Don’t forget the best bit – after the egg falls in. What you’re supposed to do is put your lips to the bottle top, and blow air in as hard as you can, pressurizing it. Hold the bottle upside down so the egg seals the inside. Then take your lips and the resulting air pressure away. The egg will start to be forced back out.
This was in my children’s book of science way back in the '70’s. It was part of a discussion on how air is a “real” thing, how it is matter – it takes up space, has weight, and it’s pressure can do work. Things I’m guessing kids of the 1970’s didn’t know, or something.
Just as a point of interest, has anyone tried holding the egg firmly in place during and for a while after the burning is going on, in an attempt to prevent any heated air from escaping? (Putting a little liquid soap around the joint would indicate success in preventing escape). If that were successful then whether egg did or did not pop into the jar later would pretty much verify or rule out the idea of the combusted materials taking up less space.
Or, another approach might be to stretch a balloon or piece of plastic wrap across the opening of the bottle. Then see, does it bulge inwards afterwards?
Thinking more about it, it seems quite difficult to prevent some hot air from escaping in the time between inserting the match and placing the egg (or whatever). Perhaps there is some way to use a timer or a remote control.
I really think this needs a large, wasteful, government-funded study.
