The hard-boiled egg trick is a fun trick that sounds even more impressive before you see it than after.
That’s because you use a peeled egg. If you want to add a little more scientific mystery, you can combine this with the rubberized-chicken-bone stunt.
It turns out that if you soak a hard-boiled egg in vinegar for several days, the shell is eaten away, leaving the egg wrapped only in that rubbery membrane that lines the shell.
Begin with a bottle that has a mouth just a little smaller than the egg (for example, an old-fashioned milk bottle, or a big ketchup bottle). If it’s too big, the egg will fall through before you begin; if too small, the trick won’t work.
Boil some water. Now get ready to work fast. Pour the very hot water into the bottle using an oven mitt. Swish the water around until the bottle is quite hot, and then dump it down the sink. Quickly balance the egg in the opening of the bottle and wait for a few seconds. Drum roll, please, as you watch, the egg will be sucked into the bottle.
So how does it work? The boiling water heats up the air inside the bottle, making it expand. When the bottle begins to cool, the air contracts. Since the air pressure outside is now higher than the air pressure inside, it pushes the egg into the bottle.
Okay, so now you have an egg inside a bottle. Now’s the time to challenge your audience with the question: How do you get the egg out without breaking it?
It’s possible that reversing the process will workswishing ice water around inside the bottle and dumping it out before turning the bottle upside down should theoretically work.
However, there’s an easier way. Turn the bottle upside down and blow into it. The egg will move out of the way and allow air in. The increased air pressure inside the bottle should then cause the egg to pop out.