January 30, 2007

Et tu, Brute?

This is straight out of my kinetic theory text book...

A man is known to breathe out about 400 cubic centimeters of air at each breath, so that a single breath of air must contain about 10^22 molecules. The whole atmosphere of the earth consists of about 10^44 molecules. Thus one molecule bears the same relation to a breath of air as a breath of air does to the whole atmosphere of the earth. If we assume that the last breath of, say Julius Caesar has by now become thoroughly scattered through the atmosphere, then the chances are that each of us inhales one molecule of it with every breath we take. A man's lungs hold about 2000 cubic centimeters of air, so that the chances are that in the lungs of each of us there are about five molecules from the last breath of Julius Caesar.

Gas dynamics can be trippy huh?

1 comment:

TinRoof said...

I've heard that before. But not in a textbook. And in reference to Jesus.

Theoretically couldn't one say we breathe a few molecules from everyone who ever lived?