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Egg in a Bottle
You will need:
- An empty milk bottle, or any other glass bottle or jar with an opening just smaller than the diameter of your hard boiled egg. It might help to grease the opening with a little vegetable oil or margarine
- A hard boiled egg with the shell removed (a partially inflated balloon may work better than an egg)
- A twist of scrap paper
- Matches
What to do:
Set light to the twist of scrap paper and rapidly put it in the bottle. As the paper burns, it heats up the air in the bottle, making it expand and become less dense than the air outside. Immediately put the egg in the opening of the bottle. As the paper burns, it uses up the available oxygen in the bottle, and eventually goes out. The air in the bottle then cools, and the resulting pressure difference between the outside and inside of the bottle sucks the egg into the bottle.
How do you get the egg back out again?!
Hold the bottle upside down (so that the egg is blocking the opening from the inside) and, sealing the opening with your mouth, blow into the bottle. This will push some extra air past the egg, the pressure inside the bottle will become greater than the pressure outside and the egg will be pushed out again.
How does this relate to the weather?
The large scale circulation of the atmosphere and oceans, and smaller scale weather systems, are all driven by pressure differences. Air, and water, will always tend to move from areas of high pressure to areas of lower pressure.