you could just extract teh DNA from kiwi fruit.

Here is something I wrote a while back about this which you may find interesting
http://www.chaosscience.org.uk/pub/public_html//article.php?story=20050524184709373

thanks for that, Dave. Just out of curisity, will you be adding any more dates to the chaos tour/roadshow?
Title: Re: What's your kitchen science?
Post by: Karen W. on 03/04/2007 16:48:58
 I will try both!! Thanks!
Title: Re: What's your kitchen science?
Post by: daveshorts on 03/04/2007 19:51:07
thanks for that, Dave. Just out of curisity, will you be adding any more dates to the chaos tour/roadshow?

We are attempting to finalise the tour's dates fairly soon, if we raise enough money. The plan is to go to Devon, Dorset, bits of Suffolk Gloucester, amongst others.

Do you have anywhere you would want us to go?
Title: Re: What's your kitchen science?
Post by: paul.fr on 03/04/2007 21:54:28
What you need

A microwave
3 grapes


What you do

take one grape, with it's stem/stalk attached and put it in the microwave for 10 seconds. What happens?

OK, that was fun, but this next one is just....cool.

take the remaining two grapes, and remove the stem/stalk. place them in the microwave with the hole where the stem/stalk was facing eachother. they should be about half a centimeter apart.

now cook them for 8 to 10 seconds, but no longer than that. if you repeat this use fresh grapes.

What happens?


do not cook the grapes for longer than 10 seconds, cooking for longer has a slight chance of damaging your microwave.
please also note that the grapes will be very hot and inedible
Title: Re: What's your kitchen science?
Post by: paul.fr on 04/04/2007 21:59:57
What you need

a jar with a lid
a thermometer
steel/wire wool
vinegar
a bowl

What you do

put the therrthermometer into the jar and put on the lid. Let the jar sit for about 15 minutes and then check the temperature.

Next, place the steel wool into a small bowl. Pour some vinegar onto it,  using enough to get the steel wool very wet. Squish it around a bit and then squeeze out as much vinegar as you can.
Put the wet steel wool into the jar, up against the thermometer. Again, note the temperature. Put the top on the jar and leave it for five minutes.

After five minutes, check the temperature again. What do you notice?
 
Put the lid back on the jar and wait another 10 minutes. Check the temperature again. Then wait another 10 minutes and check again.

What is happening to the temperature?
What has happened to teh steel wool?
Title: Re: What's your kitchen science?
Post by: paul.fr on 09/04/2007 09:42:39
What you need

an egg
a tall glass
salt
water


What you do

half fill the glass with water, then add enough salt to saturate the water, 4 to 6 spoonfulls should do. wait a minute or two

then carefully fill the glass with more water, pouring gently down the side of the glass is best as you do not want the two layers of water to mix.

gently put the egg in to the top of the glass and let go.

what happens?
Title: Re: What's your kitchen science?
Post by: paul.fr on 09/04/2007 10:11:47
kids love science and ice cream so why not do both! Sure most of us will have done this before but i thought it worth posting anyway.

What you need

ice cubes
salt
one large glass bowl
one smaller glass bowl
tea towel
double cream (from memory i think it's double cream)
milk


what you do

mix a tablespoon of cream with two of milk in the small bowl. put a lyer of ice cubes in the large bowl and sprinkle salt over the ice cubes.

put the small bowl in the middle of the large bown and pack more layers of salt ice cubes around it until the ice is as high as the bowl.

cover the bowls with the tea towel and leave for one hour, stirring every five minutes. you can add cocoa powder at the initial stage for chocolate ice cream.

one hour later, eat the ice cream

if you bowls are quite large them obviously you can double up the quantities of cream and milk to make more ice cream.

can someone let me know if i am right about the double cream as i will be making some at the weekend. thanks in advance.
Title: Re: What's your kitchen science?
Post by: Karen W. on 10/04/2007 03:16:14
Yummm!
Title: Re: What's your kitchen science?
Post by: paul.fr on 11/04/2007 19:56:53
summer is coming and we may be having a bar-b-que, well this is not so much an experiment as a how to.

cook eggs on a barbque

what you need

a barbque
plastic carrier bag
water
eggs


what you do

wait until the barbque is over, spread the hot ashes/coales on the floor. the ashes must be hot and not flaming.
fill your carrier bag with water and add the eggs
hold the carrier bag on top of the hot ashes/coles and the water will boil and cook your eggs

the science angle here is why the plastic bag does not melt!
Title: Re: What's your kitchen science?
Post by: neilep on 12/04/2007 00:24:38
Self-Inflating Balloon
This is a really slow way to blow up a bunch of balloons for your birthday party but at least you won’t get out of breath.

WHAT YOU NEED:

1 tsp active dry yeast (5mL)
1/4 cup sugar (50 mL)
1 cup warm water (250 mL)
1 balloon

WHAT YOU DO :

In a 1-litre (1 quart) bottle (like a pop bottle) combine the sugar, the yeast and the warm (not hot) water. Hold your hand over the opening and shake to mix well. Blow up the balloon once or twice to pre-stretch it, then put it over the opening in the bottle, and tie it on securely with string or tape. Set the bottle into a bowl filled with very warm water, and go away for about an hour. When you return, the balloon will be partly inflated. Leave it alone and see how big it gets.

Title: Re: What's your kitchen science?
Post by: Seany on 12/04/2007 17:20:26
What you need

A Film Canister
Baking Powder
Vinegar

What to do

Put a fair amount of baking powder into the film canister

Put a fair amount of vinegar in, and put the lid on the container real fast!

Stand back about 5 metres.

What happens?
Title: Re: What's your kitchen science?
Post by: paul.fr on 12/04/2007 17:39:42
nice one sean. by film container you mean the little container to take your camera film to be processed in. just in case anyone was wondering.
Title: Re: What's your kitchen science?
Post by: Seany on 12/04/2007 17:42:30
Yah, I don't know what they're called..

EDIT: Oh its called a film canister!
Title: Re: What's your kitchen science?
Post by: paul.fr on 13/04/2007 18:24:04
what you need

2-liter plastic soda bottle
a ten pence piece, or whatever coinage you use that is the size of the bottle top
Water


what you do


Place the empty uncapped bottle in the freezer for 10 minutes. Dip the coin in water.

Remove the bottle from the freezer and immediately place the wet coin on the top of the open bottle.

what happens?

Title: Re: What's your kitchen science?
Post by: Seany on 13/04/2007 21:06:24
Hmm.. I'm not sure of that experiment. At the beginning, is the coin bigger (cannot go in the hole), equal to (still cannot go in the hole) or smaller than the hole (can go in the hole)?
Title: Re: What's your kitchen science?
Post by: paul.fr on 13/04/2007 21:31:15
Hmm.. I'm not sure of that experiment. At the beginning, is the coin bigger (cannot go in the hole), equal to (still cannot go in the hole) or smaller than the hole (can go in the hole)?

you need a coin the same size as the mouth of the bottle, so its sits nicely on the "hole"  [;D] does not hang over or fall in.
Title: Re: What's your kitchen science?
Post by: Seany on 13/04/2007 21:55:56
Ohh! Ok. And great, your on 1000 posts [;D] Just couldn't help realising. [:P]

Ok.. So the outcome of the result would be.... Ugh I'm not sure!?

Putting the bottle in a freezer, would make the hole that little bit smaller, and then putting a "wet" coin would.. Oh I'm stuck! Oh well, I bet either way the result is that the coin falls into the hole. But I'm not sure why..
Title: Re: What's your kitchen science?
Post by: paul.fr on 13/04/2007 21:58:06
Putting the bottle in a freezer, would make the hole that little bit smaller, and then putting a "wet" coin would.. Oh I'm stuck! Oh well, I bet either way the result is that the coin falls into the hole. But I'm not sure why..

you have to try it to find out...oh and your conclusion is wrong  [B)]
Title: Re: What's your kitchen science?
Post by: Seany on 13/04/2007 21:59:27
Oh.. Does the coin just miraculously POP and fly out? [:P]

Well.. I'm once again lazy to do this experiment. [:D] Will look on the web! [:P]
Title: Re: What's your kitchen science?
Post by: Seany on 13/04/2007 22:00:44
Ohh wait! I've read this in a book somewhere!!! This is the one where the coin tilts slightly.. and then goes down.. then goes up slightly.. then goes down.. and it makes a noise.. right?
Title: Re: What's your kitchen science?
Post by: Seany on 13/04/2007 22:03:10
Ah, I've just found it on the internet. But I'm confused about one thing..

"When removed from the freezer, the cold air inside the bottle expands and tries to rush out of the bottle. This air flow causes the coin to move!"

Why does the coin need to be wet?
Title: Re: What's your kitchen science?
Post by: Seany on 13/04/2007 22:06:38
Spikes on a String

What you'll need

2 plastic cups
6 teaspoons of baking soda
1 foot length of string
4 cups of water
Spoon

Method

1. Fill each cup with 2 cups of water.

2. Put 3 teaspoons of baking soda in each cup and stir carefully.

3. Put one end of the string in each cup and let it sit for 1-2 days.


Soon, you will see the little spikes on the string. The water travels through the string and brings some of the baking soda with it, which creates the spikes.
Title: Re: What's your kitchen science?
Post by: paul.fr on 14/04/2007 23:20:06
in honour of Anastasia, George and Karen...............and sean

what you need

2 tin cans
some string
a friend


what you do

poke a hole in the bottom of both tin cans, thread your string through both holes and tie them off.

you should now a tin can connected to each end of the string, with the string stretched tight have your friend hold the can to his/her ear, whilst you talk in to the other can.

what happens?

topic link

phone wires http://www.thenakedscientists.com/forum/index.php?topic=7253.0
Title: Re: What's your kitchen science?
Post by: paul.fr on 14/04/2007 23:31:18
does bottled water taste better than tap water?

what you need

2 friends
2 cups
bottled water
tap water
stickers and a pen.


what you do

you need to create a double blind test. go to the kitchen and fill one glass with tap water and label it "a", and the other with bottled water and label it "b".

call your first friend in and ask him to take the glasses to your second friend, do not tell this friend what is in glasses and and b.

have the second friend try both glasses and tell you which he/she preferred.

try this with more than one friend actually sampling the two glasses to get a broader result. what was the outcome? which was the most preferred tap or bottled?

OK, one slight problem with this. normally between drinking samples of liquid, wine tasting for example you would swill your mouth with water so as not to taint the next glass but that is hard to do when water is the sample.

perhaps you could try running the experiment a second time, this time giving glass b first. then comparing your results.

topic link

hard or soft water http://www.thenakedscientists.com/forum/index.php?topic=7187.0
Title: Re: What's your kitchen science?
Post by: neilep on 14/04/2007 23:48:02
Candy Chromatography

What You Need :



    samples of candy such as m&m's, Skittles,
    set food colors for comparison
    filter paper--or coffee filters cut into 8 cm x 8 cm squares
    0.1% salt solution (1/8 tsp salt in 3 cups water)
    clear plastic 9 oz cups
    blow dryer
    toothpicks
    small (1 oz) plastic cups

What You Do :

Put 4 sweets (m&m's, Skittles,) of the same color in a small cup.
Add 5 or 6 drops of water.
When the white color of the candy comes through, remove and discard the candy.
Add 4 more sweets of the same color. Do not add more water!
Again, remove the sweets when the white coating is visible.
Repeat with 3 more colors.
Spot on coffee filter paper; use a hair dryer to dry the paper.
Develop in 0.1% salt solution
Title: Re: What's your kitchen science?
Post by: Karen W. on 15/04/2007 05:23:08
in honour of Anastasia, George and Karen...............and sean

what you need

2 tin cans
some string
a friend


what you do

poke a hole in the bottom of both tin cans, thread your string through both holes and tie them off.

you should now a tin can connected to each end of the string, with the string stretched tight have your friend hold the can to his/her ear, whilst you talk in to the other can.

what happens?

I have done this one many times we had a can phone tied in the top of my friends tree house in in the redwood forest and the string went swoopng down through the trees to her brothers bedroom windows and when we had to come in for dinner, her mom or brothers would pull the string and we would pick up the can and could here them telling us to come to dinner..LOLThe sound would vibrate down the string at least that is how it sounded like it worked,... like an extention to the vocal cords! It was very cool!
Title: Re: What's your kitchen science?
Post by: Seany on 15/04/2007 11:41:43
Yep. How far do you think the range is? Like the string.. How far could it go, until we couldn't hear anything in the cup?
Title: Re: What's your kitchen science?
Post by: that mad man on 15/04/2007 15:49:07
Freezing wine.

What you need:

1 x empty 300ml plastic drinks bottle.
1 x 100ml red wine.
A home freezer.


What to do:

Pour wine into empty bottle, seal with cap and then place upright in a freezer for 24hours.

After 24 hours take bottle from freezer using a towel and lay it on its side.

Questions:

What has happened?

Why does some of the wine still remain liquid?

Has this any practical use?

TMM



Title: Re: What's your kitchen science?
Post by: paul.fr on 18/04/2007 14:21:04
what you need


a two liter soft drink bottle or similar plastic bottle with a tight fitting
the bottle lid
refrigerator
hot water
a bowl of water
sink


what you do


remove the lid from the bottle. Place the bottle into the sink and run hot water over the outside of the bottle. After a few seconds quickly put the lid on the bottle. Be sure the lid is nice and tight.

Then place the bottle into the freezer compartment of your refrigerator.After couple of minutes, open the freezer and look at the bottle. What
happened to it?

Turn the bottle upside down in the bowl of water, so that the lid is under the surface. Remove the lid and the water rushes into the bottle.

You may have to squeeze the bottle a bit to get it back into its original shape. Leave the lid off and put it back into the freezer. Let it stay there for about 10 minutes. Then open the freezer and quickly put the lid on. Bring the bottle out of the freezer and squeeze it a bit to get an idea of the pressure inside.

Run some hot water over the bottle and squeeze it again. It feels more firm. Again put the lid under water in the bowl and carefully loosen it.

what happens this time?
Title: Re: What's your kitchen science?
Post by: paul.fr on 18/04/2007 14:41:41
what you need


a candle
aluminum foil
a plate
a tall, glass container. I used a glass vase, but you could also use a glass
jar or the chimney from an oil lamp.


what you do


Cut the candle so that it is at least 4 or 5 inches shorter than the glass container. Tear off a piece of foil and crumple it around the base of the candle to form a holder. This will need to be stable enough so that the candle will not fall over when it is moved. Place the candle in the holder on the plate and move the plate from side to side to be sure that the candle is stable enough and won't fall.

light the candle. Let it burn for a few seconds, so that the flame can stabilize. Then move the plate quickly to one side. Watch the flame as you move the plate. If you slide the plate to the right, the flame leans to the left. If you slide the plate to the left, the flame will lean to the right.

Turn the glass container upside down and place it over the candle to form a cover. Be sure that the flame does not reach near the container. You don't want it to get hot and crack. If the flame is too close, blow out the candle and trim it to make it shorter.

Once the flame is the right height, place the container over the candle. Again, slide the plate quickly to one side. Watch the flame carefully.

what happens to the flame this time? and why?
Title: Re: What's your kitchen science?
Post by: DrDick on 18/04/2007 19:52:05
What you need

Rubbing alcohol (usually 70% isopropyl alcohol)
water
paper towel
tongs
ignition source (lighter, aim-n-flame, match, etc.)
pan with lid

What you do

Make a mixture containing about 50/50 alcohol and water.  Since most rubbing alcohol already contains about 30% water, you can use a 2:1 ratio of rubbing alcohol to water.

Soak a paper towel in the alcohol/water mixture.  Pick up the paper towel with the tongs, making sure you don't get your fingers wet.  Light the paper towel with the lighter.  (If it doesn't light, add some more alcohol.)  Be amazed at what happens next.   [:o]

After a time, douse the paper towel by putting it in the pan and putting the lid on.

Dick

[moderator] Be very careful because alcohol burns with an invisible flame [/moderator]
Title: Re: What's your kitchen science?
Post by: paul.fr on 19/04/2007 14:03:12
Excellent, Dr Dick.

what you need


a marble
a drinking glass with straight sides


what you do
Place the marble on a smooth surface. Turn the glass upside down and place it on the table, with the marble inside. Now, the idea is to pick the marble up off the table without touching anything except the glass.


Hold the glass and start sliding it across the table in a tight circle. That should cause the marble to spin around the wall of the glass. If you move the glass faster and faster, the marble will spin faster and faster. Once it is spinning very quickly, slowly lift the glass, being sure to keep it spinning. As long as you hold it very level, the marble should stay in the glass as you lift it.


Why?
Title: Re: What's your kitchen science?
Post by: paul.fr on 19/04/2007 14:21:59
what you need

an orange (You can also use a lemon or other citrus fruit.)
a candle
candle holder


what you do

The first thing to do is peel the orange. You do not have to peel the whole orange, just a few strips.
Place the candle into a holder and light it. Pick up a piece of the orange
peel. Holding it near the flame, bend the peel and squeeze it. Be sure that
the outside of the peel is facing towards the flame.

what happens? why?
Title: Re: What's your kitchen science?
Post by: Seany on 20/04/2007 21:54:13
Great Paul! Loving those experiments, although I haven't done it. I can just imagine the outcome. Awesome. I've tried the marble one when I was young.. Got me astounded! LOL [;D]
Title: Re: What's your kitchen science?
Post by: paul.fr on 21/04/2007 12:05:34
Great Paul! Loving those experiments, although I haven't done it. I can just imagine the outcome. Awesome. I've tried the marble one when I was young.. Got me astounded! LOL [;D]

Thanks, Seany. It would be nice if more people could contribute, hopfully lots of the experiments here you will not find elsewhere on the net. Or not in one place atleast.

what you need

a banana
milk bottle, or A narrow necked glass bottle
3 matches/small pieces of paper


what you do


Peel just enough of the banana to expose the tip. light the matches or pieces of paper and drop it into the bottle. Quickly place the top of the banana into the bottle’s mouth (with the peel on the outside).

what happens?
Title: Re: What's your kitchen science?
Post by: Karen W. on 21/04/2007 14:26:42
Excellent, Dr Dick.

what you need


a marble
a drinking glass with straight sides


what you do
Place the marble on a smooth surface. Turn the glass upside down and place it on the table, with the marble inside. Now, the idea is to pick the marble up off the table without touching anything except the glass.


Hold the glass and start sliding it across the table in a tight circle. That should cause the marble to spin around the wall of the glass. If you move the glass faster and faster, the marble will spin faster and faster. Once it is spinning very quickly, slowly lift the glass, being sure to keep it spinning. As long as you hold it very level, the marble should stay in the glass as you lift it.


Why?


Is it gravity like when you ride the graviton and you are spinning so fast that it holds you up against the wall without letting you fall or away from the walls.Is is the same principle.. That is cool and fun.. my kids are going to like this one.. Well Is it a gravitation effect or what?? LOL
Title: Re: What's your kitchen science?
Post by: Seany on 21/04/2007 17:53:21
Yes.. I forgot what that motion was called.. Well.. You get a bucket of water, filled with water. Hold onto the handle, and spin is round as fast as you can. The water doesn't drop. GREAT! I was so amazed at that when I was younger. [;)]
Title: Re: What's your kitchen science?
Post by: paul.fr on 21/04/2007 18:42:44
what you need


lemonade
Drinking glass
Salt
powdered Jelly mix


what you do


Pour the lemonade into the glass. Add some salt and then some powdered Jelly mix into the glass.

what happens?
Title: Re: What's your kitchen science?
Post by: paul.fr on 21/04/2007 18:44:45
what you need

Clear drinking glass or plastic cup
1/2 cup water
1/2 cup rubbing alcohol
Cooking oil
Eyedropper


what you do


Pour the water into the glass. Tilt the glass slightly and slowly pour in the rubbing alcohol. Don't shake the glass, or the two liquids will mix.

Fill the eyedropper with the cooking oil and lower the tip into the layer of rubbing alcohol, but not into the water. Squeeze out a couple of drops of the oil.

what happens?
Title: Re: What's your kitchen science?
Post by: daveshorts on 23/04/2007 17:59:34
Quote
Thanks, Seany. It would be nice if more people could contribute, hopfully lots of the experiments here you will not find elsewhere on the net. Or not in one place atleast.

I'm afraid mine are going into:
http://www.thenakedscientists.com/HTML/content/kitchenscience/
I've written up a fair few of the older ones since the website changed over.
Title: Re: What's your kitchen science?
Post by: paul.fr on 27/04/2007 10:16:10

I'm afraid mine are going into:
http://www.thenakedscientists.com/HTML/content/kitchenscience/
I've written up a fair few of the older ones since the website changed over.


Not a problem, Dave.

ok, seeing as i have not posted for a while, here is a really simple one

What you need

a bucket
sand
water


What you do

fill the bucket with the sand, the bucket is now full right!
pour the water on to the sand.

what happens and why?
Title: Re: What's your kitchen science?
Post by: paul.fr on 27/04/2007 10:33:27
what you need


a birthday cake (or similar candle holder)
several birthday candles
matches or a lighter
a friend whos birthday it is!


what you do

Place the candles on the cake, grouping them very close together. light the candles. As your friend prepares to blow out the candles, have a lit match or lighter ready.

As soon as the candles are blown out, you will see a column of white smoke rising from the candle. Quickly bring the flame of the match or lighter into this smoke.

what happens?


you dont actually need a birthday cake, or friend whos birthdat it is. But it makes it much better if you have  [;D]



please use caution, when using candles, lighters and matches.
Title: Re: What's your kitchen science?
Post by: paul.fr on 27/04/2007 13:06:25
if you don't try this, then you are really missing out!

What you need


a hand held mirror
2 blank walls or two large sheets of white poster board/ large white paper
A friend
2 chairs


what you do


You need a place where you can stand facing one section of blank, white wall and have another section of blank, white wall to your right. Place one chair with its back against the wall in front of you. Have your friend sit in that chair. Place the other chair in front of your friend, being sure that youhave a section of blank wall on your right. Have a seat in the chair.

Once you and your friend are facing each other, hold the mirror in your left hand. Bring it up to your face against the right side of your nose. Turn the mirror at an angle so that when you look straight ahead, your right eye sees only the white wall beside you. Your left eye should still be able to see your friend.

Both of you should sit very still to make this work well. Hold your right hand up so that you can see its reflection in the mirror with your right eye. Looking straight ahead with both eyes, you should be able to see your friend and your hand. Now move your right hand as if you were using a chalk eraser to wipe your friend's face away.

what happens?
Title: Re: What's your kitchen science?
Post by: paul.fr on 30/04/2007 20:32:06
in other topics it has been suggested that Newton, was wrong about everything. well this is an experiment that will atleast confirm he was right about the laws of motion.

what you need


a bathroom scale
an object that weighs at least a few pounds, like a bag of sugar.


what you do


Start by placing the scales on a flat, hard floor. Step onto the scale and
look at your weight. Now pick up the object you selected. Notice the new reading on the scales. It should be a bit higher for the total of you and the object. So far, everything is just as you would expect.

As you watch the reading on the scale, quickly lift the weight up over your head. Do this as quickly as you can.


what happened?


Next, bring the weight back down as fast as you can, again watching the scale.

what happened this time?
Title: Re: What's your kitchen science?
Post by: paul.fr on 30/04/2007 20:46:51
what you need


a potato
a knife
salt
a plate

what you do


Select a large potato and carefully cut it in half. Place both halves of the potato on a plate, cut side down. Use the knife to carefully dig a hole in the top of each potato. Each hole should be at least big enough to stick the end of your finger into. Leave one just as it is. Into the other hole, put about 1/4 a teaspoon of salt. Set the plate aside and wait about half an hour.

what has happened?

wait another hour or two and reckeck the potato halves, what do you now notice?

Title: Re: What's your kitchen science?
Post by: paul.fr on 01/05/2007 10:17:37
There has been some talk recently about fridges/freezer and cold air falling, warm air rising. her is a little experiment to show cold air falling.

what you need


a refrigerator or freezer
a pitcher or other large container/ or a small cake tin


what you do

firstly, feel underneath or at the bottom of your refrigerator, you should feel the hot air rising.

openg the door to your refrigerator just a tiny bit. Hold one hand at the top of the door and the other at the bottom.

what happens?

Place an empty pitcher or other large container under the door of your refrigerator or freezer.  Once the container is in place, open the door slightly.  After a few seconds, close the door and put your hand into thecontainer. Don't touch the sides. Just hold your hand in the air inside.

what has happened?

Title: Re: What's your kitchen science?
Post by: paul.fr on 02/05/2007 21:11:35
what you need

a mirror
clouds


what you do

look up, you see some nice lovely clouds, unless it's raining then you can go back inside until it stop  [:)] .We all know that clouds are moving quite fast, but when we look up at them they seem to be moving quite slowly. So how do we prove that clouds are moving fast?

place your mirror on the floor, it should be a nice flat surface like a path or pavement. Sit so that you can see the reflection of the clouds in the mirror. Keeping your head still, watch the clouds in the mirror.

what do you see?

try repeating this on a clear night, with the moons reflection instead of the clouds.
Title: Re: What's your kitchen science?
Post by: paul.fr on 02/05/2007 21:25:56
what you need

video camera /mobile phone camera
remote control
dark room


what you do

take your video camera and remore control and sit in the dark room, wait afew minutes for your eyes to adjust to the dark. Now your eyes have adjusted, press a button on your remote control. Do you see anything? Well, no.

Turn your video camera on. Whilst looking through the view finder, or the viewing screen on a new camera, point the remote control at your camera's lens.

what do you see?
Title: Re: What's your kitchen science?
Post by: paul.fr on 05/05/2007 08:01:37
what you need

a bar of ivory soap
a microwave


what you do

place the bar of soap in your microwave and heat for two minutes. for some reason ivory soap works better than the rest, one note of caution. If you overheat the soap it will trigger your smoke alarm.

for a change i will now post what you should see:

after the two minutes, you soap should have expanded up to five times it's original size. like i said this works best with ivory soap. i have tried other soaps and it just melts and sets my smoke alarms off.

highly annoying since i did this at 7am, I'm sure the neighbours don't mind!  [:I]
Title: Re: What's your kitchen science?
Post by: daveshorts on 05/05/2007 08:59:32
It will also fill your microwave with soap flavoured smoke, and I would reccomend that you leave the door open for a while afterwards.
Title: Re: What's your kitchen science?
Post by: paul.fr on 06/05/2007 07:36:06
what you need

table tennis ball
bath


what you do

when you have finished bathing, take out the plug and throw the table tennis ball in to the bath.

what happens?
Title: Re: What's your kitchen science?
Post by: Seany on 06/05/2007 17:33:04
It spins? Right..?
Title: Re: What's your kitchen science?
Post by: paul.fr on 08/05/2007 14:55:41
what you need

a raw egg
a clear glass of hot water


what you do

Be sure to use a clear glass, so you can see what is happening. Fill the glass with hot water from your kitchen sink. We will put the egg into th water, so leave enough room so that the water does not overflow. Your main goal is to have enough hot water so that the egg will be completely under water.

Let the hot water sit for a few seconds, so that any air bubbles can float to the top. Carefully place the egg into the hot water. Watch for a minute.


What do you notice? What do you hear?


I should add a little not here, be careful when handling hot water.
Title: Re: What's your kitchen science?
Post by: paul.fr on 09/05/2007 02:31:29
Oh my, just short of 4,000 views! As a special treat, here is a bit of science, a trick to amase your friends and something to eat. All rolled in to one!!!


What you need


a banana with no brown spots.
some slivered almonds or other nuts
a candle holder
a lighter


what you do

Carefully peel the banana and cut a section about 3 or 4 inches long. You want it to be as straight as possible. You also want to be sure that it has no brown spots.What you are trying for is something that looks like a candle.

Once you have the length of banana, place it into the candle holder. Stick a thin sliver of almond into the top of the banana. it will only burn for a minute or so. That means you have to work quickly.

Once the candle is burning nicely, carry it carefully into the room where someone is sitting. As they watch you carrying your candle in, blow out the almond and bite some of the banana off!

there you go, the science is why the almond burned, the trick is your friends think you have just eaten a candle! and the something to eat........well, that's the banana.


One thing to be careful of is the hot end of the burned almond. It will cool quickly, but I always make sure I have plenty of saliva (spit) on my tongue to be sure it is completely out.
Title: Re: What's your kitchen science?
Post by: paul.fr on 09/05/2007 12:48:07
what you need


a book of safety matches
a large coin
a lighter


what you do



tear the strickin strip off the box of matches and place it on the coin. You don't want it to hang over the edge, so you will probably have to either bend it or tear it in half.

Carefully, use the lighter to set the strip alight. When the strip has burned, carefully move it aside. On the coin, you will see a brown, oily liquid. Rub your finger across it, to get the stuff on your finger. Then rub your finger and thumb together. 


what happens?

ps, this will work best if you have plenty of light and a dark background.


As always, be careful when using matches and lighters.
Title: Re: What's your kitchen science?
Post by: paul.fr on 13/05/2007 09:43:18
what you need


several coins


what you do


Open your right hand and bring it up so that it is on your right shoulder, with the palm facing upwards. Start with three coins. Place them in a stack and balance them on your elbow. Now comes the fun part. You are going to sweep your hand downwards as fast as you can. Be prepared to close your hand when it runs into the coins.

Do this well away from anything glass, or easily broken.
Title: Re: What's your kitchen science?
Post by: paul.fr on 14/05/2007 10:26:11
It occured to me whilst reading through some of these experiments, that not all of them work! No, i'm not just posting rubbish experiments - honest.

But i have never made the lemon battery tingle my tongue, and the surface tension ones with matchsticks and washing up liquid never work for me.Why? no idea.

I previously posted an alternative surface tension experiment with food colouring, but never an alternative potato or fruit battery. battery. So here is one.

What you need


A potato
A nail or paper clip
a piece of copper wire
headphones


What you do

Stick the nail / paperclip in to the potato, about half an inch away stick the copper wire in. If you look at the plug from the headphones, you will see that the metal part is made of two or three sections. Put on the headphones. Touch one piece of metal to one section of the headphones and the other piece of metal to one of the other sections.

Listen carefully, what do you hear?

If the plug has three sections, then you may have to try touching different sections for this to work.

Did you hear anything? Why not trt repeating it with other fruits and metals to see if what you hear is in anyway different.
Title: Re: What's your kitchen science?
Post by: paul.fr on 14/05/2007 11:02:31
Climate change, well we have all heard of it. Maybe your kids have asked questions as to what will happen if the polar icecaps melt.

Well, the northern icecap is easy to explain in a simple experiment.
Question, what will happen to the sea level if the polar icecap melts?

what you need
a glass
water
ice cubes


what you do


Try to get a large lump of several ice cubes frozen together. You can place several ice cubes into a bowl and leave it in the freezer over night and they should freeze together. Place the ice cubes into a glass or bowl. Add enough water to fill the glass to the top. Add as much water as you can, until the glass will not hold any more without overflowing.

Now, look carefully at the glass, water and ice. There is quite a bit of ice sticking up above the glass ( the visable part of the icecap)

what will happen when the ice melts?
Title: Re: What's your kitchen science?
Post by: paul.fr on 14/05/2007 20:34:58
What you need


A tall glass
Ice
Fruit cordial Orange juice
Green food colouring
a straw


What you do



Fill your glass with ice. Carefully pour in the fruit cordial until the glass is a third full. Slowly pour the orange juice into the glass so it sits on the berry cordial. Then tip a little bit of food colouring in. Let the food colouring spread out into the orange juice.

If you gently push a straw into the drink down the side of the glass watch what happens to the food colouring and orange juice. You should also be able to drink one layer at a time, by gently pushing the straw down the side of the glass.

Well, the answer is slighly given away, but, what happens?
Title: Re: What's your kitchen science?
Post by: paul.fr on 14/05/2007 20:39:35
here is a similar one to the last, but this is just for Dads.

what you need


2 glasses
water
Whisky
a hankerchief
A straw


what you do

Put a tot of whisky in one glass and a tot of water in another. Take a clean handkerchief and lay it down the inner side of the water glass until it just touches the water. Gently pour the whisky down the handkerchief.

What happens?

Now use your straw to drink one or the other, or simply to mix things up. This works great at parties!
Title: Re: What's your kitchen science?
Post by: paul.fr on 15/05/2007 10:42:31
Having trouble getting the kids to brush their teeth? This experiment demostrates the way the bacteria in your mouth, release acid which destroys the enamel on your teeth!

The egg and shell bing your tooth and the enamel, and the vinegar being the acid released by the bacteria.



What you need


1 egg
1 small plastic container with a lid
Vinegar


What you do


Place the egg into the container and pour in enough vinegar to cover it. Put the lid on the container and leave it for three days.

what happens to the egg?
Title: Re: What's your kitchen science?
Post by: kdlynn on 16/05/2007 03:14:53
ok if you could all try this and let me know if the same thing happens to you, that would be great. i've done it twice. what you need: several candles the same size        what you do: freeze half of the candles. light all of them at the same time. wait and see which burns faster. the results i have gotten have had me baffled for a few days now!
Title: Re: What's your kitchen science?
Post by: paul.fr on 16/05/2007 09:33:39
Did you know that there is now a rss feed, for the excellent Kitchen Science section of the main Naked Scientist site? These are the experiments that are conducted on the show.

This is the url for the rss feed: http://www.thenakedscientists.com/rss/kitchen_science.xml


Alternitavley, if you use widgets / widsets on your internet enabled phone. You can download a widget from this link.
http://www.widsets.com/widgets?publicwidgetid=W2222   (https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi154.photobucket.com%2Falbums%2Fs262%2Fpf0604%2Fexperiment.png&hash=d46906fc1acbe9ae3c517ca1ddd1abbe)   (https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi154.photobucket.com%2Falbums%2Fs262%2Fpf0604%2Flarge.gif&hash=c601218ae2856cac69898ed7aeaa840c)


If the above link does not take you to the specific widget, just type kitchen science in to the search bar.

RSS (Really Simple Syndication) provides a convenient way to syndicate information from a variety of sources, including news stories, updates to a web site or basically any type of publication. Regardless of the purpose for which the RSS file is being used, by watching this XML file, you can quickly and easily see whenever an update has occurred.

You can use the rss feed in you "home page", if you use yahoo or msn for example.




Title: Re: What's your kitchen science?
Post by: paul.fr on 16/05/2007 09:48:15
What you need

two glasses
a jug or pitcher
ice cubes
water


what you do


Fill your jug with water, take one of the glasses and put 3 or 4 ice cubes in it. Wait a minute and fill the glass with water.

Take your second glass, and 1/2 fill it with water, and add the same quantity of icecubes as the first glass. If it needs more water to fill the glass, then you can add some more.

in which glass do the icecubes melt first?
Title: Re: What's your kitchen science?
Post by: kdlynn on 16/05/2007 09:50:52
that one sounds interesting
Title: Re: What's your kitchen science?
Post by: paul.fr on 16/05/2007 20:40:17
what you need

a few pieces of chalk
vineger
lemon juice
a saucer


what you do


Put a piece of chalk on a saucer and place 3 or 4 drops of vinegar on the chalk.

What happens?

Try a few drops of lemon juice on the chalk, now what happens?
Title: Re: What's your kitchen science?
Post by: paul.fr on 16/05/2007 21:30:13
This weeks podcast and radio show was about bacteria, fungi and viruses. This experiment demonstrates how you spread the common cold by sneezing.

the pump and water represent what happens when you sneeze.

What you need


Bicycle pump
Some water
A large sheet of paper
Some tape
a friend


What you do


Tape the paper up on a wall and stand back three lengths of the bicycle pump from it. Pull the pump handle of the bicycle pump back then put a couple of drops of water into the end of the bicycle pump hose. Direct the hose at the paper then push down hard on the pump handle.

what happens

to make it real, direct the pump at your friend. Make sure he / she is happy with you doing this first.
Title: Re: What's your kitchen science?
Post by: paul.fr on 17/05/2007 11:47:31
what you need


3 pieces of white paper
Red crayon or felt tip
Blue crayon or felt tip


what you do


Draw a red shape on one piece of white paper and a blue shape on another. Stare hard at the red shape for a few minutes then stare at the blank paper.

What happens?

 
Repeat the experiment with the blue shape.
What happens?
 
Title: Re: What's your kitchen science?
Post by: paul.fr on 18/05/2007 10:02:18
What you need

 
A glass of water
Lemon juice
Castor sugar
Baking soda


What you do

 
Squeeze some lemon juice into the glass of water and stir in a teaspoon of castor sugar. Taste the drink.

add a teaspoon of baking soda.
What happens? What does it taste like?
Title: Re: What's your kitchen science?
Post by: paul.fr on 18/05/2007 10:21:26
what you need

 
Several sheets of newspaper
Several sheets of A4 paper
An inkpad
A pen
Soap and water
Paper towels


What you do


Spread the newspaper down first and have the soap, water and paper towels nearby. Write each person’s name at the top of the paper and have them put their prints onto their page one by one. Get them to wash their hands straight away!


When the prints are dry compare them and see if any of the prints are similar. Maybe some are Whorl patterns, maybe some are loops and some might be arch patterns.


Have them make another set of prints on paper without their name on top and see if you can match their new set with the named set.

If you have brothers or sister, try doing this with them. If you have a twin, what will your results be?

topic link

What causes "fingerprints", and why do we all have different ones? http://www.thenakedscientists.com/forum/index.php?topic=6371.0
Title: Re: What's your kitchen science?
Post by: paul.fr on 20/05/2007 21:30:55
what you need


Jelly
a ladel, or large spoon
glass or clear plate


what you do


Make you jelly. Before letting it set, fill your ladel with the jelly and pop it in to your fridge. After about 3 - 4 hours it should be set.

remove the jelly from the ladel mould, if the jelly does not come out with ease, run hot water over the back of the ladel to free it.

Now, set your jelly mould in the centre of your glass plate. Place the plate on top of a newspaper or book.

what happens?

topic link

"magnifying Glass" http://www.thenakedscientists.com/forum/index.php?topic=7776.0
Title: Re: What's your kitchen science?
Post by: paul.fr on 20/05/2007 21:42:37
what you need

Scissors
a balloon
an empty  2 litre drink bottle, with lid on


what you do

Use the scissors to cut the top off your drink bottle, cut about 2 inches below the lid. Poke a small hole in the bottle lid, then inflate your balloon.

with the neck of the balloon, tightly pinched. Stretch the mouth of the ballooon over the bottle lid, now let go of your grip on the balloon.

what happens?


oops, forgot to mention. do this on either a tabletop or non-carpeted floor.

topic link

"Eactly how does a hover craft work ?" http://www.thenakedscientists.com/forum/index.php?topic=6951.msg73102#msg73102
Title: Re: What's your kitchen science?
Post by: paul.fr on 22/05/2007 01:24:52
what you need


A darkened room
A glass dish of water
A small mirror
A lamp
A large piece of black card with a slit cut in it to let the light through
A small piece of white card


What you do


Sit the small piece of mirror in the dish of water so that it sits at an angle facing towards the black cardboard. Shine the lamp through the slit in the black card (don’t get it too close) and keep moving the mirror until it reflects the light back onto the black card. Put the white card in front of the black card so that the light reflected from the mirror falls on it. Keep moving the mirror until you can see a rainbow on the white card
Title: Re: What's your kitchen science?
Post by: paul.fr on 22/05/2007 01:32:54
what you need


A window
Some cotton wool balls
a friend


what you do


Have your friend stand on the other side of the window. Explain what you’re going to do. Gently through a cotton wool ball at the window at the level of their eyes and see if they blink. They may try really hard not to blink but it’s a reflex action and they will probably blink every time.


topic link

eye lids ??? http://www.thenakedscientists.com/forum/index.php?topic=1646.0
Title: Re: What's your kitchen science?
Post by: paul.fr on 23/05/2007 22:31:08
what you need

a balloon
a straw
string, lots of
2 fixed points
selotape


what you do

Cut the straw in half, and thread your strong through it. tie both ends of the string to two fixed objects (two chairs, a washing line...)now blow up the balloon but do not tie it off.

carefully use the selotape to stck the straw to the balloon, now let go.

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi154.photobucket.com%2Falbums%2Fs262%2Fpf0604%2Fstool.gif&hash=c0370c1c9ef66d4ea10d69ea02d2c8a9)

what happens

try repeating with longer and longer string and different shaped balloons.

topic link
Title: Re: What's your kitchen science?
Post by: paul.fr on 30/05/2007 00:50:28
what you need

A hair dryer
table tennis ball
Tissue paper


what you do


Blow a stream of air straight up. Carefully balance the ball above the airstream. Pull it slowly out of the flow, what do you notice?

Let go of the ball, now what happens?
With one hand, pull the ball partially out of the airstream. With the other hand, dangle a piece of tissue paper and search for the airstream above the ball, what happens?


Balance the ball in the airstream and then move the blower and the ball toward a wall (try the corner of a room). what happens?
 

Title: Re: What's your kitchen science?
Post by: paul.fr on 30/05/2007 01:04:58
what you need


A Lighter or Matches
small candle
Tall Round Container


what you do


Place the candle just behind the round container. Light the candle, blow against the round container from the front and at candlelight level.

what happens?
Title: Re: What's your kitchen science?
Post by: paul.fr on 30/05/2007 01:12:46
what you need


a uncooked potaot
a straw, or two


what you do


Place the potato on a table top. Hold the straw at the top (without covering the hole) and try to stab the straw into the potato.

what happens?

Now hold your thumb over the hole in the top of another straw and try to stab this straw into the potato.

whathappens now?
Title: Re: What's your kitchen science?
Post by: paul.fr on 30/05/2007 15:27:06
what you need


a Coin
Water
Plastic or other non-transparent bowl


what you do


Put the coin in the bowl and walk backwards until you cannot see the coin in the bowl any more. Have someone pour water slowly into the bowl carefully watch the bowl from where you are standing.

when the bowl is full of water, what do you see?
Title: Re: What's your kitchen science?
Post by: paul.fr on 01/06/2007 22:01:14
what you need

A candle
a carrier / plastic bag
two elastic bands
a long tube (empty kitchen roll type tube)
scissors


what you do


cut two circles from the plastic bag, and make a hole in the middle of one of the circles. Put one on each of the ends of your tube and pull then tightly (tight as a drum skin), seruce them in place with the elastic bands.

Light your candle. With your tube pointing at the candle, give the backend of the tube a sharp whack.

what happens?
Title: Re: What's your kitchen science?
Post by: paul.fr on 02/06/2007 01:47:56
what you need


Imagination! or
sand
2 tablespoons of baking soda
Half a cup of vinegar


what you do


Make a volcano shape in the sand and hollow out a well in the top of the volcano. Put in the baking soda and then pour in the vinegar.

What happens?

Title: Re: What's your kitchen science?
Post by: paul.fr on 02/06/2007 16:19:38
Well, it's the weekend. So why not let the kids make their own silly putty.

what you need


PVA glue (15ml, or 3 teaspoons),
talcum powder (5 ml, or 1 teaspoon),
food colouring (a few drops),
water (25 ml, or 5 teaspoons),
Borax solution (5 ml, or 1 teaspoon),
a glass tumbler,
a plastic bag,
some paper towels.


what you do


Measure the glue into the tumbler (it doesn't have to be too exact). About 15ml (three teaspoonfuls) is enough. The more glue you add the more silly putty you'll get.
Next add about 25ml (5 teaspoons) of water to the tumbler and sprinkle in one teaspoon of talc. Stir thoroughly with the spoon to mix the contents of the tumbler until you have a smooth grey paste. Break up any clumps of talc that form at the sides.
Now add drops of the food colouring until you get the colour you want, but be careful not to add too much.

You now have a tumbler full of colourful, watery glue. It's time for the magic ingredient: borax. Make a borax solution by stirring a heaped teaspoon of borax into a glass of water. Add a teaspoonful of this borax solution to your tumbler of silly putty and stir. Once the borax is mixed in thoroughly, take the spoon out and pull the putty off it.

Work the solid material with your hands for a few minutes. At first it will be quite slimy, but soon it will become smooth and dry. Have the paper towels ready so you can wipe any colour and goo off your hands. You should lay out your plastic bag to protect the work surface. And there you have it: silly putty.

Borax powder is readily available from pharmacies and hardware shops, but you must be careful with it, as it is harmful when swallowed. Always wash your hand after handling Borax



topic link

WHAT EXACTLY IS BORIC ACID< AND WHERE DOES IT COME FROM? http://www.thenakedscientists.com/forum/index.php?topic=6814.0

the properties of silly putty http://www.thenakedscientists.com/forum/index.php?topic=8140.new#new
Title: Re: What's your kitchen science?
Post by: paul.fr on 03/06/2007 15:55:58
what you need


A large iron nail (about 3 inches)
About 3 feet of THIN COATED copper wire
A fresh D size battery
Some paper clips


what you do


Leave about 8 inches of wire loose at one end and wrap most of the rest of the wire around the nail. Try not to overlap the wires.

Cut the wire (if needed) so that there is about another 8 inches loose at the other end too. 

remove about an inch of the plastic coating from both ends of the wire and attach the one wire to one end of a battery and the other wire to the other end of the battery. It is best to tape the wires to the battery - be careful though, the wire could get very hot!

Put the point of the nail near a few paper clips, what happens?


topic link


How fast does a magnet attract ?..and other magnet questions ! http://www.thenakedscientists.com/forum/index.php?topic=6696.0
Title: Re: What's your kitchen science?
Post by: Karen W. on 03/06/2007 20:49:47
Well, it's the weekend. So why not let the kids make their own silly putty.

what you need


PVA glue (15ml, or 3 teaspoons),
talcum powder (5 ml, or 1 teaspoon),
food colouring (a few drops),
water (25 ml, or 5 teaspoons),
Borax solution (5 ml, or 1 teaspoon),
a glass tumbler,
a plastic bag,
some paper towels.


what you do


Measure the glue into the tumbler (it doesn't have to be too exact). About 15ml (three teaspoonfuls) is enough. The more glue you add the more silly putty you'll get.
Next add about 25ml (5 teaspoons) of water to the tumbler and sprinkle in one teaspoon of talc. Stir thoroughly with the spoon to mix the contents of the tumbler until you have a smooth grey paste. Break up any clumps of talc that form at the sides.
Now add drops of the food colouring until you get the colour you want, but be careful not to add too much.

You now have a tumbler full of colourful, watery glue. It's time for the magic ingredient: borax. Make a borax solution by stirring a heaped teaspoon of borax into a glass of water. Add a teaspoonful of this borax solution to your tumbler of silly putty and stir. Once the borax is mixed in thoroughly, take the spoon out and pull the putty off it.

Work the solid material with your hands for a few minutes. At first it will be quite slimy, but soon it will become smooth and dry. Have the paper towels ready so you can wipe any colour and goo off your hands. You should lay out your plastic bag to protect the work surface. And there you have it: silly putty.

Borax powder is readily available from pharmacies and hardware shops, but you must be careful with it, as it is harmful when swallowed. Always wash your hand after handling Borax



topic link

WHAT EXACTLY IS BORIC ACID< AND WHERE DOES IT COME FROM? http://www.thenakedscientists.com/forum/index.php?topic=6814.0

the properties of silly putty http://www.thenakedscientists.com/forum/index.php?topic=8140.new#new

This is way cool, But what is PVA Glue??? Plastic Vinyl adhesive??? LOL I am guessing am I close ??? LOL
Title: Re: What's your kitchen science?
Post by: paul.fr on 04/06/2007 09:49:20
Karen, PVA glue is PVA glue Poly vinyl acetate. It is white and tends to come in tubes, i'm sure you use it at school.
Title: Re: What's your kitchen science?
Post by: paul.fr on 04/06/2007 09:54:52
what you need

two tabletennis balls (ping pong balls)
string
sellotape
a straw


what you do


cut two 30cm lengths of string, and sellotape one to each of the table tennis balls. Attach the free end of each string to the top of your door frame, there should be about 3/4 of an inch gap between the balls when they are hung.

Now, use the straw to blow air on to one of the balls. What happens to the gap between the balls?

steady the balls and repeat, this time blowing the air at the gap between the balls. What happens this time?
Title: Re: What's your kitchen science?
Post by: paul.fr on 05/06/2007 09:50:54
what you need

a tin can
can opener
cardboard
sellotape
match or lighter
wooden splint or paper


what you do


remove both ends of the tin can, tape a piece of cardboard over one end, and cut a 1" hole in the center of the cardboard. Tape a disk of thin card over the other end (or you could cut a balloon in half and stretch it over the opening.)

Light your splint or paper and put it in the can through the hole you cut out, leave it there until the can is full of smoke. remove and extinguish the flame.

Tap the bottome gently (the end with no hole in it) what happens?

This will work best in a darkened room while placing the can between you and a bright table lamp and aiming at the ball

Title: Re: What's your kitchen science?
Post by: paul.fr on 07/06/2007 20:06:07
What you need



4 balloons
an upside-down desk or some other flat-bottomed object that can survive you standing on it
a carpeted floor
a table, pole or wall you can use to help yourself balance.
friends, the more the merrier



what you do



Check that there is nothing sharp on the desk or floor that could burst the balloons. Half-inflate four balloons and tie them off, place one balloon under each corner of the desk.

Have your assistant hold the desk still. They shouldn't try to take the weight, just help keep it balanced. Make sure they do not put any of their fingers under the desk - they might get squashed!

Carefully step up onto the desk. You can use another table or a pole to help you balance as you climb up. Unless something sharp bursts them, the balloons should be able to support your weight.

how many people can you get on one desk before the balloons pop?
Title: Re: What's your kitchen science?
Post by: paul.fr on 08/06/2007 10:28:26
what you need

matchsticks
an eye-dropper
water
a plate.


what you do


Bend five matchsticks in the middle. Be careful not to break them. Arrange the matchsticks on the plate so they are all touching, with the bends in the centre. It should look like a five-pointed asterisk.

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi154.photobucket.com%2Falbums%2Fs262%2Fpf0604%2Fmatchsticks.jpg&hash=c53a9b7bdaea7e5287f9c6cd82e135f4)

Use the dropper to place three or four drops of water in the centre of the matches and watch the matches for a couple of minutes.

What happens?

Title: Re: What's your kitchen science?
Post by: paul.fr on 08/06/2007 11:23:49
well, its the weekend again. did you make the silly putty last weekend? for the kids this weekend, we have home made playdough.


what you need


1 cup baking soda
1/2 cup corn starch
3/4 cup water
adult supervision


what you do


mix the baking soda and corn starch in a pot.  Use hands to make sure all the lumps are broken up.  Add water.  The adult should put the pan on the stove over medium heat and stir constantly.  As soon as the mixture gathers together, remove from the heat.  When it cools, knead it into a smooth playdough.

Note: Don't over cook this playdough or it will crumble when the children use it.

you can add food colouring, to make different coloured playdough.

sounds obvious, but please supervise the kids when heating the mixture.

be sure to visit the official kitchen science section on the main website http://www.thenakedscientists.com/HTML/content/kitchenscience/
for more fun experiments, they even include nice pictures!
Title: Re: What's your kitchen science?
Post by: paul.fr on 11/06/2007 11:01:39
what you need


a margarine container
a balloon
a straw
a rubber band
plasticine
scissors
something that will pierce the margarine container to make a hole big enough to fit a straw through.


what you do


Find a clean, rectangular, margarine container and carefully make a hole in the centre of one of the shorter sides about 1 cm from the bottom.
Cut a straw in half and insert one end into the neck of a balloon. Fix the balloon firmly to the straw with a rubber band.
Push the straw through the hole in the marg container and seal it in place with plasticine. Weigh the back of the marg container with more plasticine in the centre. Blow the balloon up through the straw and pinch the end to keep the air inside.
Put the boat in the water, let go.

What happens?

Title: Re: What's your kitchen science?
Post by: paul.fr on 12/06/2007 01:20:52
what you need


paper
pen felt-tip or marker pen
scissors



what you do


Start with a long rectangle made from your paper. Give the rectangle a half twist and join the ends so that A is matched with D and B is matched with C.

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi154.photobucket.com%2Falbums%2Fs262%2Fpf0604%2FMobius.gif&hash=8e442ce1c8bfa0ddf44ab6093bad728a)

start midway between the "edges" of a Möbius Strip and draw a line down its center; continue the line until you return to your starting point. Did you ever cross an edge?

Next, hold the edge of a Möbius Strip against the tip of a felt-tipped highlighter pen. Color the edge of the Möbius Strip by holding the highlighter still and just rotating the Mobius Strip around.

Were you able to color the entire edge?

Now, with scissors cut the Mobius Strip along the center line that you drew. Then draw a center line around the resulting band, and cut along it.

what happens?


topic link

are there practical applications for a mobius strip? http://www.thenakedscientists.com/forum/index.php?topic=8246.0
Title: Re: What's your kitchen science?
Post by: paul.fr on 13/06/2007 19:50:41
make your own face pack / mask!


what you need


one banana
one tablespoon of honey
one drop of rose oil or sweet almond oil
one teaspoon of lemon juice
one tablespoon of oatmeal
one teaspoon of wheat germ oil
one egg yolk.


what you do


Mash the banana and mix in all of the ingredients except for the rose (or almond) oil. Mash the mixture until it forms a smooth paste. If it is too thick you can add a little bit of water.
Mix in the rose (or almond) oil.
Time to try out your face-mask! Apply the mixture to your face and neck, and rest for 10 minutes.
Wash off the face-mask. You should feel fresh and relaxed.

Our skin has a protective barrier of fats that clump together and create a waterproof layer to keep water in and foreign substances out. Cold or hot weather, wind, air-conditioning and heating can damage this layer of skin, making it dry and flaky.

When you smear the banana mixture on your face, the fat molecules in the banana and rose oil form a temporary waterproof layer over your face, giving your skin cells a chance to rebuild their moisture levels.

The oatmeal in the facemask can help acne – the small grains gently exfoliate your face, removing dead skin and dirt. Honey is well-known for its medicinal properties and it has been used for centuries to treat a variety of diseases. It's been shown to reduce swelling and inflammation in wounds and in some cases can kill germs lurking there. Plus, it can help damaged skin recover more quickly.

This is how i keep my youthful good looks!  [:-[]
Title: Re: What's your kitchen science?
Post by: paul.fr on 14/06/2007 09:46:46
what you need


a tall glass or plastic container
some vegetable oil
ice (try adding some food colouring to make it easier to see).


what you do


Fill the glass with oil. Drop a block of ice into the glass. The ice should float in the middle of the oil.
Watch the ice as it melts.

what happens?
Title: Re: What's your kitchen science?
Post by: paul.fr on 15/06/2007 20:30:59
what yo need

paper


what you do

well, this weekends "experiment" is folding paper. I'm sure you have all heard that it is impossible to fold paper 10 times. Well what you need to do this weeken is just that, fold a piece of paper in half, and in half again, and so on for a total of 10 times.

This has been done, in 2001 by a school girl! Can you get anywhere near her record? I will post the answer as to how she accomplished this on Monday, have a happy paper folding weekend.

Edit: I should add that the record she achieved was 12 folds!
Title: Re: What's your kitchen science?
Post by: Batroost on 15/06/2007 21:24:06
Simple Underwater fireworks?

what you need

A clear glass
Water
Any kind of cooking Oil
Food colour

What you do

Fill the glass approximately 2/3 full with water. Then pour in the oil (over the back of a spoon is best) to near the top of the glass. You'll soon have two clearly defined layers with the oil on top.

Next add small drops of food colour - an eye dropper works best.

Watch the food colour in the oil and then the water and see the differences. Try different colours.

Hint: if things get 'stuck' try prodding with something sharp...
Title: Re: What's your kitchen science?
Post by: Batroost on 15/06/2007 21:39:09
What you need

A cup of water
An ice cube
A length of cotton thread
salt

What you do

Float the ice cube in the glass of water. Tie a loop in th thread and lay it gently on top of the ice cube. sprinkle a little salt on top of the thread and then wait for one minute. When you pull on the thread you should be able to lift the ice cube out of the water!

(The salt lowers the freezing point of the ice and causes it to melt. It then re-refreezes around your thread, trapping it in the ice).
Title: Re: What's your kitchen science?
Post by: Batroost on 15/06/2007 21:43:28
How to keep a balloon inflated with nothing sealing the end...!

What you need
A plastic bottle
A balloon

What you do
Make a small hole near the bottom of the bottle with something sharp. Put the body of the balloon in the bottle with the end opened around the bottle's neck.
Now blow into the balloon, inflating it inside the bottle - air will blow out of the hole. Before you take your mouth away from the balloon, cover the hole in the bottle with your finger.

Title: Re: What's your kitchen science?
Post by: paul.fr on 16/06/2007 23:47:57
Great experiments, Batroost. I hope you continue to contribute to this topic.

What you need


Celery
Food colouring
A petri dish, or small clear glass


what you do


Cut a piece of celery, like this:

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi154.photobucket.com%2Falbums%2Fs262%2Fpf0604%2Fcelery1.jpg&hash=a471687cad0b7e069e68b732edbaaaef)

use a short piece of celery with the leaves still on and place it in a few centimetres of food colouring in water. Leave it for a day or so then carefully cut into the celery long ways to see where the colour has reached.

What does the celery look like now?

Don't forget, there are more experiments to be found on the main website: http://www.thenakedscientists.com/HTML/content/kitchenscience/

Over at Chaos: http://www.chaosscience.org.uk/pub/public_html/index.php

or via the rss feed: http://www.thenakedscientists.com/rss/kitchen_science.xml
Title: Re: What's your kitchen science?
Post by: paul.fr on 18/06/2007 08:43:03
what yo need

paper


what you do

well, this weekends "experiment" is folding paper. I'm sure you have all heard that it is impossible to fold paper 10 times. Well what you need to do this weeken is just that, fold a piece of paper in half, and in half again, and so on for a total of 10 times.

This has been done, in 2001 by a school girl! Can you get anywhere near her record? I will post the answer as to how she accomplished this on Monday, have a happy paper folding weekend.

Edit: I should add that the record she achieved was 12 folds!

Well, here is how Britney Gallivan (of Pomona, California) solved the problem.

The first solution was for the classical fold-it-this-way, fold-it-that-way method of folding the paper. Here you fold the paper in alternate directions. She derived a formula relating the number of folds possible (n) to the width (w, of the square sheet you start with) and the material's thickness (t):

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi154.photobucket.com%2Falbums%2Fs262%2Fpf0604%2F2.gif&hash=538252c971cf6e8642c46c4a1451dce0)

The second solution was for folding the paper in a single direction. This is the case when you try to fold a long narrow sheet of paper. She derived another formula relating the number of folds possible in one direction (n) to the minimum possible length of material (l) and the material's thickness (t):

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi154.photobucket.com%2Falbums%2Fs262%2Fpf0604%2F1.gif&hash=fbb6cf9fa981656150c09ff71b9e3101)

When she looked closely, she found that if you are trying to fold the sheet as many times as possible, there are advantages in using a long narrow sheet of paper.

Her formula told her that to successfully fold paper 12 times, she would need about 1.2 km of paper.

After some searching she found a roll of special toilet paper that would suit her needs - and that cost US $85. In January 2002, she went to the local shopping mall in Pomona. With her parents, she rolled out the jumbo toilet paper, marked the halfway point, and folded it the first time. It took a while, because it was a long way to the end of the paper. Then she folded the paper the second time, and then again and again.

After seven hours, she folded her paper for the 11th time into a skinny slab, about 80 cm wide and 40 cm high, and posed for photos. She then folded it another time (to get that 12th fold essential for her extra maths credit), and wrote up her achievement for the Historical Society of Pomona in her 40 page pamphlet, "How to Fold Paper in Half Twelve Times: An "Impossible Challenge" Solved and Explained". She wrote in her pamphlet, "The world was a great place when I made the twelfth fold."
Title: Re: What's your kitchen science?
Post by: paul.fr on 18/06/2007 18:21:30
This weeks radio show was about Forensic Science, in light of that. Here is an experiment involving chromatography.

what you need


paper towel
scissors
a jar
felt-tipped pens and markers
two paper clips
water.


what you do


Cut some absorbent paper (such as paper towel) into strips about 2 cm wide. The length isn't really important and will depend on the size of the jar you hang them in.

Draw a small circle 1 cm from the bottom of the paper with different black markers or felt-tipped pens.
Fill a clean jar with about 1 cm of water and carefully place the paper into the jar making sure that the bottom of the paper is in the water. The circle must be ABOVE the water level. Use paper clips to hold the paper upright in the jar. Watch the water rise up the paper.

After a few minutes remove the paper from the jar. Notice how different colours in the ink travel up the paper at different speeds.

Now try some different colour pens and markers. Can you see any differences?

Did you have any pens for which the ink did not separate? If so, repeat the experiment using methylated spirits instead of water in the jar. Try out a variety of pens. Can you see any differences? 

The method used to compare inks is called chromatography. It involves separating the ink in each of the pens. As the solvent (water) rises up the paper, the different colours of the ink separate.

Ask your family to play your suspects. Have them use specific pens for the job and see if you can figure out which ink comes from which pen and nab the criminals in your family...tip: It's always the little sister  [;)]
Title: Re: What's your kitchen science?
Post by: paul.fr on 19/06/2007 11:46:43
what you need


A pan or bowl that has a flat bottom
a candle
water
a lighter
a glass jar, jam jar type
a large glass bottle


what you do



Start by lighting the candle and letting some of the melted wax drip onto the
center of the pan. Quickly set the base of the candle into the liquid wax,
so the candle will stay in place. Add about an inch of water to the pan.

Turn the glass jar upside down, so that the opening is at the bottom. Place
the jar over the candle and set it down into the water.

Watch what happens after the candle goes out. Now repeat, this time with the large glass bottle.
Title: Re: What's your kitchen science?
Post by: paul.fr on 20/06/2007 10:39:49
what you need


4 white posterboards or pieces of paper 
Bright red, green, and blue construction or contact paper
Small piece of black construction or contact paper, or black marking pen
Scissors
Glue or glue stick (if you are using construction paper)


what you do


Cut the same simple shape, such a bird or a fish, from each of the three colored papers. Glue each shape on its own white board. Leave one white board blank. Cut a small black eye for each bird or fish or draw one in with the marking pen. If you choose a bird as the shape, draw the outline of a birdcage on the blank board; if you choose a fish, draw a fishbowl, etc.

Place the boards in a well-lit area.

Stare at the eye of the red bird for 15 to 20 seconds and then quickly stare at the birdcage. You should see a bluish-green (cyan) bird in the cage. Now repeat the process, staring at the green bird. You should see a reddish-blue (magenta) bird in the cage. Finally, stare at the blue bird.

What colour is the bird now?
Title: Re: What's your kitchen science?
Post by: Batroost on 20/06/2007 19:21:23
How to make a messy (but simple) rocket...

What you need

A lemonade bottle
Water
Vinegar
Bicarbonate of soda or baking powder
Some cardboard (maybe)
A cork that fits reasonably tightly into the neck of the bottle


What you do


Make a cardboard nosecone and fins for the lemonade bottle rocket (not compulsory!).
Fill the bottle to around the half way point with water and vinegar - I've used about a 10:1 water:vinegar mix. The next bit you have to do very quickly.... tip in two or three generous spoonfulls of bicarbonate of soda, push the cork in and upend the bottle so that the neck points downards. Run away...

The bicarb. will react with the acidic water to produce carbon-dioxide. This will bubble to the top of the bottle, increasing the pressure inside until the cork is forced out. Then the pressure of the gas pushes the water out (down) and Newton's law of action-reaction lifts the rocket into the air.

Like so...

 [ Invalid Attachment ]

This rocket flew three times before being retired. I got covered in water/vinegar and bicarb. - so it's a good idea to have a pair of goggles to protect your eyes.


Title: Re: What's your kitchen science?
Post by: paul.fr on 21/06/2007 02:05:35
what you need


A clear plastic bottle or jar with a tight-fitting srcew on lid
Liquid hand soap that has glycol stearate in it
Water
Food coloring
Clear tape


what you do


Fill the bottle or jar about 1/4 full with liquid soap. Add a drop or two of food coloring. The coloring will make the swirls easier to see.

Turn on your tap so you have just a trickle of water. Use that to fill up the rest of the bottle. (If you run the water too hard, you'll get foam.) Make sure that the water fills the bottle all the way to the very top.
 

Screw the cap on the bottle. Turn the bottle upside-down a few times to mix the soap and water. If you get foam, take the cap off and trickle some more water into the bottle. The foam will run over the edge. Recap the bottle tightly.

Dry the bottle and the cap, then wrap clear tape around it so the bottle won't leak.
 

Twirl the bottle slowly. What do you see? What happens when you stop twirling the bottle? What happens if you spin it quickly?

Try shaking the bottle up and down or side to side. What different patterns do you see inside the bottle?
 
Title: Re: What's your kitchen science?
Post by: paul.fr on 22/06/2007 12:18:00
what you need


A glass jar or clear drinking glass
Vegetable oil
Salt
Water
Food coloring


what you do


Pour about 3 inches of water into the jar then about 1/3 cup of vegetable oil. When everything settles, is the oil on top of the water or underneath it?
 
add one drop of food coloring to the jar.

Shake salt on top of the oil while you count slowly to 5. Wow! What happens to the food coloring? What happens to the salt?

Add more salt to keep the action going for as long as you want.

This is similar to a kitchen Science Experiment conducted by Dave on the radio show, here is a link: http://www.thenakedscientists.com/HTML/content/kitchenscience/exp/build-a-lava-lamp/


 
Title: Re: What's your kitchen science?
Post by: paul.fr on 25/06/2007 16:56:17
4th of July Celebrations

what you need


Box of Epsom Salts
Colorful pipe cleaners
Straight-sided, container that can hold about 2 cups liquid
Old pencil or stick long enough to go over the container
time


what you do

While stirring a cup of boiling water, slowly pour in Epsom Salts, adding about 1/4 cup at a time. It will hold quite a lot. As soon as the solution won't turn clear with stirring, it is time to stop.

Take one or two pretty, colorful pipe cleaners. Bend it into some holiday shape at one end, leaving the other for a "hanger." Hang it over a pencil suspended over a STRAIGHT SIDED container, or you won't be able to get your crystal out. (I learned this one the hard way, obviously.) Pour the Epsom Salt solution over the pipe cleaner in the container. Set it in the warmest room in your home where it won't be disturbed.

In about 3 weeks, the water will have evaporated, leaving long, lovely crystals behind on the pipe cleaner, just in time to hang up as an ornament.

Ok, they may not be ready by then. But still worth doing.

Title: Re: What's your kitchen science?
Post by: paul.fr on 25/06/2007 16:59:46
what you need

One to keep the kids entertained on a gloomy, rainy day...like today.


2 tablespoons (10ml) soap powder or scrapings (not a detergent)
1/4 cup (60ml) hot water
1 tablespoon (5ml) turpentine
spoon


what you do


In a bowl dissolve the soap powder in hot water. Add the turpentine then pour into a small screw top jar.
Brush over a picture like from those from a comic book or magazine. Wait about 10 seconds and place a sheet of paper over it. Rub the back with a spoon. The picture can be transferred to t-shirts, paper, etc. and can usually be transferred more than once.

Obviously, the kids will need to be supervised when handling turpentine
Title: Re: What's your kitchen science?
Post by: paul.fr on 27/06/2007 18:20:03
an early posted wekend activity for the kids, making clay models.

what you need


1 cup rolled oats
2/3 cup flour
1/2 cup water
large bowl

what you do


Mix all of the ingredients in a large bowl.  Add more flour if necessary for the dough to form a lump. knead the dough on a floured surface until it is smooth. You can add food coloring to the water before mixing the dough, or divide it into balls and add the coloring afterwards.

make something!

air dry overnight.

Title: Re: What's your kitchen science?
Post by: paul.fr on 29/06/2007 15:52:06
what you need


scissors
an index card, or piece of card 3" x 5"


what you do


Fold the file card in half lengthwise and make 13 partial cuts widthwise. First cut through the folded side, then turn the card around and cut toward the fold. Keep repeating the process. (Cut to within a quarter inch of the edges of the card.)

Very carefully open the card and cut lengthwise along the fold. Do not cut the two end sections.

Gently stretch the card as far as it will go and put it over your head.
Title: Re: What's your kitchen science?
Post by: paul.fr on 01/07/2007 15:25:54
what you need


12-inch ruler
Several sheets of paper newspaper.
Table


what you do


Lay a 12-inch ruler on the edge of a table so that about a third of the ruler extends over the edge. Place several large sheets of newspaper, over the ruler. Hit the ruler sharply.

What happens? Why?
Title: Re: What's your kitchen science?
Post by: paul.fr on 03/07/2007 07:32:35
what you need


a few different shells
vinegar
an old, empty jar
coarse sandpaper.


what you do


Half fill a jar with vinegar and place a shell in it. Leave it for a day. Before you fish it out, can you see any bubbles coming from it?

Once it is out, examine the shell to see how it has changed.

Using a different shell, rub one side of it against the sandpaper. It's easiest if you place the sandpaper on a hard, flat surface.

Gradually the shell will wear down, layer by layer, revealing the inner structure.

Title: Re: What's your kitchen science?
Post by: paul.fr on 23/07/2007 20:23:13
A variation on a previous post.

What you need

Bowl of cold water
Coin (bigger than the bottle opening)
Glass Bottle (with a small opening/mouth, something like a coke bottle)


what you do


Fill a bowl with some cold water. Place the bottle neck and coin in the bowl of water to chill them.  This helps to make an airtight seal when you place the coin on the top of the bottle.

After a few minutes, remove the bottle and coin. Then place the coin on the top of the bottle, wrap your hands around the bottle and wait for several seconds.

What happens to the coin?

Remove your hands from the bottle and wait.


What happens to the coin now?
Title: Re: What's your kitchen science?
Post by: paul.fr on 23/07/2007 20:44:02
what you need


a long glass jar, like olives come in
water
Paper and a pen


what you do


Wash the jar and remove the label. Fill a large bowl or dish pan with water. Place the jar under the water and turn it so all the air comes out. Still under water, put the lid on the jar.
When you remove it from the water, there should not be any air bubbles inside. Dry the outside of the jar.

Print the following words on a sheet of paper. Print them neatly, just as
they are here. You can always type the words, and print them with your printer.

HIDE MY BIKE

Place the jar over the words, with the side of the jar touching the paper. Reading through the jar, what do you see? You see the same words, maybe a bit bigger depending on your jar, but otherwise just the same.

Lift the jar a couple of inches off the paper, and read the words through the jar again.

What happened to the words?
Title: Re: What's your kitchen science?
Post by: paul.fr on 24/07/2007 15:22:28
what you need


Oil
Sink
Funnel
Vinegar
Paper towels
Blue food coloring
1/2 cup, measuring cup
Small, clear plastic drinking bottle with screw lid


What you do


Remove the top from the clear plastic bottle (keep the lid), and pour out half a cup vinegar into the measuring cup. Add a couple of drops of the blue food colouring into the vinegar.

Place the funnel in the mouth of the bottle and pour the vinegar mixture into the bottle, Swish the bottle around a bit so that the blue food colouring mixes with the vinegar.

Pour out half a cup oil into the measuring cup, place the funnel into the mouth of the bottle and pour the oil into the bottle.

Remove the funnel and screw the lid back onto the bottle (making sure that the lid is secured properly so that there is no leaking). Shake the mixture.

What happens?

Let the mixture sit for a few minutes, and keep watching it.

What happens?

Take the lid off and tip the bottle to pour out a bit of the mixture into the sink. What happens? The oil comes out and the vinegar stays to the bottom of the bottle.

Place your index finger over the top of the bottle and turn it upside down over the sink very slowly, keeping your finger in place.

Now uncover a bit of the opening of the lid and let a little bit of the solution drip out.

What happens this time?

Title: Re: What's your kitchen science?
Post by: paul.fr on 25/07/2007 20:53:47
Not very sciency, but Anastasia enjoyed doing this and it passes some time for bored kids in the holidays.

What you need

Fallen leaf or leaves
Ribbon (about 25cm)
Transparent plastic bag
Permanent ink marker
Small basin
paper towels
Food colouring
Paper punch
Stiff paint brush
Household bleach


What you do


Clean the leaf thoroughly to remove dirt. Soak it in a strong solution of bleach till it turns white. Caution: Strong household bleach is corrosive. Please avoid direct contact with your fingers or skin.
 
Rinse the leaf and gently remove the soft tissue with a paint brush.
 
Rinse and blot dry between paper towels.
 
Pour the food colouring of your choice into a small basin. Dip the leaf skeleton in it. Remove and dry between paper towels.
 
Insert the dyed leaf skeleton into the transparent plastic bag. Use a paper punch to make a hole on the unsealed side of the bag.
 
Put a ribbon through the hole and secure neatly. Label the leaf by writing its common or scientific name on the plastic bag with a marker.
 
And there you have it, you very own unique "leafmark"!

As stated above, do be careful when using household bleach
 
Title: Re: What's your kitchen science?
Post by: paul.fr on 26/07/2007 11:37:31
what you need


Plastic bottle
Baking soda
Vinegar
Drinking straw
Plasticine
Scissors.


what you do


With a pair of scissors, make a small hole in the bottom of the plastic bottle, close to the edge.
 
Push the plastic straw through the hole until only about 1cm sticks out. Press the straw down a little. Press plasticine round it to keep the straw in place and seal up the hole.
 
Shake some baking soda onto a paper tissue or piece of paper. Wrap the paper round the baking soda and twist the ends, like a sweet.
 
Pour some vinegar into the bottle. Push in the paper with the baking soda wrapped inside(through the bottle top). Put the cover of the bottle on as quickly as you can. Put the bottle gently into a bath of water and let go.
 

What happens?
Title: Re: What's your kitchen science?
Post by: paul.fr on 27/07/2007 18:35:43
Ooh, nearly 20,000 views.

what you need

Bucket
Glass bottle
Hammer
Nail
Needle
straw
Plasticine
Food Colouring


what you do


Half fill the bottle with cold water and add food colouring to colour the water then crew the lid on tightly.
 
Using a hammer and a nail, carefully make a hole in the lid of the bottle. The hole must be big enough for the straw to fit in.
 
Push the straw into the hole until it is below the water level. Use the plasticine to seal around the hole of the bottle and the hole of the straw. Make another smaller hole at the top of the straw with a needle.
 
Fill the bucket with hot water and put the bottle in the bucket. What a while...

What happens?
 
Use caution with the hot water and the hammer
Title: Re: What's your kitchen science?
Post by: paul.fr on 01/08/2007 15:25:41
what you need


Small rubber ball
Flat table top surface
Medium size jar with a wide mouth

what you do


Place the ball on top of the table and put the jar over the ball so that the ball is inside the mouth of the jar.

Start spinning the jar around in a circular motion (keeping it on the table).

Once the ball starts spinning inside the jar lift it from the table top.

What happens?
Title: Re: What's your kitchen science?
Post by: paul.fr on 06/08/2007 21:55:26
what you nedd

Two beakers
Muddy water
A strip of cloth


what you do

Fill one of the beakers with the muddy water, and leave the other empty. Place the strip of cloth so one end is in each beaker.
Leave, undisturbed overnight.

What happens?

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi154.photobucket.com%2Falbums%2Fs262%2Fpf0604%2FImage013.jpg&hash=a0339d69f83a9bab80f80f8d3f50f99e)

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi154.photobucket.com%2Falbums%2Fs262%2Fpf0604%2FImage014-1.jpg&hash=ab00cd802a3581c9c3c8e818f1ab9215)
Title: Re: What's your kitchen science?
Post by: paul.fr on 06/08/2007 22:07:44
Just a reminder that there is an rss feed, for the excellent Kitchen Science section of the main Naked Scientist site? These are the experiments that are conducted on the show.

This is the url for the rss feed: http://www.thenakedscientists.com/rss/kitchen_science.xml


Alternitavley, if you use widgets / widsets on your internet enabled phone. Like the hundreds of other users, you can download a widget from this link.
http://www.widsets.com/widgets?publicwidgetid=W2222   (https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi154.photobucket.com%2Falbums%2Fs262%2Fpf0604%2Fexperiment.png&hash=d46906fc1acbe9ae3c517ca1ddd1abbe)   (https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi154.photobucket.com%2Falbums%2Fs262%2Fpf0604%2Flarge.gif&hash=c601218ae2856cac69898ed7aeaa840c)


If the above link does not take you to the specific widget, just type kitchen science in to the search bar.

RSS (Really Simple Syndication) provides a convenient way to syndicate information from a variety of sources, including news stories, updates to a web site or basically any type of publication. Regardless of the purpose for which the RSS file is being used, by watching this XML file, you can quickly and easily see whenever an update has occurred.

You can use the rss feed in you "home page", if you use yahoo or msn for example.

Don't forget to visit the Main kitchen Science Section, on the Naked Scientist, for the latest experiments from the show.
http://www.thenakedscientists.com/HTML/content/kitchenscience/





Title: Re: What's your kitchen science?
Post by: paul.fr on 08/08/2007 00:25:51
Make you own "bath bombs"

what you need

2 cups of baking soda
1 cup of cornstarch
1 cup of citric acid
A large and a small mixing bowl
and a few drops of food coloring


what you do


Place all of the ingrediants in a large bowland mix well, scoop out 1 cup into a small bowl and add the coloring.

Mix well again, then add this back to the large bowl and mix well....

Remove enough mixture to the small bowl for one bomb and mist lightly with a spritz bottle, just enough to hold salts together. DON"T over mist , this is where technique comes in . Press the moisten mixture into a mold,pack down hard. Continue on in the same way. If your molded bombs break , just moisten and remold. If you have added to much water just add more dry ingredients to stop the fizzing.

Carefully remove the bomb from the mold and let dry out overnight. You can use anything to make your mould, ice cube trays old containers...anything.

Note: If you want fragrant bath bombs, just add 30 to 40 drops of a fragrant oil at the initial mixing stage.



Title: Re: What's your kitchen science?
Post by: i am bored on 09/08/2007 02:16:39
speaking of bombs can you take a look at this for me http://www.thenakedscientists.com/forum/index.php?topic=9348.msg113569#new (http://www.thenakedscientists.com/forum/index.php?topic=9348.msg113569#new)
Title: Re: What's your kitchen science?
Post by: paul.fr on 11/08/2007 15:29:13
what you need


blu-tack
string
sun glasses
a window


what you do

Roll 2 small balls with the blu-tack, about 1cm in diameter. Stick one of the balls on each end of your string, and attach one of them to the middle, top of the window frame.

You should now have a length of string, hanging from the window frame with a ball of blu-tack on the other end.

Set the string swinging from side to side. Retreat to the other side of the room, and put your sunglasses on.

With your sunglasses on, and the string swinging from side to side. Close your left eye whilst looking at the ball of blu-tack swinging on the string.

what happens?

Now close your right eye, looking with your left.

What happens?
Title: Re: What's your kitchen science?
Post by: paul.fr on 12/08/2007 12:22:09
Make the bst bubbles, for blowing.

What you need

Sugar
washing up liquid
Hand / shower gel (must contain glycerin, check label for ingredients)

What you do


Dissolve the three tablespoons of white sugar in 100ml of hot water, and stir well. Stir in a desert spoon of washing up liquid. Then stir in a tablespoon of clear hand gel.

Go blow bubbles.
Title: Re: What's your kitchen science?
Post by: paul.fr on 12/08/2007 12:22:16
what you need


A smarties type tube
A sharp pencil
blu-tack
String
Scissors
A ruler
Tissue paper
Some of the bubble mixture from the previous post.


What you do

Seperate the layers of tissue paper, and cut a thin strip off one layer about 2cm wdie. Tie one end of the string to the top of your srtip of tissue paper.

Affix the blu-tack to the other end of the string and hang it from a shelf or window frame. You now have the strip of tissue paper suspended from the string.

With the pencil, make a hole in the end of the smarties tube. The hole should be only about 0.5cm wide.

Put the open end of the tube in your bubble mix, and give it a gentle stir. Gently blow through the end you poked a hole in to make a bubble, do not blow too hard, you want the bubble to remain on the end of the tube.

Put the end of your tube with the small hole in it close to the hanging tissue paper.

what happens?
Title: Re: What's your kitchen science?
Post by: paul.fr on 14/08/2007 16:03:19
what you need

2 ice bube trays
water
a freezer


what you do


Get both ice trays and fill one with tap water, and the other with boiled water. Put them both in the freezer and let them freeze.

what happens?
Title: Re: What's your kitchen science?
Post by: neilep on 14/08/2007 19:21:47
What You Need

Participatory Members !!



What You Do


Try to add to this fantastic thread as much as you can with your own kitchen science experiments and fun things to do !!
Title: Re: What's your kitchen science?
Post by: paul.fr on 15/08/2007 13:39:51
what you need


A jam jar
blue mouthwash
olive oil


what you do


pour enough mouthwash to fill the jar to a depth of 5cm, then pour in a layer of olive oil to a depth of 0.5cm. Replace the lid and shake the jar.

Both substances should now mixed.

Hold the jar up to a strong light, what do you notice about the liquid?

Edit: if you don't have blue mouthwash, you can use water with atleast 3 drops of blue food colouring in at, as a substitute.
Title: Re: What's your kitchen science?
Post by: paul.fr on 18/08/2007 15:48:15
what you need

your nose
a hand


what you do


beigin humming, then suddenly pinch your nostrils together.

what happens?
Title: Re: What's your kitchen science?
Post by: Karen W. on 20/08/2007 00:58:14
Wow.. Cool pinch first and try to hum! Very weird.. I have never noticed that before! LOL
Title: Re: What's your kitchen science?
Post by: paul.fr on 20/08/2007 16:13:26
what you need

3 bowls
water
watch / clock


what you do

Fill the three bowls, one with hot water from the tap, one with cold water and the other with tepid water.

put one hand in the cold water and the other in the hot water, leave them there  for 45 seconds and remove. Your hand may ache in the cold water but it will do no harm.

Now put both hand in to the tepid water, what do you notice about the temperature of your hands?

Where i state to use hot water from the tap, this should not be red hot. Just to a degree of "hotness" (is that a word) that is comfortable

This was also done on the show http://www.thenakedscientists.com/HTML/content/kitchenscience/exp/how-to-fool-your-senses/ [dave]
Title: Re: What's your kitchen science?
Post by: paul.fr on 22/08/2007 19:25:33
what you need

a piece of shiny, metallic card
scissors


what you do


cut a piece of the card 30cm long and 9 cm high, and cut a semi-circle out in the middle. this is where the card will sit on your nose.

sit the card on your nose, with the shiney side facing your eyes. Now bend both ends of the card slightly away from your face.

what happens?

if you don't have shiny metallic card you could always use ordinary card and stick kitchen foil on to it.

Title: Re: What's your kitchen science?
Post by: paul.fr on 27/08/2007 13:53:12
A variation of how we used to play naughts and crosses at school, paper was expensive back then!

what you need


your arm
a finger nail


what you do


scratch a word on the underside of your forearm with your finger nail, but don't break your skin. In a few moments the word will appear in the form of white marks.

Now rub the area of your skin where the word is.
what happens?
Title: Re: What's your kitchen science?
Post by: paul.fr on 27/08/2007 14:00:22
what you need


a darkened room with white or light coloured walls.
a small, bright torch


what you do


stand about 2 foot from the wall, and face it. with the torch at just below the level of your chin and just beyond the end of your nose, turn the torch on. The beam should be slightly turned twoards your eyes not shone directly in to your eyes. Wait a few seconds, what do you notice? what are you seeing?
Title: Re: What's your kitchen science?
Post by: paul.fr on 02/09/2007 05:59:33
what you need

a large lid, or circular disc
pencil
paint
large sheet of white paper
blu-tack


what you do

Draw around the lid to make two circles, side by side. Paint one circle a dark colour and the other a light colour. Allow it to dry and hang the paper on a wall with the blu-tack.

Stand a few feet back, and look at both circle.

What happens?
Title: Re: What's your kitchen science?
Post by: Andrew K Fletcher on 05/09/2007 10:01:10
Experiments showing a simple flow and return circulation driven by gravity, yet powerful enough to raise water effortlessly to great heights.

What you need

Some salt, sugar, food colouring, plastic tube 4 metres, (type used to oxygenate fish tanks) T connector to join tubes, Syringe body (without needle end) to inject salt solution (can be scrounged from local vet or doctor) tray to catch water, clear vase or tall glass,  two clear glass small bottles, a little stiff wire or some tape to hold the tubes in the two bottles,

What to do:

Is shown in the video, so watch the video for further instructions
I will be posting the experiment results showing the desired effect but it would be cool if you could have a go yourselves and report the results here. Once your experiment is ready to go, elevate the centre of the tube which has the syringe body filled with coloured saline sollution attached and observe what happens.

Andrew



In this short video there is an example of water exuding from an open ended U tube showing precisely how water exudes from a cut stem. When viewing the part about spirit levels and while observing the level differences between the tube, picture a pair of scissors cutting through both tubes as would be the case in a tree or plant. What would happen to the water levels?

Andrew
Title: Re: What's your kitchen science?
Post by: paul.fr on 09/09/2007 12:22:06
what you need

a potatoe
a strong straw


what you do

Hold the straw firmly but without crushing or bending it. Hold the potato in the fingertips of your other hand, take aim and stab the potato with the straw as hard as you can!

what happened?

if nothing happened, or the straw just bent, then you were possibly a bit nervous, just pretend the straw is as rigid as a pencil and stab the potato harder.

for added safety, you may want to wear a gardening type glove on the hand that is holding the potatoe
Title: Re: What's your kitchen science?
Post by: paul.fr on 16/09/2007 09:43:55
what you need

A football (or basketball)
A tennis ball


what you do


with the football held out straigh in your hands, drop the ball and see how high it bounces. Now repeat with the tennis ball. Note that how how they bounce when dropped individually.

Now hold the two balls so that the tennis ball one is resting and centred on top of the football, rop the two balls drop simultaneously.

what happens?
Title: Re: What's your kitchen science?
Post by: paul.fr on 21/09/2007 14:53:29
what you need

A straw
A pair of scissors


what you do


cut a point in the end of a straw, so it’s shaped like a flat pencil and flatten it out between your teeth. put the flattened pointy end in your mouth, press down with your lips and blow. you should get a buzzy trumpet sound.

Take a big breath and gently blow down the straw, as you blow cut bits off the end of the straw.

What happens to the "tune"?
Title: Re: What's your kitchen science?
Post by: neilep on 30/09/2007 21:21:51


What you need !

One arm !
 [ Invalid Attachment ]

What you do !


Press the whole arm against the wall for a minute then walk away.

What happens ?


Ewe can try this with a leg too !!...preferably your own !!
Title: Re: What's your kitchen science?
Post by: techmind on 05/10/2007 00:06:39
what you need

An empty 500ml soft-drink bottle
Kettle + boiling water  (need supervision for youngsters)

what you do

Stand the empty bottle (with the lid removed) upright in a sink.

Boil the kettle. Pour the boiling water into the neck of the bottle.
The water needs to be very hot, so start pouring as soon as the kettle has switched itself off.
You need to be careful when you start to pour the water that you don't topple the bottle over. It's also slightly harder than you might imagine, as you will find out. See if you can fill the bottle completely.


It works with some mineral water bottles, and some clear washing-up bottles too (basically any PET-type plastic bottles).

CAUTION: don't pick up the bottle too soon - it will remain hot!
If you're impatient, when you're done knock the bottle over with a spoon, let it empty down the sink, and splash with cold water :-)
Title: Re: What's your kitchen science?
Post by: techmind on 05/10/2007 00:26:55
Related to the above... (but different outcome)

what you need

An old/expired/unwanted "credit card"-type plastic card.
Kettle + boiling water  (need supervision for youngsters)
A large mug, or soup-bowl
A desert-spoon

You can use any similar plastic card such as a cashpoint/debit card, an AA membership card, or a mobile-phone top-up card. It should be the type of card that has raised lettering.
You will not be able to use the card after this experiment, so please use an unwanted card!!!


what you do

Put the plastic card into the mug or bowl.

Boil the kettle.

Pour the boiling water over the plastic card.
The water needs to be fairly hot, so start pouring as soon as the kettle has switched itself off.

Fish out the plastic card using the spoon. Oooohhhhh!


Repeat until bored!

Note it stops working as the water cools, so you may need to boil some more water :-)
I guess you could also do this experiment in a small saucepan on the hob.


P.S. I discovered this myself one evening when I had a small stash of cards to get rid of...
Title: Re: What's your kitchen science?
Post by: techmind on 05/10/2007 01:01:09
What you need

Small portable AM medium-wave / long-wave radio
Digital electronic gadgets (suggest TV remote control, MP3 player, digital watch or alarm clock)

What you do

Switch on the radio, and set it to MEDIUM WAVE or LONG WAVE.
This experiment will not work on VHF/FM.

Tune the radio to a quiet spot between any stations.
If you hear a lot of loud and nasty buzzes and whistles then ensure the radio is moved well away from any computers/consoles, and that nearby fluorescent lights and "energy-saver" lightbulbs are switched off.
Turn up the radio volume to maximum.
You may hear a little bit of hiss and some crackles or some feint whistles or foreign stations. That's okay. It's best to find the quietest position of the tuning that you can, however. The internal ferrite rod aerial is directional, so you can also try rotating the radio to make the background as quiet as possible.

Now place your TV remote control very close to the radio. Press a button on the remote.
Did it make you jump??!!
Now try pressing different buttons on the remote.

Now try placing other digital gadgets close to the radio, e.g. a (plastic-cased) digital watch, alarm clock, or an MP3 player.
You might find the effect is rather quieter (especially with the digital watch), so you may have to move the test-item around the case of the radio to find the most sensitive spot (which will be somewhere near the ferrite rod aerial inside).

With the watch or clock, you might find the sound changes as the seconds tick over.
With the MP3 player try playing a song, and skipping forwards or backwards tracks while listening to the radio.


Now for the really clever bit: place a mobile phone close to the radio. Start with the phone completely switched off, then switch it on while it's very close to the radio. After it's all settled down, try making a brief phone call (maybe to your balence enquiry/voicemail/or other free info service). Hang up. Again after it's settled down, try switching off the phone completely. There will probably be a mixture of very loud and much quieter subtle effects. You may have heard the loud ones in the past (you even get the loud ones on VHF/FM radios). Listen carefully even when the phone is switched on but apparently doing nothing (you may need to slowly and carefully move the phone around the case of the radio to find the best spot to hear this).
[I can explain what some of these are in a future posting]

This can be even more interesting to do if you're travelling longer distances (not driving) in a car or train and have a radio and phone with you. (It won't work with the car radio - you need a small portable/personal radio; earphones are fine). You don't need to make any calls - just leave the phone switched on and held next to the radio. You may have heard the loud sound on the FM band before too - but you need the medium/long wave band to hear some of the more subtle stuff. See what happens when you go into a tunnel or an area with poor mobile reception...


The radio is like a stethoscope diagnosis-tool for digital gadgets!
Title: Re: What's your kitchen science?
Post by: techmind on 05/10/2007 14:22:19
What you need

LCD computer screen (to use as a light source)
Polaroid / polarizing sunglasses
Some clear plastic objects - the lid of a CD case works very well. If you're careful then your CD case won't get damaged, but it might be safer to use one you don't care about too much.
Some Sellotape (transparent self-adhesive tape, Scotch tape etc)

This experiment will ONLY work with LCD screens. It won't work with older cathode ray tube screens. Sorry.
As this experiment probes effects of polarised light, it will only work with polarising sunglasses.


What you do

It's not essential, but you may need to dim the lights in the room a bit for best effect.

You need a mostly-white screen on the computer, so fire up a Notepad or Wordpad (or equivalent program) and maximise them to full screen so you have a good uninterrupted expanse of white.


Part 1

Put on the sunglasses. You will probably find that the room gets a bit darker, but the screen doesn't get much dimmer. Now turn your head on its side. What happens?
You might find it easier to take the sunglasses off and rotate them in front of your eyes instead.
If nothing much happens then probably the sunglasses aren't polarizing. Try and find another pair.


Part 2

Adjust the angle of the sunglasses to make the screen darkest.
Now hold the lid of your CD case in front of the screen. Wow!

Try with a plastic lunchbox, plastic packaging, plastic ruler, plastic business-card box, etc


Part 3

Cut or tear some strips of sellotape and stick them randomly on the lid of the CD case so they are criss-crossing each other.
Have another look in front of the LCD screen with the sunglasses.
You could even make specially cut pieces of sellotape to make a picture (you might find that other plastics - like overhead projector transparency - give a better plain dark background).
You could also try just sticking some short lengths of sticky tape randomly on top of each other and holding the sticky patch in front of the screen. (Be careful not to let the tape stick to your screen though, as you could damage the coatings.)
Title: Re: What's your kitchen science?
Post by: techmind on 05/10/2007 14:44:26
What you need

Paper or plastic disposable cup  (paper cup will probably be a bit easier)
'Bendy' drinking straw
You might also need a bit of blu-tak or plasticine
Scissors (adult help), a skewer (adult help), or a single-hole office hole-punch may be useful too.


What you do

Make a hole in the cup, ideally that's a good fit for the straw, about half an inch (a centimetre or just over) from the top of the cup.

Thread the straw through the hole so that the bendy section sits in the hole, and the short end of the bendy-straw is inside the cup and pointing down.
(You could use a waterproof elastoplast or some waterproof glue to stick the straw to the inside of the cup if necessary.)
If the straw is not a very good fit in the hole, then use some plasticine or blu-tak to make a reasonable seal - it doesn't need to be perfect.
Hold or tape the part of the straw that is outside the cup so it is pointing downwards, and the bottom of the straw is below the bottom of the cup.

(Make sure the straw is not squashed flat anywhere)

Fill the cup with water to a level about a centimetre below the level of the hole you made.

Get someone else to hold the cup for you, or balence it on the edge of the sink/draining board.

Now slowly pour in some more water (a second cup may be useful).
(If the hole leaks too much then you may need to pour a bit faster).

What happens?
Title: Re: What's your kitchen science?
Post by: paul.fr on 14/10/2007 12:05:31
what you need

a sunny day (could be hard in the UK right now)
a shallow glass baking dish
a mirror
water
white paper or cardboard
an assistant


what you do

Put the glass baking dish flat on the ground or a table., and put the mirror in the dish. Lean the mirror up against one side.

Turn the dish so the mirror faces the sun and add water until the dish is about half full.

Have the helper hold up the paper at the end of the dish away from the mirror and move it around slowly. Watch for the sunlight bouncing off the mirror.

What happened?

Topic link: Can i make a rainbow at home
http://www.thenakedscientists.com/forum/index.php?topic=10798.0
Title: Re: What's your kitchen science?
Post by: Bass on 16/10/2007 04:41:40
Everyone is fascinated with volcanos- and almost all of us have seen the model volcanos erupting with vinegar-baking soda-food coloring.
For different type of volcano model that shows how craters (calderas) form here's an easy demonstration:

Get a box, at least 2 feet (65 cm) square, and seal the inside bottom with tape (otherwise you end up with flour on the floor).  Punch a small hole in the bottom, and stick a bit of tubing through the hole.  Attach the tubing inside the box to a small ballon (rubber bands work well).  Inflate the balloon, then build a mountain of flour (or some other fine grained material) on top of and around the balloon (but all contained in the box).  Slowly release the air from the balloon, and the collapse crater will form on the top of the flour "mountain".  Varying the rate of balloon deflation will change the pattern of the crater.
Another suggestion was to use different colored layers of flour to better demonstrate what happens during collapse.
Title: Re: What's your kitchen science?
Post by: paul.fr on 16/10/2007 15:08:02
Excellent. Thanks for the contribution, Bass.
Title: Re: What's your kitchen science?
Post by: paul.fr on 25/10/2007 22:28:47
what you need

a balloon
a hexagonal nut without any sharp edges


what you do

pop the nut into the balloon and inflate it, tie the balloon off, and whilst holding it move the balloon in such a way that the nut rolls around inside.

do not hold the balloon tight in both hands, just a light grip from two fingers off each hand will do.

what happens?
Title: Re: What's your kitchen science?
Post by: paul.fr on 25/10/2007 22:42:00
what you need

a candle that's the same width all the way down
matches
two glasses that are the same height
a darning needle
a knife
a room without a breeze
an adult to help you with the knife, the needle & the matches

what you do

cut the bottom 1cm off the candle so the wick is exposed, and poke the darning needle through the middle of the candle (the closer to the middle you are, the better it'll work).
put your two glasses upside down and balance the ends of the needle on them, so the candle can swing through between them.
make sure the candle is balanced, and then light one end and then the other.

wait...what happens?

with a knife and matches used in this experiment, child supervision is essential.
Title: Re: What's your kitchen science?
Post by: techmind on 27/10/2007 00:50:45
Neat video:

What you need
A flat-headed screw, 3 to 6cm long
Small, fairly strong round (disc) magnet
20cm of wire
'D' or 'C' cell ALKALINE battery  Do NOT try a rechargeable battery as this would be very dangerous

What you do
Stick the magnet onto the head of the screw
This should magnetise the screw sufficiently that you can hang the pointy end of the screw from the underside of the battery (see video)
Hold one end of the wire to make contact with the top end of the battery
Tickle the other end of the wire on the magnet or screwhead

Caution: Don't hold the wire connected to the screwhead for more than a few seconds as you are effectively short-circuiting the battery - you'll flatten the battery quite quickly and it could even get hot.

Caution: Absolutely DO NOT attempt to use any kind of rechargeable battery (NiCd or NiMH etc) as owing to their much lower internal resistance a very large current will flow, probably enough to melt the wire... at the least you'll burn your fingers, at the worse the battery could explode


It's too late at night for me to figure/explain why it works in detail, but it's all to do with the magnetic field around current-carrying conductors. I'm sure it's much the same explanation as an old experiment where you have a suspended wire dipping in a dish of mercury (probably banned these days!)

If you reverse the battery OR the magnet, the direction of rotation should change.
Title: Re: What's your kitchen science?
Post by: paul.fr on 28/10/2007 18:52:11
what you need

a clear jar or vase with a wide opening
baking soda, or bicarbonate of soda
vinegar
bubble mix and a bubble ring


what you do


put a few spoons full of baking soda in the jar and pour in some vinegar so it bubbles about halfway up the jar.

when the bubbles settle down a bit, swirl the mixture around to help the baking soda dissolve, then blow some bubbles up nice and high, and catch one in the jar.

what happens to the bubble you caught in the jar?
Title: Re: What's your kitchen science?
Post by: paul.fr on 28/10/2007 18:59:43
what you need


2 balloons
a piece of rubber hose about 15cm long and wide enough for the balloon mouth to fit around snugly
someone to help you hold the balloons


what you do


blow one of the balloons up to normal size, and get your friend to hold the neck of it tightly while you blow the other one up to half that size

don't tie the balloons off!

put the mouth of the balloons onto the ends of the rubber tubing without letting too much air escape, and without letting go of the neck of the balloon. once both balloons are attached to the tubing, let go of their necks at the same time

what happens!
Title: Re: What's your kitchen science?
Post by: paul.fr on 03/11/2007 21:47:04
what you need

a marble
a bendy straw


what you do


bend your straw into an L shape and then put the straw in your mouth, so the short bit sticks up like a pipe.
hold the straw in place and balance your marble on the end of the straw, nowblow through the straw.

what happens!
Title: Re: What's your kitchen science?
Post by: paul.fr on 03/11/2007 21:53:58
what you need

coloured water, cordial, cola...any liquid with a colour
glass
2 straws


what you do

Fill the glass with your chosen liquid, and put one of the straws in and hold it up straight Don't let the straw rest on the bottom of the glass. Now, hold the other straw so the end of it touches the top of the first straw and blow!

what happens?
Title: Re: What's your kitchen science?
Post by: daveshorts on 04/11/2007 12:24:48
If you want an explanation for the floating marble one has certain similarities to:
http://www.thenakedscientists.com/HTML/kitchen-science/in-lab/exp/the-aerodynamics-of-a-ping-pong-ball/
Title: Re: What's your kitchen science?
Post by: paul.fr on 11/11/2007 19:08:39
Make a square bubble.

what you need

pipe cleaners
bubble mixture


what you do

use the pipe cleaners to make a 3D square, and dip it in to your bubble mixture. you may get some extra round bubbles, these can be easily popped to leave a nice square bubble.

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi154.photobucket.com%2Falbums%2Fs262%2Fpf0604%2Fsqb.jpg&hash=193ff22fe523e96432f6149b24a37a28)

why does it do that?
when one bubble is surrounded by other bubbles, it can make stable shapes with corners and sides. Try making a 3D triangle...go on..
Title: Re: What's your kitchen science?
Post by: paul.fr on 18/11/2007 11:41:37
what you need

a bank note
2 paper clips

what you do

fold the note in to a "s" shape, and attach the paper clips where the "o"s are in this very bad diagram
[diagram=290_0]

holding the sides of the note, gently pull to straighten the note out.
what happens to the paperclips?
Title: Re: What's your kitchen science?
Post by: paul.fr on 18/11/2007 11:52:22
what you need

two coins of the same value

what you do

place one coin in each hand, as shown in the pretty poor diagrams.

left hand.
[diagram=291_0]

right hand.
[diagram=292_0]

yes, they are the worst diagrams you have ever seen....any way. the coin in your right hand should be in the middle of your palm, and the coin in your left hand needs to be close to your thumb..this is obvious in the diagrams!

now turn your hands so they are palm down, where are the coins?


*****can anyone do better diagrams? if you can please feel free to edit mine...please

whats happening

rotational mechanics

When you turn your hands over you're rotating them around their centre point, which is near the middle of your palm. The coin in the middle of your hand will just drop straight down, so it'll stay under that hand. But the coin out near your thumb gets rotated around the centre point of your hand, and that flicks it over under your other hand.
Title: Re: What's your kitchen science?
Post by: paul.fr on 12/01/2008 16:52:30
In honour of this weeks, Question of the Week - How do Boomerangs Work? (http://www.thenakedscientists.com/forum/index.php?topic=12296.0)

What you need

cardboard or thick paper
a pen or pencil
scissors

What you do

draw a cross shape (like two plasters overlapping to form a cross), and cut it out. slightly bend all four ends in the same upwards direction.

Place your 'boomerang', slightly over the edge of a table and flick it.
Title: Re: What's your kitchen science?
Post by: Karen W. on 12/01/2008 17:07:31
what you need

two coins of the same value

what you do

place one coin in each hand, as shown in the pretty poor diagrams.

left hand.
[diagram=291_0]

right hand.
[diagram=292_0]

yes, they are the worst diagrams you have ever seen....any way. the coin in your right hand should be in the middle of your palm, and the coin in your left hand needs to be close to your thumb..this is obvious in the diagrams!

now turn your hands so they are palm down, where are the coins?


*****can anyone do better diagrams? if you can please feel free to edit mine...please

whats happening

rotational mechanics

When you turn your hands over you're rotating them around their centre point, which is near the middle of your palm. The coin in the middle of your hand will just drop straight down, so it'll stay under that hand. But the coin out near your thumb gets rotated around the centre point of your hand, and that flicks it over under your other hand.

Yes your thumbs are on the wrong hands! Cool experiment.. I will try it!
Title: Re: What's your kitchen science?
Post by: Karen W. on 12/01/2008 17:16:51
what you need

two coins of the same value

what you do

place one coin in each hand, as shown in the pretty poor diagrams.

left hand.
[diagram=291_0]

right hand.
[diagram=292_0]

yes, they are the worst diagrams you have ever seen....any way. the coin in your right hand should be in the middle of your palm, and the coin in your left hand needs to be close to your thumb..this is obvious in the diagrams!

now turn your hands so they are palm down, where are the coins?


*****can anyone do better diagrams? if you can please feel free to edit mine...please

whats happening

rotational mechanics

When you turn your hands over you're rotating them around their centre point, which is near the middle of your palm. The coin in the middle of your hand will just drop straight down, so it'll stay under that hand. But the coin out near your thumb gets rotated around the centre point of your hand, and that flicks it over under your other hand.

 ok I tried it, the right hand was definitely as you stated but the left coin did not end up under my other hand.. it ended up right at the outer extension of my left thumb as if my thumb was an arrow pointing to it Right at the tip of my left thumb, but not under my hand!

I was careful to place the coin close to my left thumb and the other in the center of right palm!
Title: Re: What's your kitchen science?
Post by: paul.fr on 22/01/2008 16:07:43
what you need

A hand


what you do

Bend your middle finger and place the centre section on a table or hard surface. You will be able to lift your thumb, index, and little finger without moving your middle finger. But can you lift your ring finger?

 [ Invalid Attachment ]
Title: Re: What's your kitchen science?
Post by: paul.fr on 22/01/2008 16:10:57
what you need

A hand
A foot / leg


what you do

Lift your right foot a few inches from the floor and then begin to move it in a clockwise direction. While you're doing this, use your right index finger to draw a number 6 in the air. What happens to the direction you are turning you foot?
Title: Re: What's your kitchen science?
Post by: paul.fr on 24/01/2008 13:36:26
what you need

2 iron nails
2 glasses (small wine or sherry glasses are ideal)
cooled water (boil a kettle of water then allow the water to cool until it is just warm)
Olive or sunflower oil
Wire wool / fine sandpaper

what you do

Clean each of the nails with wire wool or fine sandpaper. Fill the two of the glasses with cooled water, enough to cover the nail, but leaving a fingers depth unfilled. Add a nail to each of the glasses, and then pour a layer of oil over the water in one of the glasses. The oil will float to the top of the water and form a separate layer which should be about 1cm thick. Leave somewhere where they will not get knocked for 24 hours.

 [ Invalid Attachment ]

What happens to the nails?
Title: Re: What's your kitchen science?
Post by: Cameron Lapworth on 31/01/2008 01:54:50
This is an oldie but a goodie,

What you need a shallow dish with a flat bottom
a candle
a glass
matches
water.

1.attach the candle to the middle of the dish it will need to hold a certain amount of water so not too flat, a bowl with a flat bottom is ideal.

2. pour a couple of centimeters of water in the dish/bowl and light the candle

3.  put the glass over the candle (candle may need to be cut short to fit, don't use a tea candle).

If you want some sense of mystery don't read below

****************************************

what happens:  as the candle burns the air the volume is reduced inside the glass which is now sealed with the puddle of water in the bottom.  This sucks water from around the bowl/dish up into the glass until the pressure is equaled.
Title: Re: What's your kitchen science?
Post by: paul.fr on 31/01/2008 13:05:33
Excellent, Thank you Cameron. Now if the other 6,700 members could post one, just one, what a topic this would be.

what you need

Food colouring
A small jar, or Glass
A larger jar or glass
Aluminium Foil
Rubber Band or Selotape


what you do

Put cold water into the small glass or jar and add 5 drops or so of food coloring. Cover the mouth of the jar with aluminum foil and fasten it in place with a rubber band or tape. Use a pencil point to make a hole at the center of the foil. The hole should be 1/8 inch or so in diameter.
 
Fill a larger jar with warm water. Turn the small jar over and place the foil covered mouth just below the surface of the warm water. Tap on the bottom of the small jar. A ring of colored water will (should) travel downward through the warm water.

If you have a tall vase, then try substituting the larger jar for the vase. This will increase the time before the coloured ring hits the bottom, plus you can make a larger hole in the aluminium foil. Larger holes produce faster moving rings that quickly hit the jar's bottom.
 
Note: A dark coloured water soluble paint can be mixed with the water instead of food coloring.

Pictures to follow at the weekend...
Title: Re: What's your kitchen science?
Post by: paul.fr on 15/02/2008 16:58:47
Here is one from the magazine Popular Science, attributed to chemist Tryggvi Emilsson

What you need


Microscope slide
Cover slip
Super glue
A sheet of black card
small artist's paint brush
Snow!



What you do


Go outside with some glass microscope slides, cover slips, and superglue (not the gel kind; it should be thin and watery).  Cover the slides and cover slips until they become as cold as the surrounding air. 

Let snow crystals fall onto a cardboard collection board, and scan around with a magnifier to find an attractive specimen.  Carefully pick the crystal up using a small artist's paintbrush and place it on one of the slides.


Place a drop of cold superglue on the crystal, and drop a cover slip on top.  Be careful not to melt or otherwise damage the snow crystal in the process.

Leave the slide outside or in your freezer for a week or two until the glue hardens.

Here is a picture of a snowflake using the above method. As you can see, there are some air bubbles, but practice does make better slides.

 [ Invalid Attachment ]

Alternative Method

Another method uses clear acrylic spray paint, which is readily available in hardware stores. The spray is especially effective for replicating windowpane frost and similar ice structures. The (cold) spray must be applied lightly, since the solvent in the spray can dissolve the ice if too much liquid is present.  The best procedure is to pre-coat the glass slide with the plastic film, place snow crystals on it, and then spray the surface again until the surface is moist.   The picture below is from Walter Tape, and was obtained by spraying over a crystal that was placed on a glass slide.

Topic Link:
How Do They Photograph Snowflakes ? (http://www.thenakedscientists.com/forum/index.php?topic=12998.0)
Title: Re: What's your kitchen science?
Post by: paul.fr on 15/02/2008 20:58:26
Is you area affected by acid rain? Lets find out...

What you need



2 finely chopped red cabbage leaves
distilled water
rainwater
a bowl
2 glass jars
a measuring jug
a sieve



What you do
 
Place the chopped cabbage leaves into the bowl and pour hot distilled water over them, let it stand for an hour. Use the sieve to strain the liquid from the cabbage leaves into a measuring jug. It should be a dark purple colour.
 
Pour 20ml of distilled water into one of the glass jars and 20ml of rainwater into the other, add some of the cabbage juice into the two jars making sure you put the same amount in each. The water will then change colour.
 
 
How does the colour of the water in the two jars compare? You should find that the distilled water stays the same, whereas the rainwater may change colour. It will turn red if the rainwater is acidic; the stronger the acid, the redder the water will become.
 
Title: Re: What's your kitchen science?
Post by: paul.fr on 16/02/2008 14:51:34
What you need

A clear plastic container (size of shoebox)
red food coloring
ice cubes made with blue food coloring



What you do



Fill the plastic container two thirds full with lukewarm water, add a few drops of red food colouring and let the water sit for a minute or two.

Place a blue ice cube at one end of the plastic container.
Watch... what happens?


Explanation:

This is how a thunderstorm occurs. The blue and cold water sinks while the red and warm water rises. This happens because of convection. The blue water represents the cold air mass and the red water represents the warm, unstable air mass. A thunderstorm is caused by unstable air and convection plays an important part. A body of warm air is forced to rise by an approaching cold front therefore thunderstorm's form.

Title: Re: What's your kitchen science?
Post by: paul.fr on 16/02/2008 15:21:17
What you need


2 tin cans with the labels removed (soup, baked beans etc...)
rock or table salt
crushed ice (or crushed, regular ice cubes)


What you do


Half fill one of the cans with the crushed ice, and add about 4 tablespoons of salt. Mix it well for about 30 seconds and then let sit.


In the other can put only crushed ice and cool tap water. Fill the can about half way full of ice and then put just enough tap water in the can to cover the ice.


Wait...

What happens?



Explanation:

you should notice frost forming on the outside of the can with the ice and salt mixture. Compare this with the liquid moisture on the outside of the can which contains ice only.


This is how both frost and dew form.

The salt wants to absorb water to make a salt solution. To do that, the salt has to melt the ice into water, melting the ice actually makes the mixture cooler. The salt water mixture inside the can gets below freezing, so the moisture from the air that collects on the outside of the can will freeze. This is why frost forms.
On the other can, dew forms because the mixture of the melting ice and water is just at freezing and the temperature outside the can is warmer causing the dew to form.

You can do this using two glasses, but the effect may not be as noticeable. You may also want to do this using ice cubes, that you have made, that have had food dye added to colour them.
Is the dew or frost that form the colour of the ice cubes, or is it white/clear?
Title: Re: What's your kitchen science?
Post by: paul.fr on 17/02/2008 18:29:15
What you need

glass jar
plate
hot water
ice cubes


What you do


Pour about two inches of very hot water into the glass jar. Cover the jar with the plate and wait a few minutes.

Now put the ice cubes on the plate.

What happens?


Explanation:


This is how rain is made!
The cold plate causes the moisture in the warm air, which is inside the jar, to condense and form water droplets. This is the same thing that happens in the atmosphere. Warm, moist air rises and meets colder air high in the atmosphere. The water vapor condenses and forms precipitation that falls to the ground.
Title: Re: What's your kitchen science?
Post by: DoctorBeaver on 18/02/2008 08:26:46
What you need

a nylon comb
a water tap (faucet in the U.S.)

What to do

Adjust the tap so that it produces a small stream of water about 1/16 inch (1.5 millimeters ) in diameter.

Comb your hair. Slowly bring the teeth of the comb near the stream of water, about 3 inches (8 cm) below the tap.

What happens?

Try experimenting with different combs, or with more water flowing.

Explanation

Static electricity. When you comb your hair, a charge builds up in the comb and in your hair (this is the same charge that lets you stick balloons to the wall after rubbing them on clothing). This charge attracts the molecules in the stream of water and causes it to bend towards the comb.
Title: Re: What's your kitchen science?
Post by: paul.fr on 18/02/2008 10:44:33
Thanks for the contribution, Doc. I hope you have more to come...and similar contributions from other members would also be nice.

Carrying on with the meteorology related experiments.

What you need


small paper bag and a hard surface


What you do


Blow into the paper bag and close tightly to trap the air inside, then smash the bottom of the bag against a hard surface, without letting go of the bag.

What happens?

Explanation
This is how thunder works. Air rushing out of the bag makes a loud noise. The same thing happens with thunder. Air rushes out of clouds after being heated by lightning. This causes the booming sound.
Title: Re: What's your kitchen science?
Post by: paul.fr on 19/02/2008 10:27:24
What you need


Tall drinking glass, or can with paper removed
Thermometer
Ice cubes
Warm water
Water at room temperature (let it sit for a while)


What you do
 
Put the room temperature water into the glass and add ice, stir with the thermometer until you notice a film of moisture forming on the outside of the glass. Record the water temperature.

Remove the ice and trace your finger on the outside of the glass to make a mark in the moisture. Now raise the temperature of the water slowly, by adding warm water and stirring with the thermometer. Raise the temperature to a point where no moisture forms in the cleared area you marked earlier. When this happens, record the temperature of the water.




Calculate the temperature that is halfway between the two temperatures you recorded, this should be the (or never near to) the dew point temperature of the air.

You can repeat the cooling and warming process several times to see if the results are consistent.

Explanation
This demonstrates 'dew point'.
What is dew point? All air has water vapour in it and warm air holds more than cooler air. When air holds as much water as it can it is said to be saturated. The temperature to which air must be cooled to reach its saturation point is its dew point temperature i.e. 100% humidity. At this point there is a balance between evaporation and condensation. Any cooler and the water vapour will condense as precipitation of some sort. Any warmer and more water will evaporate into the air.
Title: Re: What's your kitchen science?
Post by: lyner on 19/02/2008 22:27:09
Coupled pendulums.
This is a magical demonstration.
You stretch a piece of string between two supports (as taught as possible Two chairs with people sitting in them will do.
You make two pendulums, using potatoes and string (the victorian parlour trick involves potatoes but anything will do). Get them the same length - the more equal the better effect - and tie them to the horizontal string.
Have one pendulum stationary and start the other. The first pendulum will gradually slow down and the other will build up until the first is stationary. the process will reverse. The rate of changeover depends on the amount of 'coupling' between the two pendulums - the support string twists a little and transfers energy from one to the other.
This has interesting connections with quantum physics and many other resonance phenomena.
Title: Re: What's your kitchen science?
Post by: paul.fr on 21/02/2008 07:47:58
What a great experiment, Andrew.

what you need

pencil
paper
scissors
a drawing pin
thread, a coat hanger or piece of dowelling
a lamp


what you do


Draw a spiral on the piece of paper and cut it out carefully, it should look like a long snake. Use the drawing pin to poke a small hole in the middle of the spiral and thread the thread through this hole. Tie a knot in the end to hold it together. Attach the other end to the coat hanger or dowelling and hold the spiral above the lamp

What happens?


explanation
As warm air moves upwards from the lamp it pushes against the underside of the spiralnand makes it spin.
This is how wind works. As warm air rises the air pressure underneath it falls and cooler air nearby moves in to take its place. This sideways moving air is wind.
Title: Re: What's your kitchen science?
Post by: paul.fr on 21/02/2008 15:56:37
what you need

A mirror
clouds


what you do

Place the mirror on a flat area in your garden, or pavement. look at the clouds through the mirror.
What happens?

Explanation
When you Look at the clouds in the sky, you only have other clouds to compare their movement to. If they are all moving in the same direction, they seem to be sitting still (or moving very slowly). If you are looking at their reflection in the mirror, you have the edges of the mirror as a reference point.
This is (roughly) how a Nephoscope works, this is instrument for measuring the altitude, direction, and velocity of movement of clouds.

Why not try looking at the moon through your mirror, does it look to be higher in the sky, or moving quicker?
Title: Re: What's your kitchen science?
Post by: JimBob on 21/02/2008 22:59:20
 
What you need

A glass
Water
A straw
 
What you do

Suck some water up a straw and then put your thumb over the end that is in your mouth. Now keeping your thumb over the straw take it out of the water. What happens?
Now take your thumb off the end. What happens?

Explanation:
This experiment is all about the forces acting on the liquid. One of these forces is gravity, the force which pulls all objects towards the centre of the Earth. Gravity is pulling the water in the straw down towards the Earth, so why doesn’t the water fall out of the straw when your thumb is on top?

There must be another force, stronger than gravity, pushing upwards on the water. This force comes from air pressure. Air pressure is caused by molecules of air pushing against things. Air pressure is very strong and very important. It affects the weather, and the weight of all the air above us in the atmosphere pushing down is a very large force.

When the straw is just sitting in the glass there is nothing separating the air in the atmosphere from the air in the straw. This means that the air in the atmosphere and the air in the straw are pushing down on the water in the glass with the same force. When you suck on the straw it makes the water move up the straw. If you put your thumb over the end it traps the water in the straw, and your thumb separates the water in the straw from the air pressure of the atmosphere. If you pull the straw out of the water and keep your thumb over the end, the water stays in the straw. This is because there is no air pushing the water down from the top of the straw where your thumb is, but the air in the atmosphere is still coming up the open end at the bottom of the straw and pushing up against the water to keep it in the straw. The force from the air in the atmosphere pushing up is stronger than gravity pulling down! If you remove your thumb from the end of the straw the water will flow back out. This is because without your thumb there, the air is pushing with the same force from both ends of the straw. These two pushes cancel each other out so that gravity can pull the water down to the Earth, just as it was trying to do all along!
Title: Re: What's your kitchen science?
Post by: paul.fr on 22/02/2008 09:31:51
what you need


two identical glass jars
four cups of cold water
ten ice cubes
one clear plastic bag
a thermometer


What you do


Split the water and the ice cubes evenly between the jars, and wrap one jar in the plastic bag. Leave both jars out in the sun for an hour.
Measure the temperature in each jar

What happens?

Explenation
In reality, sunlight passes through the atmosphere and warms the Earth’s surface. The heat radiating from the surface is trapped by greenhouse gases (the greenhouse effect.)
In this experiment, the plastic bag acts as the layer of greenhouse gases, trapping heat in the jar and causing the water to become warmer in the jar wrapped in the bag.
Title: Re: What's your kitchen science?
Post by: paul.fr on 23/02/2008 14:27:20
What you need

a large mirror
a dark room
nylon tights/stockings


What you do


Stand in a dark room in front of the mirror and rub the nylon stockings together.
What happens?
Do the same with the wool jumper
What happens?


Explanation
Tiny sparks of static electricity fly back and forth between the two sides of the fabric. When you rub the fabric together electrons build up in one place. When there are lots in the same place, some jump and give off a static charge. This is when you see the spark.

This is how lightning works. On hot and humid days warm, wet air moves upwards very quickly. It forms clouds and the temperature inside the clouds falls. This fast moving air causes an electric charge to build up inside the cloud until the cloud can no longer hold it. The electricity discharges which causes the lightning flash.
Title: Re: What's your kitchen science?
Post by: Make it Lady on 23/02/2008 21:09:00
If you love all these you are going to die when you see this website.

www.planet-scicast.com

It is full of kitchen science u-tube style films. Search for vacuum cleaner bazooka. Some of them have instructions. Happy experimenting.

Heres one from me:

What you need:

Energy saving light bulb
balloon
Dark room
very woolly jumper

What to do:
Stand in the darkened room. Rub the balloon on the wool jumper and charge it up. bring the balloon close to the light bulb and it should light up just for a moment. With practice and a lot of rubbing you should be able to get the bulb to light up brighter and for a longer period. It looks a little like you have super powers and is a great trick to show the kids whilst reading ghost stories.

Wa Ha Ha Haaaa!
Title: Re: What's your kitchen science?
Post by: paul.fr on 06/03/2008 16:26:15
Well it's nearly C.S.I. Friday, so how about a few forensic related experiments.

This one is based on Forensic Osteology, the science of bones, and will show how you can determine someones height using their foot!

What you need


Yourself, or a friend
A ruler or tape measure


What you do


With your socks and shoes off, measure the length of your foot, from heel to toe. Next we will compare that measurement to the length of your forearm. If you measure from your elbow to your wrist, you should find that the distance is pretty much the length of your foot.

If you take the length of your foot and multiply it by 7, that should give you a distance very close to your height. If you are under 20 years old, then this may not work. This is because your bones are still growing.

The length of your foot is also the height of your head, from your chin to
the top of your head.

So, from just a few bones a forensic scientist can make some pretty accurate measurements and conclusions.
Why not try it with your friends and family.
Title: Re: What's your kitchen science?
Post by: Make it Lady on 06/03/2008 17:34:52
Oh Paul I love this one. I once convinced a year 7 pupil that one of the past teachers had really been killed and we had found the bones to examine. The bones were plastic prop.s but this poor kid was convinced it was all real. All these kitchen experiments work so much better if you weave a little story around them. But take care of young gullible children.
Title: Re: What's your kitchen science?
Post by: paul.fr on 07/03/2008 07:44:29
Quote
Posted by: Make it Lady 
Insert Quote
Oh Paul I love this one. I once convinced a year 7 pupil that one of the past teachers had really been killed and we had found the bones to examine. The bones were plastic prop.s but this poor kid was convinced it was all real. All these kitchen experiments work so much better if you weave a little story around them. But take care of young gullible children.

Me too.


What you need

A shoe or foot
A plastic container, about the size of a shallow ice-cream tub.
Plaster of Paris
Mixing spoon
A mixing bowl
Enough moist sand or moist soil to cover the bottom of the container
Rubber gloves


What to do

Put the gloves on and put the sand or soil into the plastic container, and make an imprint of your shoe or foot in the damp sand. If you are not happy with the result, just smooth the sand back over and try again.

Mix up some plaster of Paris until it is nice an creamy, then pour the plaster mixture into the footprint impression. Leave the plaster for about an hour and a half to dry. Once the plaster is dry, remove the cast from the sand. Gently brush off any excess sand.

Why not link this with yesterday's kitchen science. You have a foot cast, can you predict how tall the person was who left the foot print? Is this the print of your suspect, the victim or someone unknown?
Title: Re: What's your kitchen science?
Post by: Make it Lady on 07/03/2008 19:09:28
What about writing a letter saying that you are being black=mailed by the victim and you think you have found a way to stop it. (In other words MURDER THEM!!!)
If you write with an ink pen you can do chromatography on a sample of ink that came from the letter and different types of ink that came from the suspects pens. They have to find out who's pen wrote the letter.
Title: Re: What's your kitchen science?
Post by: paul.fr on 08/03/2008 07:16:20
What about writing a letter saying that you are being black=mailed by the victim and you think you have found a way to stop it. (In other words MURDER THEM!!!)
If you write with an ink pen you can do chromatography on a sample of ink that came from the letter and different types of ink that came from the suspects pens. They have to find out who's pen wrote the letter.

Yes, but first you will need to tell us how to do it. In the meantime, we need to get some fingerprints from that glass we suspect had poison in it.

What you need


Large ziplock bag
Tube of superglue
Drinking glass


What you do



Place the glass into the bag. Make sure you touch the surface using the pads of your fingers, leaving a nice smudge free print.
Lay the bag flat on a counter or work surface and squeeze a few drops of glue into the bag. Do not glue the glass to the bag, now seal the bag tightly and wait a day or so for the prints to develop. You can speed the process  time up by introducing a lamp near the bag, the heat from the lamp should quicken the process.

Explanation
The vapours from the superglue will build up in the bag and crystallize on the fingerprints. A day later, you will see starchy white fingerprints on the surface of the glass.
Title: Re: What's your kitchen science?
Post by: keydetpiper on 09/03/2008 16:33:03
What you need
A good-natured and relatively flexible friend
A wall

What you do
Have your friend bend over and touch his toes (or try at least). No problem! Now ask him to stand with his back and heels against the wall and bend over to touch his toes. Can't do it, no matter how strong or flexible!

What happens
Barely noticeable when someone does it in a room, bending over requires a slight backward shift of the hips. The moves the body's center of mass above the feet, and if the center of mass is above the feet your friend stays upright. With the wall, your friend can't shift his hips backwards, so the center of mass can't move to be over the feet. The result is a rather rather clumsy looking friend.

A variation is to have your friend stand sideways with his right shoulder and right foot against the wall, the tell him to pick up his left foot (the one away from the wall).
Title: Re: What's your kitchen science?
Post by: DoctorBeaver on 09/03/2008 20:29:57
Alka-Seltzer rocket
You will need:-
Empty film canisters or similar
Alka-Seltzer tablets
Teaspoon
Water

Method:-
Remove the canister lid and put 2-3 teaspoons of water into the empty canister
Break off a quarter of an Alka-Seltzer tablet and put it in the lid
Tip the quarter tablet into the canister and shut the lid tightly
Shake the canister for a few seconds and place it lid-down on a flat surface
Stand well back for this one!

If you are a minor, please make sure an adult is present and get permission from your parent or guardian before beginning this experiment.
Title: Re: What's your kitchen science?
Post by: Make it Lady on 09/03/2008 21:30:57
You can also use a fizzy drink as fuel of vinegar and bi-carbonate of soda. The latter launches quicker so you have to be very quick.
Note: The film canister must have an internal seal or it won't work.
Title: Re: What's your kitchen science?
Post by: DoctorBeaver on 09/03/2008 23:10:18
You can also use a fizzy drink as fuel of vinegar and bi-carbonate of soda. The latter launches quicker so you have to be very quick.
Note: The film canister must have an internal seal or it won't work.

I tried it earlier with an aspirin bottle (a plastic 1) and it worked.  [B)]
Title: Re: What's your kitchen science?
Post by: daveshorts on 10/03/2008 13:59:38
Lemon juice is generally slightly less violent than vinegar, but it still has a tendency to blow up in your face if you overegg it
Title: Re: What's your kitchen science?
Post by: paul.fr on 10/03/2008 14:46:19
I tried it earlier with an aspirin bottle (a plastic 1) and it worked.  [B)]

We used to do this in shopping centres, back in they day when all you got was a clip round the ear from a "friendly" policeman. I reckon you could get locked up now.
Title: Re: What's your kitchen science?
Post by: paul.fr on 10/03/2008 14:58:39
Whilst we wait for Sharon to tell us how to determine which pen was used on the blackmail letter, we best start lifting some fingerprints.

What you need


Fingers
Friends
An assortment of drinking glasses
Cocoa powder
A small artists brush
A magnifying glass
Inkpad
White paper, one sheet per person


What you do

Give everybody a glass and a sheet of paper, make sure the glass is clean and has no marks on it. Everybody needs to make a finger or thumb mark on the rim of the glass.

Once this is done, swap glasses (being careful to touch only the base of the glass. Don't smudge the prints that are already there.) Using the brush, place a small amount of cocoa powder over where the prints were  made. lightly dust over the prints to help make them a bit clearer.

On sheets of paper get each person who left a print originally to make another print - but this time they have to press their finger or thumb in the inkpad first.

Match these new prints to the ones you dusted for earlier. Use the magnifying glass to help you inspect them even more closely and try to match them up.

Who left which prints? Who wrote the blackmail letter?


Explenation

No two fingerprints are the same, even twins will have differences in their prints.

When you examine a print you'll notice the lines occur in one of three characteristic patterns, known in the biz as 'arches'. 'loops' and 'whorls'.

When you come to compare the chocolate and the ink prints you should get an exact match between pairs. But although two different people may have the same fingerprint type (eg. both have loops on the same finger), there will always be other little differences between individuals. That's because it's not the shape of the print that’s unique, but rather the number, location and shape of specific ridge characteristics...

What you were lifting with the cocoa powder are called 'latent' prints. These prints are formed by oil and sweat from a person's fingers when they touch a surface - the sweatier you are the clearer they’ll be (so remember to wash after being sweaty)! They're invisible to the naked eye, which is why they need some kind of treatment to help you see them.

Topic link/s
What causes "fingerprints", and why do we all have different ones? (http://www.thenakedscientists.com/forum/index.php?topic=6371.0)
Fingerprints (http://www.thenakedscientists.com/forum/index.php?topic=4346.0)
 How Identical are identical twins ?
 (http://www.thenakedscientists.com/forum/index.php?topic=7623.0)
Title: Re: What's your kitchen science?
Post by: paul.fr on 29/03/2008 22:15:23
What you need


 Red food colouring or joke / stage blood
 Dropper
 Small beaker
 Plain Paper
 Ruler
 Metre rule / tape measure



what you do



Lay out some paper to protect the floor, then place the paper you?ll drop the blood onto on top of them. Hold the dropper 10 cm above a clean sheet of and drip one drop of blood onto the sheet., now measure the distance of the spatter, making sure to write down the height it was dropped from and the diameter of the splatter.

Drop the blood from 20cm higher each time until you get to 200cm or higher if you wish (you can go up in larger or smaller amounts depending on how much time you have). Measure the diameter of the spot and write it down as well as the height it was dropped from.

Use a new piece of paper to drop the blood on every time you change height (this will avoid confusing results), and make sure you?re measuring the distance of the splatter each time you drop the blood.

Once you?ve done this, get someone else to do a splatter at a distance of their choosing (it can be any height within the range of the distances already dropped i.e. 10cm to 200cm). Make sure whoever conducted the test originally can?t see the random drop, because their task now is to work out what height it was dropped from by measuring its splatter and comparing it to their results from before.

If they have recorded their results accurately, then they should be able to make an 'educated' guess what height the random drop was dropped from.


what happens?

This type of forensic analysis is called Bloodstain Pattern Interpretation, or Blood Splatter. What we?re trying to do is re-create the circumstances in which a crime may have been committed.

Once you know about the different ways that blood splatters, and can recognise certain signs, you can begin to work out what happened. It does require some specialist training though.

The specialist will try to determine what the position and shape of the spatter indicate. They take measurements to determine the trajectory as well as carrying out carefully controlled experiments.

These experiments will use materials very similar to those found at the scene, because blood reacts differently depending what surfaces are involved. For example it will behave one way when it hits a carpet, and another when it hits a tiled floor. Using the results of the experiments, investigators can try to reproduce what has happened.


explenation

 Shedding of blood is the dramatic accompaniment to murder committed by violent means. Blood accounts for about 9 per cent of a healthy person's body-weight and as many murderers have discovered to their cost, when it is spilled a little goes a long way.  Once blood is shed in any quantity, and especially when it starts to clot, it becomes very difficult to deal with. Murderers' attempts to clean up after their violent handiwork often fail because of blood-traces which adhere tenaciously to their clothing or to the murder weapon. Blood found at the scene of the crime has trapped many killers who thought they removed all incriminating traces. A sensational demonstration of this was provided by the French detective Gustave Mace in 1869, when he was interrogating a murder suspect in the room which he believed had been the scene of a ghastly crime involving the dismemberment of the victim. Convinced that a great deal of blood must have been shed, Mace looked about the room but could see no obvious traces.  Then he noticed a marked hollow in the tiled floor. With the suspect looking on in astonishment, the detective took a jug of water and tipped the contents on the floor - the water collected in the hollow area, and when the tiles were lifted their under-surfaces were found to be caked with dried blood. This discovery led to a murder confession by Pierre Voirbo and to a triumph of detection for Mace.

Blood is important forensically, and can yield a great deal of information to the investigator. The first task in examining suspicious stains is to determine whether they are blood, and if so, are they human? Once this is established stains are examined for age, sex and blood group. The shape and pattern of liquid blood-splashes can help in reconstructing the murder; bloody fingerprints and palm-prints tell their own story; dried blood on a suspect's clothing can be related to the victim, the crime scene and the murder weapon; blood and tissue forced under the fingernails of the victim during a violent struggle can be linked to the assailant.

Thus a single blood-trace can provide a wealth of information, and analytical techniques are improving all the time. Blood dynamics is important not only for narrowing suspicion on the guilty but also in showing a suspect's innocence. As in many other aspects of forensic investigation, bloodstains are taken into account with a variety of other evidence to build up a pattern of crime.

The investigation of blood at a crime scene can be broadly divided into a biological approach (serology) and a physics approach (blood splatter or bloodstain pattern analysis). This fact file will concentrate on the dynamics of blood evidence.

Examination and interpretation of bloodstains on and around the body, and of blood-spots, splashes and smears at the scene of the crime, are an essential part of a murder investigation. The position and appearance of blood marks on the body and its immediate surroundings will help the investigator to reconstruct the crime.

The theory behind bloodstain pattern analysis is simple: blood is a fluid and will respond accordingly to the laws of physics. Though rarely the dominant piece of evidence in an investigation, bloodstain pattern analysis can be important in the difficult process of reconstructing a violent crime.

Experts begin by taking note of a few key variables:

    * spot size
    * quantity
    * shape
    * distribution
    * location
    * angle of impact
    * target surface

A great deal can be gleaned from the shape of blood spots and splashes found on surfaces such as floor, walls, ceiling, woodwork and furniture. The French criminologist Alexandre Lacassagne noted the correlation between the shape of blood sports and the position of the victim. Blood dropping vertically on to a flat surface form a circular mark with crenated edges, and denotes that the source was stationary at the time. Drops of blood falling from a moving object hit a flat surface obliquely and leave a spot shaped like an exclamation mark. An examination of the shape of obliquely falling blood splashes yields information about the direction and speed of impact. Such evidence helps determine the positions of victim and murderer at the time of an assault, and may also indicate the manner of violence and type of weapon used.

A line of blood spots on the ceiling of a room in which violent murder has been committed is likely to have been made by the killer wielding an axe or bludgeon in an area over his head. Smears and trails on the floor may be produced by a wounded person crawling about or by an assailant dragging the body of his injured victim. Smudges and smears on furniture and doorsteps leaving bloody fingerprints or palm prints may result from similar activities. Blood smears tend to start as drops which become ragged at one edge, indicating the direction of travel.

Large spots - the blood was travelling at a relatively low velocity.
   

Small spots - the blood was travelling at a relatively high velocity. (More force equals smaller splatter)
   

Elongated drops - victim was moving, their speed relative to the amount the spots are stretched and how far they are spaced apart. (Also indicates directionality)
   

Contact - large stain on a surface caused by contact with a bloody object.

Void in otherwise uniform splatter - something blocked the blood spray.
   

Cast-off - straight, elongated lines of splatter indicating that blood was thrown by a moving object in a change of direction. (Can show how many times a victim was struck)


Even when the blood stain is not evident it may still leave a tell tail fingerprint. To detect invisible blood stains, the luminol test is used, which is a chemical sprayed on carpets and furniture which reveals a slight phosphorescent light in the dark where bloodstains (and certain other stains) are present.

What is the luminol test?

The specialist will try to determine what the position and shape of bloodstains at the crime scene indicate. He/she take measurements to determine the trajectory as well as execute carefully controlled experiments. These experiments will use surface materials like those found at the scene to try to reproduce what has happened.

A leading authority on blood stain interpretation gives the following tips to investigators:

    * It is possible to determine the impact angle of blood on a flat surface by measuring the degree of circular distortion of the stain. In other words, the shape of the stain tends to change depending upon the angle of impact which caused the stain. For example, the more the angle decreases, the more the stain is less circular and more long.
    * Surface texture is one of the key components in determining spatter type. The harder the surface is, the less spatter will result. It is therefore extremely important to duplicate the surface in a controlled test.
    * When a droplet of blood hits a surface which is hard as well as smooth, the blood usually breaks apart upon impact. This in turn causes smaller droplets. The smaller droplets will continue to move in the same direction as the original droplet.

One of the classic murder cases in which blood evidence played an important, if controversial part was the trial of Dr Sam Sheppard. The doctor's wife was found dead in their Cleveland Ohio, home in July 1954. Her body, with the head brutally battered by over thirty blows from a heavy object was found in the master bedroom. The room, which had been ransacked, was heavily spattered with blood, and a trail of stains led down the stairs and out on to a terrace.

Dr Sheppard, who had been awakened from sleep on the living room sofa by his wife's screams, claimed to have been knocked unconscious by an intruder as he rushed upstairs. His behaviour was judged to have been suspicious, and there was considerable prejudice against him, not least on account of his alleged infidelity. He was sent for trial and found guilty of second degree murder, for which he was sentenced to life imprisonment. The coroner had made much of bloodstains on the pillow in the murder room, and a bloody imprint which he suggested had been caused by a surgical instrument which had served as the murder weapon. This instrument was never specified, but the imputation was plain that Sheppard, himself a doctor, had used it to murder his wife. The murder room abounded in blood evidence which if properly examined would have led to other conclusions. It was left to Dr Paul Leland Kirk, Professor of Criminalistics at Berkeley, to make a thorough assessment of this evidence several months later in order to reconstruct the murder. As the bedroom ceiling showed no traces of blood, Kirk reasoned that the murder weapon had been wielded in a more or less horizontal fashion. This was borne out by the state of blood splashes on the walls, some of which had been flung from the murder weapon as it was swung backward and forward to make contact with the victim's head. Other blood spatters had come directly from the battered head. The Professor carried out experiments which suggested the most likely weapon to have caused the pattern of blood splashes was a heavy flashlight. He also judged that the murderer stood between the twin beds, having noted blood drops which had been smeared into streaks on the right side of the victim's bed. This interpretation was supported by blood free areas on two of the walls behind the murderer which had been protected from flying blood spatters by his body. A killer standing in that position must have swung the murder weapon with his left hand - Dr Sheppard was neither left-handed nor ambidextrous.

By implication, the murderer must have been thoroughly spattered with blood. Yet apart from a bloodstain on the knee of Sheppard's trousers, which got there when he stood close to the bed to take his wife's pulse, there was no evidence of other blood staining on his clothes A number of factors similarly pointed away from Dr Sheppard as the murderer - it was certainly the case that the examination of the blood evidence had been bungled in the first instance. There was no better illustration of this than the admission during a second trial that the trail of stains leading from the bedroom through the living room and out on the terrace had not even been properly tested for human origin, nor was blood groupings attempted. Professor Kirk's interpretation of the blood evidence went a long way towards securing Dr Sheppard's eventual freedom.

Film and television aficionados may recognise the recognise in this case the opening premise of The Fugitive. Obviously the series would have been a lot shorter with the help of a good bloodstain expert.

Some common terms used in bloodstain pattern interpretation.

    * Angle of Impact  --  The acute angle formed between the direction of a blood drop and the plane of the surface it strikes.
    * Cast-Off Pattern  --  A bloodstain pattern created when blood is released or thrown from a blood-bearing object in motion.
    * Drip Pattern  -- A bloodstain pattern which results from blood dripping into blood.
    * Flight Path --  The path of the blood drop, as it moves through space, from the impact site to the target.
    * Flow Pattern  --  A change in the shape and direction of a bloodstain due to the influence of gravity or movement of the object.
    * Impact Pattern  --   Bloodstain pattern created when blood receives a blow or force resulting in the random dispersion of smaller drips of blood.
    * Misting  --  Blood which has been reduced to a fine spray, as a result of the energy or force applied to it.
    * Projected Blood Pattern  --  A bloodstain pattern that is produced by blood released under pressure as opposed to an impact, such as arterial spurting.
    * Spatter  --  That blood which has been dispersed as a result of force applied to a source of blood.  Patterns produced are often characteristic of the nature of the forces which created them.
    * Target  --  A surface upon which blood has been deposited.
    * Transfer/Contact Pattern  --  A bloodstain pattern created when a wet, bloody surface comes in contact with a second surface.  A recognizable image of all or portion of the original surface may be observed in the pattern.
    * Wipe Pattern  -- A bloodstain pattern created when an object moves through an existing stain, removing and/or altering its appearance.

Forensic Serology (http://www.policensw.com/info/forensic/forensic6c.html)



Title: Re: What's your kitchen science?
Post by: paul.fr on 06/04/2008 15:27:51
What you need

a drinking glass
ice


what you do


Outside on a cold day you often see your breath turn into a white mist that looks somewhat like a cloud, but why? and can we duplicate this effect?

Take a short glass or plastic cup and put ice in it, filling it no more than halfway, then gently blow across the top of the glass or even slightly down into it until you see your breath making a white mist. If you are unable to see a white mist sprinkle some rock or table salt into the ice, mix it up a little and and then try blowing across the top of the glass again.

explanation
This happens because your breath is warm and it can hold more water vapor than the cold air outside. Some of the water vapor in your breath quickly condenses out into tiny water droplets that you can see.
topic link/s


Title: What's your kitchen science?
Post by: paul.fr on 10/04/2008 21:24:26
The Coriolis effect has been discussed recently on the forum, but what is it and can we visualise it's effect with just a piece of paper, a pencil and a few spare seconds?

What you need


A piece of paper, say A4
A pencil


What you do


Steadily, and carefully, rotate the piece of paper clock or anticlockwise with one hand, and attempt to draw a straight line from one edge of paper to the centre. You may want to mark the centre of your rotation with a small circle to begin with, this will represent one of the poles.


What happens?


Explanation
To begin with, we should know what the wind is and what causes it. The ultimate cause of Earth's winds is solar energy. When sunlight strikes Earth's surface, it heats that surface differently. Surfaces such as snow, sand and soil absorb different amounts of heat. This creates uneven heating of the earths surface, this leads to a difference in air pressure.


As a result we have differences in air pressure (and heat)over the earth, high and low pressure. Very simply, At the equator hot air rises and moves out towards the poles, gradually cooling. It eventually sinks back down to the earth's surface. This cooler air is then forced to flow back to the equator to replace the hot air that is rising. This is wind.

The Coriolis force results in a deflection of air to the right of the direction of the pressure gradient force

Watch this video (http://www.classzone.com/books/earth_science/terc/content/visualizations/es1905/es1905page01.cfm?chapter_no=visualization)

Wind Circulation (http://www.bbc.co.uk/weather/features/understanding/wind_circulation.shtml)

understanding coriolis (http://www.usatoday.com/weather/resources/basics/coriolis-understanding.htm)

pressure gradient force (http://en.wikipedia.org/wiki/Pressure_gradient_force)
Title: What's your kitchen science?
Post by: Bass on 12/04/2008 21:34:34
PANNING FOR GOLD

For anyone interested in panning for heavy minerals (gold, platinum, metallic minerals, iron minerals, and others including rubies, sapphires and garnets)- here is a brief "How to" guide.  Takes a little time and effort.

What you need

gold pan (I recommend green plastic pans with built in riffles)
shovel
waterproof boots and gloves
small jar (to store all the nuggets!)
small magnet wrapped in Saran Wrap

In streambeds, try to dig down to bedrock if possible, or get as deep as possible.  Also look for areas of slack current, such as on the lee sides of boulders.  For beach sands, try to either collect sand that is on bedrock, or find places in the sand where heavy minerals (magnetite, limonite, hematite, illmenite, zircon) collect (a magnet wrapped in Saran Wrap will help you find magnetite if any exists). 

Best to fill the pan about 3/4 full, then in calm water, work the sand/gravel with your hands until you get rid of all the mud/silt (fill the pan with water, work the sediment until muddy, then pour off the muddy water- continue until water stays somewhat clear when stirred up).  The green platic gold pans with riffles built in make this much easier.

Fill with water, then rock the pan gently back and forth while slowly swirling it in a circular motion (this is to get the heavy material to sink to the bottom).  After you've agitated the pan enough to get the heavies to sink, slightly tilt the pan and allow the water with the top layer of light material to wash out.  You can dip the tilted pan into the water several times to allow the top material to wash out.  Fill with water again, swirl and rock the pan, flush out the top layer.  Repeat this until only a small amount of material remains in the bottom of the pan (often this will be mostly black).  You can pick out any obvious non-mineralized pieces of gravel, as these will also sink to the bottom since they are heavier than the sand.  Gently swirl the pan letting the heavy material in the bottom move a few mm at a time, then use a magnifying glass and see if a thin gold line exists at the back (the gold will not move much since it is heavier).  You can remove magnetite (most common black sand residue) with a magnet wrapped in food wrap.

With practice, you can do this in a few minutes- first timers generally take 15-25 minutes.  This is much more enjoyable when the air and water temperatures are warm, otherwise wearing waterproof gloves really helps.

Good luck and have fun!
Title: What's your kitchen science?
Post by: paul.fr on 21/04/2008 17:04:46
What you need


Cotton Wool balls
Pippet or eye dropper
Glass of water


What you do

hold the cotton ball in one hand and the eyedropper in the other. The best way to hold the cotton wool ball is to hold a small portion of the cotton ball between the thumb and index finger.

With the pippet put as many drops of water into the cotton ball as possible. The cotton ball will be full (saturated) when water begins to drip from the bottom. How many drops of water do you think it will take for the cotton wool ball to become saturated?


Explanation

Since no two cotton wool balls are the same, and the drops will all be different, this is what is happening in nature and the formation of clouds. The cotton wool ball represents a white fluffy cumulus cloud.

One inch of rain over one square mile equals 17.4 million gallons of water weighing 143 million pounds (about 72,000 tons). The 'average' cumulus cloud is made up of over 10,000,000,000,000 drops and weighs about 2 billion pounds!
Title: What's your kitchen science?
Post by: neilep on 21/04/2008 18:40:37
What You Need:

Two balloons
A Funnel
Water
A Candle
A grown up (if you are a youngie)


What you Do !

Blow one balloon up , secure it and move the candle towards it....it POPS !!!

Fill the second balloon with just a small amount of water..half a cup lets say.
Blow the balloon up...secure it.

Light the candle and slowly move the candle towards the balloon placing the flame where the water is.

What happens ?..or what does not happen ?




Explanation


Don't let the flame heat the bottom of the balloon indefinitely as it WILL burst....but...you should be able to have the flame beneath the balloon for a while. Even to the point where the rubber is gaining a lot of soot from the candle.

Just as the rubber reaches popping temperature , the water inside absorbs the heat and stops it from popping.
Title: What's your kitchen science?
Post by: paul.fr on 22/04/2008 17:05:05
What you need:

Two empty drinks cans
A level surface


What you do:


Lay the two cans parallel to each other, about one inch apart, near the edge of a level surface. Get down to the level of the floor/surface and blow between the two cans.

What happens?

It may take some practice, but the two cans will roll together.

Explanation:

The affect is Bernoulli's principle in action, named after the Dutch/Swiss mathematician/scientist Daniel Bernoulli. By blowing between the two cans, you are making the air between them move faster than the surrounding air. The cans roll together as the higher pressure surrounding the two cans pushes the cans together toward the region of lower pressure.

Title: What's your kitchen science?
Post by: paul.fr on 23/04/2008 12:58:14
What you need


Two, empty two litre bottles (plastic)
hot tap water


What you do


Put two or three cups of hot tap water into each of the bottles, then put your thumb over each bottle opening and shake for about thirty seconds to a minute.

Pour the water out of each bottle and screw the bottle lid on one of the two bottles. Place the two side by side an observe for about 10 minutes.


What happens?


The bottle that had the lid screwed on Should have collapse, yet the other bottle should remain unchanged.


Explanation

The bottle collapsed due to the air cooling inside that bottle. The air cools because the molecules and atoms inside the bottle loose energy as they collide with the bottle side that is exposed to the cooler surrounding air. As their energy decrease so does their velocity and therefore the pressure decreases. Since the pressure inside the bottle decreases, the force of the air outside the bottle begins to crush the bottle.

However the uncapped bottle remains unchanged. As the air cools inside, the drier outside air flows in to take up the space thereby keeping the pressure the same both inside and outside of the bottle.
Title: What's your kitchen science?
Post by: paul.fr on 28/04/2008 14:52:29
What you need


Two table tennis balls / ping pong balls
Hair drier


What you do


Point the nozzle of the hair drier upwards and turn it on to full power, it can be blowing cool air as there is no need for heat. Place one of the balls into the stream of air, and then carefully add the second.


What happens?

Both balls should be suspended by the air, they will occasionally collide with each other making a clicking sound.


Explanation:

Had the balls been raindrops, every time they collided, they would have joined each other, making a larger drop of water.

In rising (cooling) air, water vapor begins to condense on cloud condensation nuclei when the air has cooled to the dew point temperature. As the air continues to rise and cool, water vapor will eventually condense onto the cloud condensation nuclei and form cloud droplets. Since there are many sizes of cloud condensation nuclei in any given air parcel, the cloud droplets that form will be different sizes as well.

As a result of the cloud condensation nuclei size distribution, some cloud droplets will be larger than the rest. Eventually, the largest cloud droplets begin to fall faster than the smaller droplets because large drops have faster terminal velocity than small drops. As these large cloud droplets fall, they collide with the small cloud droplets.

Many times, these droplets will stick together and become one large drop (coalesce). Eventually these droplets fall from the cloud as raindrops, reaching a diameter of approximately 10 mm (0.39 inches). After a raindrop reaches 10 mm, it becomes so large that it breaks up into smaller drops.
Title: What's your kitchen science?
Post by: paul.fr on 03/05/2008 16:44:52
What you need


A freezer
A piece / block of polystyrene


What you do


Pop the polystyrene in to the freezer and leave for 24 hours, take it out.
What has happened?

You should notice that the polystyrene is not frozen and in fact feels warm to the touch!

Explanation:

Hay, don't look at me for an explanation!
Lets throw it open to the forum members.

Link:
Why does polystyrene not freeze? (http://www.thenakedscientists.com/forum/index.php?topic=14289.new#new)
Title: What's your kitchen science?
Post by: Bass on 08/05/2008 05:31:53
COSMIC RAY CLOUD CHAMBER

What you need

Wide-mouth Canning jar (1 pint or 450ml size works well)
Metal pan
Felt cloth
glue or double stick tape
pure isopropyl alcohol
dry ice
flashlight

What you do

Cut the felt cloth in a circular shape to fit jar lid
Attach felt cloth to the inside of the jar lid (don't cover the rubber seal)
Pour a small amount of alcohol into the jar (enough to thoroughly wet the cloth plus a little extra)
Seal the jar (a tight seal is necessary)
Place the jar upside down on top of dry ice in the pan
          Remember to wear gloves when handling dry ice

What happens

Due to the temperature difference (warm jar and cold lid), the alcohol will begin to condense and form an alcohol "fog"
As cosmic ray particles travel through the jar, they will ionize particles along their path, causing intense condensation (look for streaks like contrails from jets)
Shining the light at different angles may illuminate the cosmic ray streaks better
Only a thin layer of "fog" will form just above the lid with felt cloth at the bottom.
Title: What's your kitchen science?
Post by: paul.fr on 08/05/2008 14:19:46
Excellent, as usual Bass
Title: What's your kitchen science?
Post by: paul.fr on 08/05/2008 14:19:53
What you need


A large, clear plastic bag
rock
A tree


What you do


Place the plastic bag over a limb/branch of the tree (or large bush), making sure that the limb is high enough off the ground so that the added weight of the rock will not make it touch the ground.

Making sure that there are no air leaks or holes, tie the open end of the bag around the tree (or bush). At the closed end of the bag, tie a rock to the bag so the bag is weighted and forms a collection point for the water.

After six hours or so, poke a hole in the bag and collect and measure the water. Then remove the bag from the branch



What happens?


The bag should have some water in it.


Explanation


Transpiration:
There are two methods water moves from the ground to the atmosphere as part of the hydrologic cycle. Transpiration is basically evaporation of water from plant leaves. Studies have revealed that transpiration accounts for about 10% of the the moisture in the atmosphere.

And this is an, easier to swallow, way to get drinking water than drinking your own urine (http://www.thenakedscientists.com/HTML/content/kitchenscience/exp/how-you-could-drink-your-own-urine-safely/)!
But if you must, or want to get someone else to drink their own urine follow the above link.
Title: What's your kitchen science?
Post by: paul.fr on 13/05/2008 14:47:38
What you need

A Barometer
Graph paper pencil


What you do

Draw your bar chart like the pathetic picture below

 [ Invalid Attachment ]

At regular (say, 2 hourly) intervals over a nember of day plot the reading of your barometer on the graph. After a week you should have something that looks like this:

 [ Invalid Attachment ]

Explanation

Have you ever seen the "pressure" charts on weather forecasts and wondered what they are and why they are relevant to you and the weather?

Like all fluids, the air exerts a pressure on everything within and around it, although we are not aware of it. Pressure is a force, or weight, exerted on a surface per unit area, and is measured in Pascals (Pa). The pressure exerted by a kilogram mass on a surface equals 9.8 Pa. The pressure exerted by the whole atmosphere on the Earth’s surface is approximately 100,000 Pa. Usually, atmospheric pressure is quoted in millibars (mb). 1 mb is equal to 100 Pa, so standard atmospheric pressure is about 1000mb. In fact, actual values of atmospheric pressure vary from place to place and from hour to hour. At sea level, commonly observed values range between 970 mb and 1040 mb. Because pressure decreases with altitude, pressure observed at various stations must be adjusted to the same level, usually sea level.

Atmospheric pressure is measured by a barometer. A mercury barometer measures the pressure by noting the length of mercury which is supported by the weight of the atmosphere. One centimetre of mercury is equal to 13.33 mb, so normal atmospheric pressure can support a column of mercury about 75 cm (or 30 inches) high. An aneroid barometer is a more compact instrument for measuring pressure. It consists of a box of partially exhausted air which expands and contracts as the pressure falls and rises. The box is connected through a system of levers to a pointer which, in conjunction with a dial, indicates the pressure.

Air blows from regions of high atmosphere pressure ("highs" or anticyclones) to regions of low atmospheric pressure. In a high-pressure system, air pressure is greater than the surrounding areas. This difference in air pressure results in wind, or moving air. In a high-pressure area, air is denser than in areas of lower pressure. The result is that air will move from the high-pressure area to an area of lower density, or lower pressure. Conversely, winds tend to blow into low-pressure areas because air moves from areas of higher pressure into areas of lower pressure. As winds blow into a low, the air can be uplifted. This uplift of air can lead to the development of a depression with clouds and rain.

Air moving from high to low pressure does not however, follow a straight-line path. In fact, the air moving from high to low pressure follows a spiralling route due to the rotation of the Earth beneath the moving air, which causes an apparent deflection of the wind to the right in the Northern Hemisphere, and to the left in the Southern Hemisphere.

 [ Invalid Attachment ]

 [ Invalid Attachment ]


After a week, what does you graph show? How was it relevant to the weather you had? Notice any peaks and troughs in your chart, what was the weather like during those periods?


Title: What's your kitchen science?
Post by: Andrew K Fletcher on 15/05/2008 19:45:00
A Human Physiology Experiment to show how gravity alters your heart and lung function.

What you need

A bed
Two 15 centimetre blocks or strong plastic tubes (to raise the head end of the bed).  (If your bed joins in the middle then Two 7.5 centimetre blocks to support the join in the middle will also be required)
A stethoscope (Or you can find a pulse with you fingers placed on the inner wrist area)
A clock or watch (to record the time and measure rates against minutes)
A mum or dad   (to monitor your heart rate and respiration rate).
And some serious ZZZZZ’s / sleep

Ask mum to measure your heart rate and respiration rate while sleeping horizontally, taking care not to awaken you and making a note of your breathing and heart rate.

Then the following night tilt the bed by raising the head end 15 centimetres higher than the foot end of the bed.

Ask mum or dad to repeat the same measurements and make a note of them for comparison.

Double cross over:

This is the fun part. All good science is repeatable so we switch the rolls in our simple experiment and you measure your mum and dad’s heart and respiration rate when they are sleeping horizontal and again when they are sleeping on an incline.

If either awakens then you must wait for them to go back to sleep and try again so Shhhh and be quiet as a mouse.

Although this may seem like a simple experiment. This is a very important experiment and your observations will help greatly to improve our knowledge of human physiology and how circulation relates to posture and gravity.

You can also perform the same experiment on your pet dog using pillows to tilt his or her body, but wait until your dog is sleeping.

So please come back and tell us all what you have found in the Nakedscientists forum.
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fi209.photobucket.com%2Falbums%2Fbb31%2FAndrew_K_Fletcher%2FWeb%2520Page%2520Pictures%2FImage16.gif&hash=de9ffda9d1d539e6f593def4ec4297ff)
Title: What's your kitchen science?
Post by: paul.fr on 20/05/2008 14:06:41
What you need

a wooden, cooking skewer
a lighter
3% hydrogen peroxide
a cup or glass
yeast


What you do

Pour some hydrogen peroxide into the glass. Sprinkle some of the yeast into the peroxide and give it a stir. Very quickly you will see bubbles rising, producing foam on top of the liquid.

Light the end of the wooden skewer, and let it burn for a moment. Then blow out the flame. If you blow gently on the burning end, you should see a red glow. It is still burning, but not flaming. Carefully bring the glowing end of the skewer up to the larger bubbles in the foam.


What happens?

The skewer should flare up, bursting into flame.


Explanation

What, you expect me to know why this happens? Best check this topic for answers
http://www.thenakedscientists.com/forum/index.php?topic=14661.new#new
Title: What's your kitchen science?
Post by: neilep on 20/05/2008 14:14:40
PAUL.....fantastic thread as always..

...Paul....have you written here how to make clouds in a bottle ?.....I saw it somewhere and can't quite remember it.....I don't want to post it if I am wrong about the implementation of it !
Title: What's your kitchen science?
Post by: paul.fr on 20/05/2008 14:18:36
PAUL.....fantastic thread as always..

...Paul....have you written here how to make clouds in a bottle ?.....I saw it somewhere and can't quite remember it.....I don't want to post it if I am wrong about the implementation of it !

Thanks, Neil....Oh, and thanks to Mr Fletcher, i think ;-)
I may have done, but just post it anyway Neil.
Title: What's your kitchen science?
Post by: neilep on 20/05/2008 14:34:11
CLOUD IN A BOTTLE 


What You Need


    * 2-liter clear plastic pop bottle
    * matches (children will need adult assistance to light matches)
    * warm water


What You Do


Fill the clear plastic 2-liter bottle one-third full of warm water and place the cap on. As warm water evaporates, it adds water vapor to the air inside the bottle. This is the first ingredient to make a cloud.

Squeeze and release the bottle and observe what happens. You’ll notice that nothing happens. Why? The squeeze represents the warming that occurs in the atmosphere. The release represents the cooling that occurs in the atmosphere. If the inside of the bottle becomes cover with condensation or water droplets, just shake the bottle to get rid of them.

Take the cap off the bottle. Carefully light a match and hold the match near the opening of the bottle.

Then drop the match in the bottle and quickly put on the cap, trapping the smoke inside. Dust, smoke or other particles in the air is the second ingredient to make a cloud.

Once again, slowly squeeze the bottle hard and release.


What happens?

 A cloud appears when you release and disappears when you squeeze. The third ingredient in clouds is a drop in air pressure.

EXPLANATION
:

Water vapor, water in its invisible gaseous state, can be made to condense into the form of small cloud droplets. By adding particles such as the smoke enhances the process of water condensation and by squeezing the bottle causes the air pressure to drop. This creates a cloud!



Title: What's your kitchen science?
Post by: paul.fr on 21/05/2008 01:12:17
What you need

plastic lids (jam jar type/size)
petroleum jelly / vasaline
magnifying glass
paper punch
String or cotton
windy day


What you do


Punch a hole at one end of each lid.
Thread each hole with a length of string and knot the ends together to form a loop for hanging.
Spread petroleum jelly over one side of each lid.
Take the lids outdoors on a windy day and hang them in various areas.
Leave them outside for about an hour or two to collect what may be blowing in the wind.
Retrieve the lids and see what they have collected.


what happens?

You may have collected insects, dirt, seeds and leaves. Use the magnifying glass for further observation.

EXPLANATION

The wind collects items as it blows through tree's, grass etc.


















Title: What's your kitchen science?
Post by: neilep on 21/05/2008 15:48:33
TORNADO IN A JAR  [ Invalid Attachment ]

What You Need


    * mayonnaise jar or a canning jar
    * clear liquid soap
    * vinegar
    * water

What You Do

Fill the jar about three-quarters full of water.

Put a teaspoon of the liquid soap into the jar.

Also, add a teaspoon of vinegar into the jar.

Tighten the lid and shake the jar to mix up the ingredients.

Now, swirl the jar in a circular motion.

The liquid will form a small tornado.

*If you want to get creative, you can also use food coloring to make the tornado have a color and glitter to represent debris

EXPLANATION:

The swirling motion you give the bottle forms a vortex and is a easy way to create your own tornado.
Title: What's your kitchen science?
Post by: paul.fr on 22/05/2008 19:09:58
What you need


a film canister (or similar) filled with soil, with the lid on
two clear plastic glasses
water
two ice cubes
a marker pen.



What you do


Place the film canister upside down into one cup. This represents an island, such as Antarctica. Half fill each glass with water and place one ice cube on top of the ‘island’ and the other ice cube in the water in the second glass.

Mark the level of the water on each glass.

Once both ice cubes have melted, see whether the water level has risen.


Explanation

The ice cube floating in the water has already shifted, or displaced, the water in the glass; so when it melts, the level will barely rise. But the ice cube on the land (film canister) will not displace the water until it melts and drips into it, making the water level rise.

Only the melting of land-based ice and snow (like Antarctica) will increase the sea level. The melting of floating ice (like the North Pole) will not affect the sea level much.
Title: What's your kitchen science?
Post by: paul.fr on 27/05/2008 19:54:43
What you need


a tall, clear glass or jar
water
vegetable oil
rubbing alcohol
corn syrup or other sugary syrup
a variety of small objects such as: cork, rubber, plastic, bread, corn flakes, ice, a piece of apple, slice of lemon, slice of lime, etc.
a spoon


What you do


Pour about one and a half inches of corn syrup into the glass. Place the ladle just at the top of the layer of syrup and gently pour in another inch or so of water. The water should form a layer on top of the corn syrup, and by pouring it into the ladle, you keep from mixing the two layers. Keeping the ladle in place, add an inch or so of cooking oil to form the next layer. Once that is settled, add an inch of rubbing alcohol for the top layer. When you finish, place the glass on the table and look at it from the side. You should be able to easily see the different layers of liquid.

The corn syrup is the densest, so it is on the bottom. Next is the water, then the oil, and last is the alcohol, which is the least dense. Now, drop a small piece of bread into the glass. It will float for a second and then as it soaks up the alcohol, it will sink. It does not go all the way to the bottom. Instead, it sinks down to the top of the oil. Soggy bread is denser than the alcohol, but less dense than the oil, so it floats at the boundary of the two.

Drop in raisins, buttons, olives, pieces of plastic, coins, corks, and any other small objects that won't be hurt by putting them into the liquid. Notice which layer each floats on. That tells you their relative density.


Explanation

If an object floats in a liquid then you know its average density is less than the liquid and vice versa.


http://www.thenakedscientists.com/forum/index.php?topic=14732.0;topicseen#quickreply
Title: What's your kitchen science?
Post by: paul.fr on 01/06/2008 16:21:33
What you need

an empty pint-sized milk (or similar) carton
water
two small thermometers
cotton shoelace
string
clear tape


What you do
 
Cut a piece of shoelace 1 inch long and pull it over the bulb of one thermometer, and Tie it in place so it
won’t fall off. Tape the thermometer to one side of the carton and wet the shoelace.

Tape the second thermometer to another side of the carton.

Punch two holes in the top of the carton (the 'lip' area where the expiration date is stamped) and thread a long piece of string through these holes and tie the ends together to form a large loop. You should have something that resembles a box with a long handle.

Go outside and swing the carton overhead while holding onto the string. Do this for one minute. Then Quickly look at the temperatures on the two thermometers and write them down.

What are the temperatures?
Are they different?

Explanation

The temperature of the thermometer with the wet bulb should be lower than the temperature of the thermometer with the dry bulb. This is because water is evaporating from the wet bulb thermometer and cooling it down. The difference between the two temperatures will help you calculate the Relative humidity and dew point.
Title: What's your kitchen science?
Post by: paul.fr on 03/06/2008 16:17:18
A member sent this to me...

What you need


Chocolate sauce
Red food dye
Water
Measuring cup
Mixing bowl
Drinking straw
Old clothes
5 large sheets of white paper (at least A3 size)
Scientific calculator


What you do


To make your fake blood, measure 3 parts chocolate sauce to 1 part water into your mixing bowl. Make about one or two cups of mixture then add a dash of red food dye and mix. Add more dye if you feel it is needed.

Lay the sheets of paper in a line, end to end, in an open, outdoor area. You might need to weigh them down so they aren't blown away.

Dip your drinking straw into the fake blood. Gently suck a small amount into the straw, being careful not to drink it (as tempting as it might be!).

Place a thumb over the end of the straw your mouth was on.

With your thumb still in place, stand about 2 to 3 metres away from the end of the line of paper. Starting with your hand down low, remove your thumb and quickly sweep the arm holding the straw in an upward motion. The aim is to flick a line of fake blood out over the paper. It might take some practice to get a nice line of drops you can investigate.

Dip your straw into the fake blood again. This time, walk over to the paper and let one or two drops fall onto it from straight above.

Look at the different drops you made. What shapes are there? Are some drops longer than others? Do some have pointed ends? In which direction do they point?


Explanation


Asked to draw a rain drop, many people draw the typical 'tear' shape with a round lower end and a long tail pointing up. In reality, falling drops of liquid are near perfect spheres.

Blood is no different. A single drop of blood falling straight down descends as a sphere, so it makes sense when it hits a surface it will make a neat circle. However, blood often doesn't fall straight down. If blood is thrown (or 'cast') from a weapon, flicked from a wound, or ejected from an artery by the pressure of a pulse, the drops will often hit a surface at an angle. Rather than round, the drop will be elongated and often have a pointy tail.

As the drop strikes the surface from a steep angle, most of its volume will stick. Inertia carries the rest of the drop forward, often ending in a thin line or tail. Therefore the tail always points away from where the blood drop originated.

Investigators can then use trigonometry to calculate the angle of impact and trace this back to an approximate starting place. Trigonometry is an area of mathematics that describes the relationship between the length of sides and angles in a right-angle triangle. The longer the drop is, the lower the angle will be. It helps to think of the length of a drop as the longest side (hypotenuse) of a right-angled triangle. Since we know the drop started as a sphere, the width of the drop will be the same as its height, giving the second side of the right angled triangle.

The 'sine' of an angle describes the ratio of the angle's opposite side to the hypotenuse. To work out the angle of impact, we measure the drop's width and divide it by its length. The resulting number is the same as the sine of the angle. However, we just want the angle (not the sine of the angle). Most scientific calculators will have a function which looks like 'sin -1 '. This is called its inverse. Use this on your number and it will give you the angle at which the blood hit the surface.


Application


Even if somebody personally witnesses a crime, it can be difficult to know precisely what happened. If somebody is wounded, falling or flying blood can tell investigators where the victim was standing, what type of injury they have, the nature of the weapon used against them and how badly injured they are. By using the angle of impact of a number of blood drops, a person's movements through the crime scene and the actions they performed can often be described.

Trigonometry is used extensively in fields such as forensics, where angles need to be calculated from a few clues. For instance, ballistics experts – who study projectiles like bullets – often use it to trace back from bullet holes to the point of origin.
Title: What's your kitchen science?
Post by: techmind on 12/06/2008 23:08:42
Experiment with thermal paper

(At Paul's suggestion, I'm re-formatting and posting the experiment originally inspired by and suggested at http://www.thenakedscientists.com/forum/index.php?topic=14879.0 )


The till-receipts from many shops these days, and many bus tickets, are printed on "thermal paper" - much like that traditionally used in FAX machines. The paper is coated with a substance which turns black (strictly dark brown) when it is heated. "Printers" can therefore mark the paper merely by heating it somehow, rather than needing any ink.
Unfortunately for folks hoping to claim on a warrantee, the print has a nasty habit of fading over a period of months!

(copied from previous thread)
I can't help with *why* they fade, but I can clarify that it's primarily the receipts printed on "thermal paper" which do fade. The thermal paper turns black (actually dark brown) when it's heated - but gradually returns to white over many months. This is exactly the same technology that used to be used for faxes... and has become popular for store receipts over the past decade.
The only way to keep permanent copies is to photocopy the receipts soon after you get them.

Kitchen science experiment: hold an (unwanted) receipt or bus ticket somewhere hot** and see it turn black.
** Hot = momentarily against a 25 or 40W lightbulb, in the steam from a kettle, or against a particularly hot household radiator.


I'm fairly sure that an old faded receipt can be blackened again by heating, ie the process reverses - as opposed to a decomposition. If you have an old (and now unwanted) receipt you might try this.

It's interesting that if you hold the receipt in the steam from a kettle (I did more experiments at the weekend) the blackened bit momentarily gets lighter again while in the steam (the hottest part???), but then settles to dark-brown as it cools. The dark/light swirls around a bit with the air/steam flow. It's rather fun to watch.


---------------------------------

Bonus experiment (Oct. 2008), following a random internet tip-off

Apply a piece of Scotch tape to a thermally-printed receipt, and the printing underneath the tape will fade within a few days.
I tested this with genuine Scotch(tm) tape (the slightly cloudy/translucent tape) and verified the tip-off. Tested with Sellotape(tm) (ordinary clear tape) and no such accelerated fading was observed.

You might experiment with different brands/types of sticky-tape and see which work.


---------------------------------


Extra:
If you like thermal experiments, and don't mind spending £16, you might like to buy a thermochromic liquid crystal sheet to play with...
http://www.edmundoptics.com/onlinecatalog/displayproduct.cfm?productID=1642&search=1
(I suggest the 25-30C one is best - but it depends a bit on the ambient temperature in your house/office, you normally want one that starts changing colour just slightly above ambient.)
You can leave a hand-print on a wooden desk and "reveal" it several seconds later with the sheet :-)
Rest the sheet against you computer-screen or other widgets to "see" the hotspots.
Check the product warning though, and don't heat these sheets above 60 degrees Celcius or so.

Not quite as much fun as a £15000 FLIR camera, but much more affordable!
Title: What's your kitchen science?
Post by: neilep on 13/06/2008 23:30:00
MAKE LIGHTNING IN YOUR MOUTH [ Invalid Attachment ]


What Ewe Need:

    * Wint-O-Green or Pep-O-Mint lifesavers
    * dark room
    * mirror

What Ewe Do:


Go to a really dark room and stand in front of the mirror. Wait a few minutes until your eyes get accustomed to the darkness.

Put a Wint-O-Green or a Pep-O-Mint lifesaver in your mouth.

While keeping your mouth open, break the lifesaver up with your teeth and look for sparks. If ewe do it right, ewe should see bluish flashes of light.

EXPLANATION:


Why does this happen? When ewe break the lifesaver apart, you’re breaking apart sugars inside the candy. The sugars release little electrical charges in the air. These charges attract the oppositely charged nitrogen in the air. When the two meet, they react in a tiny spark that ewe can see.
Title: What's your kitchen science?
Post by: Karen W. on 14/06/2008 06:28:51
That sounds like the same principal as the sugar cube experiment...Is it?? Kind of cool cause its in your mouth though!
Title: What's your kitchen science?
Post by: paul.fr on 15/06/2008 15:42:21
That sounds like the same principal as the sugar cube experiment...Is it?? Kind of cool cause its in your mouth though!

Why don't you post it karen, then we can see.
Title: What's your kitchen science?
Post by: Karen W. on 17/06/2008 08:42:05
I do believe it was your experiment from the start of this thread... The one where you go into a very dark room with sugar cubes and a pair of pliers. You wait for I think you said two minutes and then your eyes have adjusted to the light.. then you begin breaking the sugar cubes with the pliers.. I believe this is the one we sent home with the kids who were afraid to stay in the dark to see it. We hoped they would be less scared to do it with their folks! LOL
Title: What's your kitchen science?
Post by: paul.fr on 18/06/2008 16:57:08
Karen, you are correct but i don't think i did that one, i think it was done by Dave on the show with a pair of plyers. Then again i do not have the memory of a goldfish!
Title: What's your kitchen science?
Post by: paul.fr on 18/06/2008 16:58:37
What you need

Two (glass) milk bottles
matches or lighter
a piece of thick cord or shoe lace a few inches long


What you do

Put one of the milk bottles in the fridge for 10 minutes or so and the other bottle in a pan of very hot water.
After the time is up, Take the cord, light one end and drop it in to the cold bottle. Now turn the warm bottle upside down and place it on top of the cold bottle. Both bottles should have their open end joining.

What happens?

Now turn the bottles upside down.

What happens?


Explanation

First off, the smoke from the lit cord should have remained in the cold (bottom) bottle. When you turned the bottles upside down the smoke should have dropped in to the bottom bottle, but why?

In the first instance the smoke is held down by the heavy cold air, then when you turn the bottles upside down the cold and heavier air drops down in to the bottom bottle and again keeps the smoke there. The warm air is push up in to the top bottle because warm air is lighter.

Please use caution around matches and hot water.
Title: What's your kitchen science?
Post by: Karen W. on 19/06/2008 18:34:04
Karen, you are correct but i don't think i did that one, i think it was done by Dave on the show with a pair of plyers. Then again i do not have the memory of a goldfish!

Thanks Paul.. I know I got it off here!LOL
Title: What's your kitchen science?
Post by: Karen W. on 20/06/2008 12:04:16
Here is a slime recipe we have used at the preschool. We got it from the internet way back.. but I do not have the site..(Sorry) Its fun stuff Kids and adults alike like it! try the options they are cool too!

Try this one:

SLIME RECIPE

1/4 cup White Glue
1 1/4 cup Water, divided
1 tbsp. Borax - found in the laundry detergent aisle of your grocery store
Food Coloring

Borax is available in the laundry section of your local grocery store. Add 1 tbsp. Borax to one cup of warm water. Stir until completely dissolved.

Make a 50% water 50% white glue solution. Take 1/4 cup of each and mix thoroughly.

In a ziploc bag, add equal parts of the borax solution to equal parts of the glue solution. (Half cup of each will make a cup of slime.)

Add a couple drops of food coloring. Seal bag and knead the mixture.

If slime is too sticky, add a little more borax. If slime is too slippery, add a little more white glue solution.

Variations:

Less rubbery & more transparent slime: Try a 4% solution of polyvinyl alcohol instead of the glue mixture.

Different Consistencies: Add shaving cream or baby powder to the mixture

Glow in the Dark Slime: Add several drops of glow-in-the-dark paint during mixing.



Title: What's your kitchen science?
Post by: paul.fr on 23/06/2008 09:13:16
What you need

Cloth bag or a non-transparent container
Marker pen
Notepad
Calculator (optional)
Template of ‘Forty Fine Fish'
Coloured card or paper
Scissors
A friend

What you do

Draw and cut out 'Forty Fine Fish', preferably on coloured card.

Ask your friend to secretly count out a number of fish tokens and place them into the container or bag. To make it more of a challenge, ask them to make it any number higher than 20.

Now it's time to go fishing. To get an estimate of the number of fish, you need to do several fishing trips:

    * On your first trip, pull ten fish out of the container and 'tag' them with a cross using your marker pen before returning them
    * On your second trip, shake the container then pull out another ten fish without looking. Count how many of those fish are marked with the cross and write down the number, then return them to the container and mix them up
    * Now go fishing a third time, again recording the number of fish with crosses and returning them to the bag, mixing again
    * Go fishing one last time, writing down the number of fish you catch with crosses.

Add these 3 numbers and divide the result by 3 to get an average result. For example, if you counted 5 with crosses, then 3, and then 4, this equals 12. 12 divided by 3 equals 4.

The equation which estimates the total number of fish in the bag is:

    (Total number caught the first time x total number caught the second time) / average number caught with a cross

In our example, this would be (10 x 10) / 4. This equals 25, which is our total estimate.

Ask your friend for the actual number. Is your estimate close?


What's happening?

Estimates are guesses based on a small amount of information. Obviously we can't know the exact number of fish in a large area like a lake, so we need some way of getting a small amount of information and then making a guess based on it.

When you go fishing, you are taking a ‘sample' of the larger population. Samples usually represent the population you want to know more about. For example, half of a school might be boys and half girls. If you took a sample of the school, such as one class of students, it should also have about half boys and half girls. If you wanted your estimate to be more accurate, you could count two classes instead to get more numbers.

Your first fishing trip took one sample, and then tagged them all as caught. The second fishing trip counted the same number you caught the first time and compared it with the number of new (untagged) fish being caught. Obviously, if there aren't a lot of fish, you'll catch most of them again. But if there are large numbers of fish in the lake, you mightn't catch any tagged fish at all the second time.

Mark-and-recapture, also called tag-and-release, is a way of using samples to estimate the size of a population when you can't possibly count them all any other way.


Applications

Many organisms don't sit still long enough to be counted. People aren't all that different –it's difficult to study all of the people in a large area, which is why we do surveys. This means we study a small 'sample' part of a large number of people to provide us with an example of what other people might do as well.

We must be careful that our sample is similar to the whole population we want to study. Would it be accurate to study what breakfast cereal most people prefer if we only asked toddlers? Or what television shows all ages watch by only asking parents? Such is the case with our fish – it is only accurate if we can catch all types of fish we want to count. Imagine catching the fish using a net with holes big enough to let smaller fish through. Would this give us an accurate estimate?

"borrowed" from CSIRO.
either cut your own fish shapes out or use this template:
http://www.csiro.au/helix/sciencemail/activities/images/FortyFineFish.pdf
Title: What's your kitchen science?
Post by: paul.fr on 25/06/2008 19:28:54
What you need   


2 short glasses of water
A pie plate or tray
Liquid dish soap


What To Do

Put the first glass of water in the center of the pie plate, then slowly pour some water from the second glass into the first glass until it is very full and the water forms a dome above the rim of the first glass. Set the glass with less water aside.

Carefully stick your finger straight down through the dome of the water in the full glass and watch what happens.
Then put a small drop of dish soap on the tip of your finger and do the exact same thing - stick the finger with soap on it straight down through the dome of water.

what happens this time?


Explanation

Water is made up of lots of tiny molecules. The molecules are attracted to each other and stick together. The molecules on the very top of the water stick together very closely to make a force called surface tension. Surface tension is what caused the water to rise up above the rim of the glass in the experiment - the water molecules stuck together to make a dome instead of spilling over the side. Why didn't the dome break when you stuck your finger through it? Why didn't the water spill over the glass? Well, the surface tension was strong enough that it just went around your finger. The water molecules still stuck to each other and nothing spilled! What happened when you put your soapy finger into the water? The soap on your finger broke the water's surface tension and some of the water molecules didn't stick to each other any more and they were pushed out of the glass!

The force of surface tension also creates bubbles. In plain water, the surface tension is strong and the water might make some bubbles, but they will not last very long and they will be very small, because the other molecules in the water will pull on the bubbles and flatten them. Soap needs to be mixed with the water to make bubbles that can float through the air. When you add soap, the water becomes flexible, sort of like elastic, and it can hold the shape of a bubble when air is blown into it.
Title: What's your kitchen science?
Post by: paul.fr on 26/06/2008 09:21:02
What You Need

Liquid dish soap
Distilled water (tap water is okay, but distilled water makes the best bubbles)
2 clean containers with lids
glycerin or light corn syrup
Measuring cup
Mixing spoon
A plastic pipet (cut off the closed end to make a bubble blower) or a drinking straw
Tape and a marker


What you Do



Homemade bubble blowerMeasure 6 cups of water into one container, then pour 1 cup of dish soap into the water and slowly stir it until the soap is mixed in. Try not to let foam or bubbles form while you stir.
Once the soap and water are mixed, go outside to test it. Dip the cut end of your bubble blower into the solution and let the extra drip off. Blow through the narrow end to make bubbles. Do you get a lot of bubbles? How big are they? How long do they last before they pop?

pour half of the bubble solution into the other container. Put a piece of tape on the outside of the new container. Use the marker to label it "Super Bubbles."
Measure 1 tablespoon of glycerin or 1/4 cup of corn syrup and add it to the "Super Bubbles" container. Stir the solution until it is mixed together.
Dip your blower or straw into the new bubble solution and blow. Are these bubbles different from the plain soap and water bubbles? Are they bigger or smaller? Do they last longer or pop faster? Can you blow a really big bubble?

To make even better bubbles, put the lid on the container and let your super bubble solution sit overnight. You can add glycerin or corn syrup to the other container to make those bubbles better, too. (Note: If you used "Ultra" dish soap, double the amount of glycerin or corn syrup.).


Explanation

The first bubble solution was just soap and water. As you learned from the Surface Tension experiment (above), soap helps bubbles form. You probably got some small bubbles that didn't last very long from the soap and water. Then you added glycerin or corn syrup to the soap and water and probably noticed that the bubbles you blew were stronger and better than before. Did they last longer? Were they bigger? The glycerin or corn syrup mixes with the soap to make it thicker. When the water that is trapped between the layers of soap in a bubble evaporates (or dries up), the bubble will pop! The thicker skin of the glycerin bubble keeps the water from evaporating as quickly. You can probably also blow a much bigger bubble with the second bubble solution that you made than with the plain soap and water one. Adding glycerin or corn syrup makes bubbles stronger and helps them last longer. It makes super bubbles! 
Title: What's your kitchen science?
Post by: paul.fr on 27/06/2008 14:04:49
What you need


the above bubble solution
the lid from the container
a straw
some objects with pointed ends.



What you do


Set the lid on the table so that the part with the lip is facing up. Fill the lid with bubble solution. Dip your straw into the bubble solution container so that it is wet half way up the straw. Touch the straw to the
lid and blow a bubble on the lid. Slowly pull the straw all the way out of the bubble.

Now dip the pointed end of your scissors (or any pointy object) into the container of bubble solution. Make sure they are completely wet. Poke the scissors through the wall of your bubble. Watch what happens. Try it again with other pointed objects, just make sure anything you touch to the bubble is wet. Can you stick your finger through the bubble?



What's Happening?


Stick an object through a bubble!You should have been able to push the scissors through the wall of the bubble without popping it! When something wet touches a bubble, it doesn't poke a hole in the wall of the bubble, it just slides through and the bubble forms right around it. The bubble solution on the scissors filled in the hole that would have been made. If you try poking dry scissors through your bubble, you will see it pop instantly! (If it popped when you put the wet scissors in, something was probably too dry. Try it again and make sure anything that touches the bubble is completely wet with bubble solution.) For another trick, get one hand completely wet in the bubble solution then use the other hand to hold your bubble blower and blow a big bubble in the palm of your wet hand.
Title: What's your kitchen science?
Post by: paul.fr on 28/06/2008 01:20:00
If you take two sheets of clear glass or plastic separated by about one-half inch, soak them in soapy solution and then blow bubbles between the sheets, you will get many bubble walls. If you look closely, you will notice that all of the vertices where three bubble walls meet (and there are always three,) form 120 degree angles. If your bubbles are of uniform size, you will notice that the cells form hexagons and start to look much like the cells of a beehive. Bees, like bubbles, try to be as efficient as possible when making the comb. They want to use the minimum possible amount of wax to get the job done. Hexagonal cells are the ticket.

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When one bubble meets with another, the resulting union is always one of total sharing and compromise. Since bubbles always try to minimize surface area two bubbles will merge to share a common wall. If the bubbles are the same size as the bubbles to the left, this wall will be flat. If the bubbles are different sized, the smaller bubble, which always has a higher internal pressure, will bulge into the larger bubble.

 [ Invalid Attachment ]

Regardless of their relative sizes, the bubbles will meet the common wall at an angle of 120 degrees. All three bubbles meet at the center at an angle of 120 degrees. Although the mathematics to prove this are beyond me, the 120 degree rule always holds, even with complex bubble collections like a foam

 [ Invalid Attachment ]
Title: What's your kitchen science?
Post by: paul.fr on 28/06/2008 01:33:19
some bubble facts.

What Are Bubbles?

Bubbles are pockets of soap and water that are filled with air. When soap and water are mixed together and air is blown into the mixture, the soap forms a thin skin or wall and traps the air, creating a bubble. Soap bubbles are not the only kind of bubbles. You can find bubbles in lots of liquids. You might see small bubbles in plain water, but they will always be in the water, or floating on the surface of the water, not floating through the air. There are bubbles in soda pop, too. The special thing about soap bubbles is that they can float freely in the air; they don't have to be touching water or another liquid like most bubbles do. Can you find other bubbles around your house? What about something that is round and filled with air like a bubble? (Some examples are balls, balloons, and bubble wrap.)

How does soap help make bubbles out of water? Soap makes the surface tension of water weaker than normal. It also forms a very thin skin that is more flexible than water. When air gets trapped under the surface of the mixture of soap and water, the flexible skin stretches into a sphere shape (round like a ball), making a bubble! You can see the flexible skin that forms a bubble by dipping a bubble wand into some bubble solution. When you pull it out, the hole will be filled with a stretchable skin of liquid. If you blow gently on the skin, you'll blow a bubble!

What Happens to Bubbles?

Since bubbles are made from soap and water, they can only last as long as the water lasts. In dry air, water evaporates - it is soaked up by the dry air around the bubble and the skin of the bubble gets thinner and thinner until it finally pops! Evaporation isn't the only thing that pops bubbles. Anything dry can pop them. When a bubble floats through the air and lands on your finger, on a blade of dry grass, the wall of your house, or your pet's fur, the bubble will pop. When something sharp and dry touches the bubble, it pokes a hole in the bubble's skin, all the air goes out of it, and the bubble disappears! To learn how to touch a bubble without popping it, do Trick 2 in the Bubble Tricks experiment.

Why Are Bubbles Round?

Bubbles that float in the air and are not attached to anything are always round because the thin wall of soap is pulling in while the air inside of it is pushing out. A bubble always tries to take up the smallest amount of space and hold the most air that it possibly can. A sphere, the round ball-shape of a bubble, is the best way to take up a little space and hold a lot of air. Even when a bubble starts out as a square or another shape, like in Trick 1 from the Bubble Tricks experiment, it will always turn into a round sphere as soon as it floats away into the air. A square bubble would take up more space than a round one.

Lots of bubblesThere are a few times when bubbles are not round. Sometimes the wind blows them into different shapes. When bubbles are surrounded by lots of other bubbles, the ones in the middle get squished into other shapes, like squares or hexagons (shapes with six sides). Try blowing a lot of bubbles right next to each other in a shallow container and see if there are any that are not round. If you pop the bubbles on the outside, the ones on the inside will not be squished anymore and they will push back out to round bubbles again!
Title: What's your kitchen science?
Post by: Andrew K Fletcher on 30/06/2008 09:01:53
Comments welcomed.
Video

What You Need:

2 litres of water 2 kilos of granulated sugar, large saucepan and supervision is a must because boiling anything on a cooker is dangerous and boiling syrup will cause severe burns if it comes in contact with the skin.

Scale down to 1 k of sugar and 1 litre of water in a smaller pan.

Add water and all of the sugar to the saucepan and begin to heat it.

Observe closely how the denser fluid at the bottom of the pan behaves as the heat begins to motivate the syrup. At the same time observe the vapour bubbles and the rapidly agitating syrup below the surface.

Adding heat to the water and sugar crystals accelerates the dissolving of the sugar creating a very dense solution. The surface of the syrup does not boil, yet below the surface about half way down the saucepan is clearly boiling and if you look very close you can see lots of large and small gas bubbles forming and rising as you would expect them to do. However if you study what is happening you will see that the surface of the syrup remains unbroken and shows little if any motion while below the surface it is completely different and actively bubbling and boiling.

So what do you think is happening?

I suspect that a flow and return circulation is operating in the lower active level of the syrup where the heat is causing the fluid to form gas and rise but in doing so is generating a return flow from the cooler water causing the rotation of the syrup rather than it reaching the surface and disrupting the stagnant state. The dense syrup is acted upon by gravity and the heat at the base of the pan changes the density of the syrup causing it to rise, where it meets the lower part of the cooler surface less dense syrup and returns back to the base of the pan taking with it the vapour bubbles and preventing them from reaching the surface of the liquid.

Before all of the sugar has turned into clear liquid stir the solution with a wooden spoon and let it return back to the un-agitated state and you should see the lower level behave as before and the surface layer remain once again still.

Eventually the surface syrup heats up and the liquid boils as one would expect a liquid to boil. Yet when another Kilo of sugar is added to the now boiling syrup the same low surface flow happens again and the surface of the liquid stagnates until all the sugar has dissolved and the liquid is boiling in the normal manor.

This is a fascinating experiment that requires supervision as boiling syrup is very dangerous. The sugar looks like clouds viewed from an aircraft for a while.

What does it tell us?

Having been working on a density flow theory in plants, trees, animals and humans that generates circulation by density changes occurring in the fluids due to evaporation, the boiling syrup experiment shows how powerful this gravity driven flow really is. It also shows how density changes at the surface of the ocean due to evaporation and the resulting increases in density of surface water generate an underwater river that drives the Atlantic Conveyor system, a river thought to be larger than all of the combined rivers in the world that powers the world’s weather.

But does it also tell us something about the nature of gravity?

Andrew K Fletcher

You may also be interested in my other density videos on You Tube and if you like them please leave a comment and rate them :)
Title: What's your kitchen science?
Post by: paul.fr on 03/07/2008 16:41:18
What you need


a key
a saucer or plastic bowl large enough to contain the silver object
a cardboard box large enough to cover the silver object
Something made of silver or something silver plated.  It should be something that is easy to polish, as you will have to polish it twice.  Flat surfaces work much better, so a spoon or knife will work very well. The experiment will not damage the silver, but I suggest that you avoid ornate pieces with lots of hard to polish areas.
Tincture of Iodine (with the medical supplies at your local store) 


What you do


Polish the silver until it is very shiny.  In a dimly lighted area, place the silver object on a saucer or in a plastic bowl.  Carefully pour some iodine over the silver and then cover it with a box, to keep out as much light as possible.  Wait for about two minutes.

Remove the cover and shine a very bright light, such as a bright lamp onto the silver.  Hold the light there for about four minutes.  Then remove the bright light and rinse the iodine from the key and the silver.  Remove the key and look at the surface of the silver.  You will see the image of the key.

Polishing will remove the resultant tarnish from the silver, with no harm done.


Explanation:


The iodine reacted with the silver to form a chemical called silver iodide.  Silver iodide is sensitive to light.  In bright light, it change into silver oxide, a dark colored chemical.  That reaction does not happen under the key, where the light does not reach, so that part of the silve stays light colored.  Together, this produces a negative image of the key.

This is basically the same thing that happens in a photograph.  The parts of the film that are hit by light are changed, while the parts that remain in the dark are not.  This produces a negative image.  Shining a light through the negative onto treated paper gives you a negative image of the negative, in other words a positive image.

Warning!  Iodine is toxic and will stain skin and clothing.
Title: What's your kitchen science?
Post by: neilep on 03/07/2008 18:19:42
BEND WATER  [ Invalid Attachment ]

What You Need:
(go on...go and get this...beware..some combs bite !)

    * comb
    * a piece of wool, nylon or fur

What you do:....do it....do it now !!

Rub a comb quickly against the piece of wool, nylon or fur for about a minute

Hold the comb near a trickle of water from a faucet.

What Should happen:

The charged comb should attract the water toward it.



Why does this happen?
(I'll tell ya shall I ?...yes..yes I will !)

 By rubbing the comb, you’re covering it with little negative charges. The negative charges are attracted to the positive charges against the water.




Warning: Water may inadvertently splash on ewe...and if ewe're like me..(who bathes just once a year)...then you must be warned that a part of you may accidentally become clean !!
Title: What's your kitchen science?
Post by: paul.fr on 04/07/2008 22:54:08
What you need


Portable ultraviolet light
Bottle of tonic water (unopened)
Drinking glass, clear
Darkened room


What you do


Open the tonic water and pour some into a large, clear drinking glass. Place a white sheet or poster board behind the glass to create a white background. Turn off all the lights and completely darken the room. Turn on the black light and shine it on the tonic water.

what happened?


Explanation

The black light gives off UV light which is a higher energy light than visible light and the human eye is not able to see it well. So, if ultraviolet light is virtually invisible, how can the tonic water glow so brightly? The tonic water's color under the UV black light is fluorescent-blue because it contains quinine, a substance that changes when it absorbs UV light. When the black light shines on the tonic water, the tonic water absorbs the light and excites the electrons. Since the electrons naturally want to return to their original relaxed state, they give off energy that has a wavelength in the blue part of the visible spectrum. That's why the tonic water has an eerie blue glow in the presence of ultraviolet light!
Title: What's your kitchen science?
Post by: Anastasia.fr.1 on 05/07/2008 18:59:27
What you need

A piece of paper
A pencil
A drinking glass.
A jug of water.


What you do


Fold the sheet of paper in half and draw an arrow in the middle of one side.

Stand the folded paper on a table with the arrow pointing left. place the empty glass in frount of it. now fill the glass with water. now slowly move the piece of paper away from the glass, you should be looking though the glass as you do this.

what happens to the arrow [?] [?] [?]

I dont know why this happens but grahem does [8D]
 http://www.thenakedscientists.com/forum/index.php?topic=15658.0

By  Anastasia-marie
Title: What's your kitchen science?
Post by: Anastasia.fr.1 on 05/07/2008 20:57:43
It's not a science experiment, but it's fun to do.

think of a number 1-10
double it
add 14
divide by 2
take away the first number you thought of

i bet your left with the number 7

MAGIC MAGIC
by Anastasia
Title: What's your kitchen science?
Post by: Anastasia.fr.1 on 06/07/2008 10:32:17
You will need


Template (http://www.csiro.au/helix/sciencemail/activities/images/AmesRoomTemplate.pdf)
Photocopier (optional)
Large sheet of card – the bigger the better
Cutting blade or scissors
Ruler
Coloured card, pens and pencils
Glue and/or sticky tape


What to do
Download this Template (http://www.csiro.au/helix/sciencemail/activities/images/AmesRoomTemplate.pdf)
 and print it out.

The bigger the model is, the better the illusion works. There are two ways you can make the template bigger if you wish:

Use a photocopier to blow the image up onto one or more sheets of A3 paper.
Measure the lines on the template and multiply them all by the same number to come up with a larger scale diagram. Use a protractor to measure the angles of each part of the template. Use a ruler to draw this new template onto your card.
Cut out the template, then trace it onto the card.

Notice that one panel is decorated with a distorted chequered pattern – use pens or coloured card to copy this pattern as precisely as possible, or better yet, cut the pattern out of the template paper and glue it in place onto the card.

Decorate the rest of the panels as if it is a room, paying attention to how one end of each panel is narrower than the other end. So, if you draw a window or a picture, it must also have one end narrower than the other.

Cut the model out of the card. Remember to also cut out the two shapes labelled ‘x’; one is so you can reach into the model, and the smaller hole is for you to look into the model.

Fold the model into a box shape and glue or tape the tabs in place on the outside.

Take two small objects roughly the same size (e.g. two toy cars) and place one in each corner of the box opposite the small hole.

Peek through the hole. How do the objects look?

What’s happening?


This model is called an ‘Ames room’, named after the ophthalmologist Adelbert Ames who first created one. If the model is neat enough, the room should look fairly normal when peering through the hole. One of the objects should look smaller than the other, however, even though they are the same size.

We use a number of clues in our visual field to determine the size of an object. For example, the slightly different positions of our two eyes on the front of our heads mean each eye sees a slightly different picture. Combined, these two images give objects depth, but can also give clues about how far away they are.

A more important clue, however, comes from the assumptions our brain makes about the room. It is difficult for your brain to tell whether the far wall is perpendicular (at right angles) to your line of sight, or slanted away. However, there is a rule your brain is familiar with – two straight lines coming together to a point indicates distance. Think about how the parallel lines of a railway track seem to converge in the distance.

Using that rule, your brain determines the room is ‘normal’, which means both objects are the same distance away when they really aren’t. The conclusion it comes to? One object is actually smaller and close by rather than far off in the distance.

Applications


Ever wondered how Gandalf was made to look so much bigger than the hobbits in The Lord of the Rings? No, they’re not using shorter or taller actors – they are all roughly the same height in real life. While computer effects could be used, this can be expensive.

A cheaper method for film makers is to use effects such as those used in the Ames room to make things seem bigger or smaller. While the set looks normal on film, in real life it has been built using odd angles. When one actor stands on one side of the room with another actor opposite them, they look as if they are standing side-by-side, where really one is standing further in the distance, making them look small.

written by CSIRO.

Title: What's your kitchen science?
Post by: paul.fr on 10/07/2008 14:20:07
What you need


a pie pan or shallow bowl
a candle
a glass jar large enough to hold the lit candle
water

 
What you do


Light the candle and let a few drops of melted wax fall on the middle of the pan.  Place the bottom of the candle into this wax to secure it in place.  Carefully add about an inch of water to the pan.  Relight the candle if it has gone out, and place the jar over it.  Watch carefully.  After a minute or so, the candle will go out, and the water will rise up into the jar.

 
Explanation

This shows that the candle has burned up the oxygen, and the water has risen into the jar to take its place, right?  WRONG!!!!!   If you watch carefully, you will see why is it wrong.  When you first place the jar over the candle, air bubbles OUT of the jar.  If you are slow about placing the jar over the candle, you might not notice this, but if you cover the candle in one quick motion, you will see the air bubbling out.   Once the candle goes out, the water begins to rise in jar. 

 
Now, lets think about that.  If the water was rising because the oxygen was burned up, it would rise while the candle was burning and stop as soon as the flame went out.  Is that what you saw?  No.  Then what really did happen?

 
As the candle burns, it is heating the air in the jar, causing it to expand.  This causes the bubbles that leave the jar.  The candle is burning oxygen, but the oxygen does not vanish.  It combines with carbon from the burning wax to form carbon dioxide, another gas that also takes up space. 

 
When the candle goes out, the air begins to cool, which causes it to contract.  As the air gets smaller, the water rises into the jar. 

Written by Robert Krampf (http://www.krampf.com)
 

Title: What's your kitchen science?
Post by: paul.fr on 20/07/2008 15:55:23
What you need


Tap water
A glass or clear beaker


What you do

Fill the glass with tap water and put it somewhere it will not be disturbed, go to bed and examine the glass in the morning.
What happened?


Explanation:

You should have noticed that the water in the glass had bubbles, the bubbles should be on the side of the glass. But how did the bubbles get in to still tap water?
Well I have no idea, but luckilly for us, Ian does know.
Where did the bubbles come from in my glass of water? (http://www.thenakedscientists.com/forum/index.php?topic=15980.0)
Title: What's your kitchen science?
Post by: paul.fr on 23/07/2008 15:42:59
What You need


A4 sheet of paper
Scissors
Sticky tape


What you do


Fold the A4 paper lengthways into thirds. Use the creases to neatly cut one-third of the sheet away. You will be left with a sheet that is now two-thirds the original size and creased into halves.

Take one of the long edges of the sheet and make a fold about 1 cm wide. Run a fingernail along the crease to press it down firmly.

Repeat this process, folding the edge over four or five times, until you reach the middle crease.

Turn the sheet over and grip the shorter ends of the sheet, with one end in each hand. Find the edge of a desk or the back of a chair, and rub the folded side of the sheet back and forth over the edge. After a few rubs, you’ll notice the sheet will start to curl.

Continue to roll the sheet into a circle, tucking one edge into the fold of the other. Use sticky tape to secure the edges into place.

To throw: pick up the tube as if it is a can of soft drink, with the folded side at the bottom. Find a large, open space and aim the folded side of the tube in the direction you want the tube to fly. Swing your arm back and throw it.

Do it again, this time remembering to spin it with your fingers as you release it.

With practice, your paper ring should fly quite a long distance.

Explanation:


The paper ring flies for much the same reason a normal paper plane does.

Many forces come into play – thrust (propelling the plane forward) is opposed by drag (the resistance of the paper against the surrounding air). Throwing the ring gives it thrust.

There is also gravity pulling the plane’s mass down. But, the ring doesn’t fall because the shape of the wing is special – as air flows close to the surface, some of it is slowed down by the resistance against the wing. As this happens differently on the outside than it does on the inside, it creates a difference in how the air pushes against the paper on each side. This is called ‘lift’, and helps increase the force under the ring which keeps it from falling due to gravity…at least until the thrust runs out.

One reason the ring eventually falls is because of its unstable flight path. The ring will naturally want twist away from where you throw it, which takes away some of its thrust. By spinning it, you give the paper ‘angular momentum’. It acts like a gyroscope, making it more stable as it flies and allowing it to get more out of the thrust.
Title: What's your kitchen science?
Post by: neilep on 08/09/2008 20:29:31
Posted this as a genuine question but it also serves as a contribution to the FANTASTIC thread !

Dear Peeps Who Sing This !

"Roll me over lay me down and do it again
Roll me over in the clover, roll me over lay me down and do it again"


As a sheepy, I of course indulge in consuming fizzy drinks !


See my fizzy can of pop ?

 [ Invalid Attachment ]

Hmmm...what delicious treat resides inside I wonder ?

Now then, If I take another one....shake it hard and then place both of them at the top of a slight incline...the shaken one will roll down slower !!


Why's that then ? Why does the non shaken one roll faster ?


I don't know.. I simply do not have a freaking clue !!

Oh how I wish I knew !...will someone who knows this tell me ?

Thanks

Hugs and shmishes


Neil
Soda Pop Problem Asker

xxxxxxxxxxxxxxxxxxxxxxxxxxxx

mwah mwah mwah mwah !!!
Title: What's your kitchen science?
Post by: Cameron Lapworth on 09/09/2008 01:38:21
Hi,
   Another one I've done with my year 8's in science is building an electric motor with a magnet battery and some cardboard and a coil of wire. very impressive you can really get some speed up.  I've found a link to something similar  here.  try it it's great.  http://www.pbs.org/weta/roughscience/discover/powerplant.html#motor

Cameron
Title: What's your kitchen science?
Post by: paul.fr on 05/12/2008 22:48:36
What you need

lemon Juice
A piece of Aluminium.
A cup


What you do

Part fill the cup with the lemon juice and then  put your piece of aluminium in to the cup. What happens? Why?

Explanation

You should see bubbles of Hydrogen (H2) gas, but why? Well this clever chap has the answer (http://www.thenakedscientists.com/forum/index.php?topic=18457.0)
Title: What's your kitchen science?
Post by: paul.fr on 05/12/2008 22:58:57
What you need

A length of ribbon
A pair of scissers


What you do

Lay the ribbon on a flat surface and  run the flat blade of the scissors along the ribbon.

Explanation

The ribbon should start to curl, this is because one side of the ribbon becomes a bit longer than the other, the ribbon tends to curl in a direction that puts the longer side on the outside of the curl and the shorter side inside. Which is what  these people said. (http://www.thenakedscientists.com/forum/index.php?topic=18565.msg208268#msg208268)
Title: What's your kitchen science?
Post by: Anastasia.fr.1 on 05/01/2009 04:49:06
as written by Robert Krampf:

y Grandmother is going to have her 103rd birthday this month. I have been thinking about how much the world has changed during her life. Imagine only having fruits and vegetables when they were in season. Imagine no computers, no television, no air conditioning, no refrigerators. This time we are going to step back in time a bit, and make our own butter.

To try this delicious treat, you will need:
a small container of heavy whipping cream
a glass of water that is half full

If you have never made butter, these instructions may sound strange, but trust me, it works wonderfully. The first thing to do is to let the cream sit on the counter, at room temperature, for about 12 hours. I put it out on the counter after supper, and I had freshly made butter on my toast the next morning.

After letting the cream sit, pour it into the glass jar. Don't worry if it has a slightly sour smell. Put the lid on the jar. Now we have to shake the jar, but we don't want to just start shaking it wildly. We want to watch what is happening. Give it one good hard shake about once every second. Watch carefully. For the first few minutes, not much will happen. Then suddenly, you will feel something solid hit the jar when you shake it. Look inside and you will see a large lump of butter. Give it a few more hard jolts and your butter should be ready.

Open the jar and look carefully. Around the butter is a thin, white liquid, which is commonly known as buttermilk. If you have ever had buttermilk biscuits, this is what they are made with. Pour off the buttermilk and add some cold water to the jar. Swirl it around a bit and then pour it off. Repeat this a few times, until the water remains clear. Drain all the water and put the lump of butter into a small bowl.

At this point, you have sweet cream butter, which is wonderful on hot bread or fresh biscuits. If you prefer salted butter, simply sprinkle some salt into the butter and stir it in. At this point, treat the butter just as you would the butter you get from the store.

That was quite yummy, but how and why did it work? First, we have to know a bit about milk. If you have ever been lucky enough to have milk fresh from the cow, you know that if you let it sit for a while, the cream floats to the top. That is because milk contains lots of tiny globules of milk fat, each surrounded by a thin membrane. Imagine tiny balloons filled with butter instead of air. Because the milk fat (butter) is lighter than the liquid, they tend to float. The cream that rises to the top is really a very high concentration of these fat globules floating on the milk. The milk from the grocery does not do this because it has been homogenized, a process that makes the fat globules small enough to keep them mixed evenly in the milk.

We left the cream out of the refrigerator overnight for two reasons. First, it helps the fat in the globules to form crystals. These crystals will help to break the membrane when we shake the cream. Imagine a water balloon with shards of glass inside. One jolt would cause the glass to slice through the balloon. That is what we want to happen.

Letting the cream sit at room temperature does something else. It allows lactic acid bacteria to grow. We think of bacteria as a bad thing, but many of them are quite useful. These bacteria make the cream more acidic, which prevents the growth of harmful bacteria. They also produce chemicals that give the butter a stronger and richer flavor.

When you shake the cream, some of the globules slam into the glass and break open. Soon, the cream is filled with tiny globs of butter. As these tiny bits of butter bump into each other, they stick together. The lumps of butter get larger and larger, as more and more globules are ripped open. Very quickly, you have one large lump of butter and a small amount of liquid buttermilk. I was amazed at how little liquid was left once the butter formed.

You will probably notice that the color of your butter is more pale that the stuff you buy at the store. Some manufacturers add yellow color, but a lot depends on what the cows are eating. Cows that eat grass get lots of a chemical called carotene, which adds a yellow color to the butter.

The true test of your butter is a fresh, hot biscuit or some crusty French bread.

Have a wonder-filled week.
Title: What's your kitchen science?
Post by: paul.fr on 07/02/2009 13:22:55
Non-Newtonian Fluid on a Speaker Cone

Reader Jackson points us to an interesting video depicting non-newtonian fluid on a speaker cone. Basically, "corn starch is a shear thickening non-Newtonian fluid meaning that it becomes more viscous when it is disturbed -- when it's hit repeatedly by some thing like a speaker cone it forms weird tendrils." Video after the break.

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video here
http://www.techeblog.com/index.php/tech-gadget/non-newtonian-fluid-on-a-speaker-cone
Title: What's your kitchen science?
Post by: 112inky on 25/03/2009 04:56:31
not sure if this is the right section for this topic, but here goes.

We all love the kitchen science part of the show, but what are your favourite kitchen science experiments? Either those featured on the show / podcast, or ones you have done yourself?

Why not post them here, and let us all enjoy the wonder of experimentation.

Just post the items you need, and how to conduct the experiment. Like the kitchen science on the show, please do not post what the final result is. That way we will not lose some of the enjoyment of conducting the experiment.

If a member is unsure of his/her results they could always pm the poster.


OK, here is a simple on to start thins off. I have already posted this somewhere, and there was some doubt as to whether it worked. so why not try for yourself and then post one of your own:

What you need

2 cups
about 15 copper coins
salt
a nail
and vinegar

What you do

place your copper coins in your cup and cover them with salt. Then pour in some of your vinegar, to about 1cm above the top coin.

leave for half to one hour, then drain the solution in to the other cup. At this point you will have shiny copper coins, but that is not the whole experiment.

With just the solution in the second cup, drop your nail in to it and wait another half to one hour.

What happens to the nail?

topic link

Why does vinegar make copper coins all pink and shiny? http://www.thenakedscientists.com/forum/index.php?topic=6240.0




hey.. its a wonderful idea.. and i am gonna try it out on my own.... i am never allowed inside the kitchen for the reason i would mess it up....but.. i am gonna try this for sure..
Title: What's your kitchen science?
Post by: 112inky on 26/03/2009 04:20:20
What you need

A fat/chunky felt tip pen
A woolen cloth or jumer
A plate
Salt and Papper


What you do

Sprinkle some salt an pepper on to the plate. Then get your woolen cloth or jumper and rub it very hard along your felt tip pen for about 1 minute.

stop rubbing, discard the cloth/jumper and move the pen slowly over the plate.

What happens?


Hi i tried it.. but nothing happens... what would be the problem????
Title: What's your kitchen science?
Post by: Karen W. on 29/03/2009 03:11:17
How to blow out a candle with sound waves!


What you need:

1 cardboard tube

Some thin plastic wrap or recycled plastic bag

Scissors

Scotch tape

1 Birthday candle

1  small dish

Sand or soil either one will do.


1. First you cover each end of the tube with some plastic wrap.. making sure it is snug and tight across the ends. Tape the plastic on snuggly.

2. Secondly you use your scissors to make a very small hole in the plastic at only one end of the tube.

3. Thirdly You then put some of your dirt or soil in the dish and stand your candle up in the dirt or sand. Use enough to hold your candle firmly up.

4. Next, if you are very young ask an adult to light the candle for you.

5.Now hold the end of your tube or "sound cannon" with the hole about 1 inch from the candle flame.

6. Next you should tap the end of the tube with your finger against the plastic wrap at the other end.Making sure you are still 1 inch from your flame....

What happens?

If you do it right it will sound as if you have tapped a small drum. The tapping of the plastic will then  cause the plastic to vibrate pushing the air inside your tube down and out through the tiny hole in the plastic creating enough force to blow out your candle!


[diagram=441_0]
Title: What's your kitchen science?
Post by: daveshorts on 14/04/2009 18:06:59
This is actually more to do with smoke rings than sound. Have a look at
http://www.thenakedscientists.com/HTML/content/kitchenscience/exp/vortex-cannon/
for more info
Title: What's your kitchen science?
Post by: Karen W. on 14/04/2009 20:38:13
thats interesting..I was trying to remember from the experiment how it wa done and  i am positive t wasa sound cannon... but perhaps my book is too old.. It was a science experiment book I did things with the kids with.. thanks Dave next week I will get te book out and copy the pages and see if It is just my memory or a too old and inaccurate book...I have the bookhandy.. bu have to wait for my cable service to be back up... It will be down about a week...
 thanks for sharing!
Title: What's your kitchen science?
Post by: gurpal on 24/07/2009 19:53:11
how do you all come up with this stuff
Title: What's your kitchen science?
Post by: Chemistry4me on 25/07/2009 00:17:50
By using their minds, but mostly the internet [;D]
Title: What's your kitchen science?
Post by: wolfekeeper on 15/03/2010 00:52:44
I just did a fun experiment. I made 'hot ice'.

Basically what you do is take vinegar (I used sarson's distilled malt vinegar) and some baking soda (sodium bicarbonate) and react them together (lots of foam!) This makes sodium acetate and lots of CO2 which bubbles off.

You then take it and boil it down (it took hours and hours and the place stank with the smell of salt and vinegar crisps!)

Once you've boiled it down you can let it harden off, and it will go like a bit like plastic.

Once it's set you take it and heat it up to around 100C in some kind of container (I used a tin) and it goes like water, and (if it's not contaminated) it will stay like that down to room temperature.

If you then add a crystal of the solid sodium acetate then it very rapidly crystallises and generates lots of heat (it's used in hand warmers).

Overall, it's quite fun.

You can also buy sodium acetate premade, but where's the fun in that?
Title: What's your kitchen science?
Post by: abecai63 on 26/08/2010 20:43:29
how do you all come up with this stuff

I was wondering the same thing. You guys are pretty creative.
Title: What's your kitchen science?
Post by: daveshorts on 26/08/2010 21:16:46
Some I remember from childhood some i find in books, some from friends, some I invent, but most I find on the net. Though I often  tweak them a bit.
Title: What's your kitchen science?
Post by: Airthumbs on 26/06/2011 18:21:57
Aluminium Can Battery

After reading through some of the kitchen science stuff I feel that this idea is worthy of its own post and thats what I have done.  After posting it I saw this section and will endeavor to include a description of the Aluminium Can Battery.


What you need



1 Aluminium can
About 1 meter of conductive wire. (I used the outer sheath of a coaxial cable).
A sponge
Some paper tissue towling
Some saline water. (I used 2 teaspoons of salt mixed into about 300ml of water).
A can opener
Some sand paper
Scissors


What you do

Using the can opener remove the top of the can.  Make sure the inside is clean. Be careful here as the top of the can is very sharp so it might be best to wear protective gloves to prevent cutting yourself! Take the sand paper and lightly use it to rub the inside of the can.  This helps to maximize the surface area in  contact with the saline solution, I think :)
Cut the sponge down so it is about the same length of the can.  Then using the scissors cut down the middle of the sponge but not all the way through, you should now be able to open the sponge up as if it were a cob, bun, or even bap!
Place the coaxial cable inside the centre of the sponge with about 2cm sticking out from one end, close the sponge, with what you have left begin to wrap the wire around the outside of the sponge starting at the opposite end you have from where the wire is sticking out and working your way towards the end with the wire sticking out about 2cm. Keep making the coils around the outside of the sponge until you have used up all of it. The final end of the cable can be just tucked under one of the coils you have made to secure it in place.
Now take the paper toweling and carefully wrap this around the outside of the sponge and wire.  The idea of this is to prevent the wire from touching the inside of the can.  Now push the sponge inside the can until you are left with just the top of the sponge visible with wire sticking out from the centre.
Now you are ready to pour the saline solution into the can, do this slowly as it takes time for the sponge to absorb the water, keep going until you almost reach the top of the can.

And that's it. You just made a battery.

I will be experimenting with variations of, wire length and saline concentrations to see if I can find the most effective combinations to produce a higher voltage and/or duration of the battery.  They normally last about an hour.

Lets try and make a difference, spread the word..  [;D]  please let me know if you manage to get more then .18V, the video I saw they were getting about 1V, so I am not doing something right? 

Here is the link to the original video Can the Naked Scientists please make a better one?
Title: Re: What's your kitchen science?
Post by: nekS576 on 25/01/2019 14:54:47
anything!
Title: Whats your kitchen science
Post by: CharlesCably on 21/08/2020 16:16:00
the tortilla chips in your nachos look incredible  Howd you do them?  Fried in oil?
 
 I would have been happy with those chips, salted, and a beer
 
 Lee