Egg+in+a+Bottle

By: Nick Harloff **
 * E g g i n a B o t t l e !

**Materials:** -peeled hard-boiled egg (or soft-boiled) -flask or jar with opening slightly smaller than the egg -paper/lighter or very hot/cold liquid

** Procedure: ** **__Method 2__**
 * __Method 1__ **
 * 1) Light a piece of paper/splint on fire
 * 2) After a couple of seconds of burning, drop it into the bottle
 * 3) Set egg on top of bottle (small side down)
 * 4) When flame goes out, the egg will be pushed into the bottle
 * 1) Set the egg on the bottle (small side down)
 * 2) Run the bottle under very hot tap water
 * 3) Set bottle on top of a cool counter
 * 4) As bottle cools, the egg will be pushed into the bottle
 * __Method 3__ **
 * 1) Set the egg on the bottle (small side down)
 * 2) Immerse the bottle in a very cold liquid (ice water is recommended)
 * 3) The egg will still be pushed into the bottle as the container chills

**Explanation:** At the beginning of the demo the diameter of the egg is too big to fit into the opening. Also the air pressure inside and outside of the bottle are the same, so the only force acting upon the egg is gravity. But gravity it is not strong enough to pull the egg through. The only way it will work is if you make the pressure outside the bottle stronger than on the inside. This can be accomplished when you change the temperature of the air inside the bottle; you will thus change the pressure of the air inside the bottle. If there is a constant volume of air and you heat it, the pressure of the air increases. If you cool the air, the pressure decreases. If you can lower the pressure inside the bottle enough, the air pressure outside the bottle will push the egg into the container. When you drop burning paper into the bottle, the paper will burn until the oxygen or the paper is consumed. Combustion heats the air in the bottle, increasing the air pressure. The heated air pushes the egg out of the way, making it appear to jump on the mouth of the bottle. As the air cools, the egg settles down and seals the mouth of the bottle. Now there is less air in the bottle than when you started, so it exerts less pressure. When the temperature inside and outside the bottle is the same, there is enough positive pressure outside the bottle to push the egg inside. Heating the bottle produces the same result. The bottle and the air would be heated. Hot air then escapes from the bottle until the pressure both inside and outside the bottle is the same. As the bottle and air inside continue to cool, a pressure gradient builds, so the egg is pushed into the bottle.

**Neat Egg Facts:** - The ancient Egyptians buried eggs in all of their tombs. This was done as a symbol of resurrection and birth. - The ancient Greeks placed eggs on top of graves. When the Greeks took over ancient Israel, many Jews adopted this practice. Even to this very day, Jews place rocks on top of gravestones to signal that the grave has been visited and the loved one remembered (perhaps as a substitute for eggs).

**Works Citied:** Green, Joey. “ Egg in a Bottle. ” //Mad Scientist Experiments//. 2009. Copyscape. 16 January 2010. <[]> Helmenstine, Anne. “ The Power of Air Pressure. ” //Egg in a Bottle Demonstration//. New York Times Company. 16 January 2010. <[]>