Getting the Egg into the Bottle

Illustrate the consequences of “accepting an invitation to do wrong.” Choose a large milk or juice bottle with a mouth just slightly smaller than a smoothly peeled hard boiled egg. Wrap a half piece of paper towel into a loose roll. Light the paper at its lower edge and drop it into the bottle. Immediately place the egg on the neck of the bottle.

As the fire heats the air inside the bottle, it expands, causing the pressure to increase inside the bottle. Notice that the egg bounces as air from inside the bottle rushes out. Eventually the air becomes so thin that it can no longer sustain combustion, and the flame goes out.

The air inside the bottle cools rapidly, and the water vapour produced by combustion condenses, causing a dramatic drop in pressure. Because the pressure inside the bottle is now much lower than the pressure outside, air outside the bottle pushes the egg into the bottle with a loud “pop.”

In this demonstration we are the egg. The fire represents the invitation to do wrong. Placing the egg in the neck of the bottle represents accepting an invitation to do wrong. And, becoming trapped in the bottle illustrates the consequences of doing wrong.

Getting the Egg out of the Bottle

Just as yielding to the wrong pressure gets a person in trouble, yielding to the right pressure can get him or her out. It is the same way with the egg. One way to get the egg out is to break it into pieces and take the pieces out one by one. That’s messy and severely damages the egg. A better way is to allow pressure opposite to the one that forced the egg into the bottle to push the egg back out.

Turn the bottle upside down so that the egg once again forms a seal against the neck of the bottle. Place your lips inside the neck of the bottle to make a seal just below the egg. Blow hard! The air lifts the egg and passes around it to enter the bottle. As the pressure inside the bottle builds, it pushes back against the egg from the inside out. When you relax and stop blowing, the unequal pressure forces the egg out of the bottle.

Supplies: Smoothly peeled hard boiled egg · Wide mouth glass bottle · Paper towels Matches · Fire extinguisher

–Character First! Education Series 2