Egg in a bottle

Friday, October 16th, 2009
More eggs! We are having so much fun with eggs these days. Teacher had 2 bottles with small necks. We were wondering if there is any way we could get a boiled egg into the bottle, even though the egg was bigger than the neck of the bottle.Teacher had to do these investigations herself because the water in the bottles was boiling hot - too dangerous for us to touch. First she tried to push a boiled egg, with the shell on it, into the bottle. It didn't fit. Next she peeled the egg and tried again. With water in the bottle, the egg just sat happily on top. The action started when teacher poured the boiling water out of the bottle, and then put the egg on top. Once the bottle started cooling down, the egg began to be sucked into the bottle. It got sucked in a little, but we think the eggs we tried were just too big - the rim of the bottle cut the egg so the egg broke (but half of it ended up in the bottle). We tried again with another egg. This time teacher lit a candle and put the egg on top. The candle went out (because there was no more oxygen in the bottle). When the bottle cooled, the egg was sucked into the bottle. Again the egg got stuck in the neck of the bottle. The seal was so good that we could turn the bottle upside down, and the egg stayed put.
We loved this investigation. We can't wait to try it again with smaller eggs. Are you wondering why it works? It works because when the bottle is emptied of boiling water, or when it has a match that had been lit inside it, the bottle is full of steam. Steam takes up lots of space. When the bottle cools down the steam inside turns into water. Water doesn't take up as much space as steam, so inside the bottle there is a vacuum and the egg is sucked (under pressure) into the bottle.