[Karen W.]

Yummm!

[paul.fr]

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!

[neilep]

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.

[Seany]

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?

[paul.fr]

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.

[Seany]

Yah, I don't know what they're called..

EDIT: Oh its called a film canister!

[paul.fr]

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?

[Seany]

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)?

[paul.fr]

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"  [] does not hang over or fall in.

[Seany]

Ohh! Ok. And great, your on 1000 posts [] Just couldn't help realising. []

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..

[paul.fr]

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)]

[Seany]

Oh.. Does the coin just miraculously POP and fly out? []

Well.. I'm once again lazy to do this experiment. [] Will look on the web! []

[Seany]

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?

[Seany]

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?

[Seany]

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.

[paul.fr]

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

[paul.fr]

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

[neilep]

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

[Karen W.]

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!

[Seany]

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?