Then turn the bottle upside down so that the egg fits in the neck of the bottle. If you are lucky, the egg will drop out. If not, try warming the neck of the bottle with warm water. The egg dropped into the bottle. The burning paper burns for a while and extinguishes.
Fire needs oxygen in the air to keep burning.
As the paper burns, it uses up the oxygen in the bottle, the remaining air gets hot and expands, and some slips past the egg. The oxygen being burnt and the other gases slipping out leaves less air inside the bottle, resulting in lower air pressure. The stronger air pressure outside the bottle then pushes the egg in. Homepage Last modified on Tuesday 8th October 1996. Copyright 1996 Singapore Polytechnic Project.