Egg in a Bottle

Want your friends to think your a genius?  Tell them you can make a hard-boiled egg squeeze through the opening of a Gatorade bottle in one piece, without touching it.  Then, follow the steps below.

What you need: a hard-boiled egg, deshelled; an empty Gatorade bottle; a strip of paper (~3 inches x 3 inches, rolled up); a match or lighter.

What to do:  Light the paper with the match or lighter and drop it into the Gatorade bottle.  Quickly take the egg and place it over the opening.  Watch as the egg is sucked into the bottle, all on its own.

How does it work?  Before you start, the pressure on the inside of the bottle and the outside of the bottle are the same.  When you drop the lit paper into the bottle, you heat the surrounding air, causing it to expand.  When you place the egg on the top of the bottle, the fire inside the bottle quickly uses up all of the oxygen and goes out.  At that point, the air in the bottle cools and contracts.  When this happens, the pressure outside the bottle is greater than the pressure inside the bottle.  This difference in pressure causes the egg to squeeze through the opening into the bottle.  Magic? No... Science!

BE CAREFUL performing this activity at home - it requires fire.  We recommend this activity for high schoolers and also recommend adult supervision.  Instead of a plastic Gatorade bottle, an old glass milk bottle is a great alternative.  Always use care when performing experiments that require open flame.  Thanks to Krishna Pabba of U.T. Arlington for contributing this demonstration to DISCUS.  Krishna credits information he obtained from a University of Wisconsin website for this activity.  It can be found here.  Also, another U.T. Arlington student, Patricia Wong, performed this activity and took a nice video, which can be found here.  Thanks Patricia.