We put an egg in a bottle: atmospheric pressure experience
This experience is extremely simple, but at the same time very informative for children and able to greatly amuse adults. Place a burning candle at the bottom of the wide-necked bottle and let stand for a while so that the air inside the bottle warms up well. Then put a peeled boiled egg on the neck of the bottle and observe.
1. To ensure that the experience is guaranteed, it is better to prepare the egg well. Try not to digest it. Hold the boiled egg in cold water: after removing the shell, the protein should be smooth to fit snugly against the neck of the bottle without letting air in. Dip the peeled egg in water. A wet (and slippery) egg is more likely to crawl into a bottle than a dry one.
2. Pick up a bottle in the store, the neck diameter of which roughly corresponds to the diameter of the egg. Suitable bottles for fermented milk products, juices, ketchup. However, one should not be too zealous: the vacuum creates sufficient force to deform the egg strongly and drag it even through a narrow neck.
3. Lowering a burning candle to the bottom of the bottle can be difficult. This is easier to do by sticking a piece of wire or a knitting needle directly into paraffin to use as a handle.
First of all, the oxygen needed for burning will end in the bottle, and the candle will go out. The air inside will begin to cool and, accordingly, decrease in volume. The pressure in the vessel will become less than atmospheric, and the egg will slowly and surely be pulled into the bottle. You will be surprised how reliable this experience is and how strongly the vacuum formed in the bottle can compress an egg.
For the most curious researchers, we offer an additional task: figure out how to get an egg from a bottle.The article “Eggs sacrificed to science” was published in the journal Popular Mechanics (No. 8, August 2013).