Want a scientific excuse to waste an egg? Sena and I found this experiment that uses vinegar to make a bouncy egg yesterday.
We put a whole raw egg into a bowl full of vinegar and let it sit for 24 hours. Initially, a couple of hours after we put the egg in the bowl of vinegar, Sena noticed pressure building up in the bowl. Even though the lid was on, vinegar was starting to leak out so she set it inside a larger bowl.
I started to worry a little about whether enough pressure would build to blow the lid off in an explosion—but it never happened.
I think a lot of people get this idea around Easter. The main thing that happens is the vinegar (a weak acid) eats away at the egg shell (which is made of calcium carbonate) until the shell dissolves. Carbon dioxide gas bubbles form. It leaves a rubbery membrane behind. The water in the vinegar diffuses across the membrane.
The egg had a lot of bubbles all over it and was visibly larger. The shell had completely dissolved—and it bounced! Sena tried bouncing it from higher and higher levels until the inevitable splat. All that was left was the yolk and the membrane.
It kind of reminds me of the morgue autopsy scene in the 1997 Men in Black movie between the deputy medical examiner Dr. Laurel Weaver and Agent J (everything reminds of Men in Black movies):
Dr. Weaver: Feel that? Where the eggshell should be? Notice anything strange?
Agent J: No, all fine.
Dr. Weaver: Doctor, the whole shell is missing.
Agent J: Well, of course. That’s obviously the first thing I noticed. What I was pointing out is the fact that there are no… pieces…of it left. You know, so the shell is intact; wherever it is whole, somewhere. That we can be sure of.
Go Retire Psychiatrist 