[paul.fr]

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?

[paul.fr]

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.



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?

[paul.fr]

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!

[paul.fr]

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?

[paul.fr]

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.



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

[paul.fr]

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!  [:-[]

[paul.fr]

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?

[paul.fr]

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!

[Batroost]

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...

[Batroost]

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).

[Batroost]

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.

[paul.fr]

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:



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

[paul.fr]

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):



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):



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."

[paul.fr]

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  []

[paul.fr]

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.

[paul.fr]

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?

[Batroost]

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.

[paul.fr]

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?
 

[paul.fr]

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/


 

[paul.fr]

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.