November 28, 2007


I've been reading The Quantum World: Quantum Physics for Everyone. I vaguely remember studying the subject in high school physics--the thing I remember most is that while I had all kinds of problems with classical physics (I think some of the math threw me), I really enjoyed the few weeks (was it even two?) we spent discussing quantum mechanics.

I find this passage particularly moving:

Left alone, the neutron lives, on average, a whole fifteen minutes before it vanishes in a puff of three other particles. Fortunately again for us humans, the neutron is stabilized within atomic nuclei, so certain combinations of up to 209 protons and neutrons can bundle together and live forever. This means our world is made of scores of different elements, and not just the single element hydrogen. And it's all because mass is energy and energy is mass.

We are in the realm of Lucretius.

For some time, I have been troubled by the notion of entropy: why is it we live in a highly sophisticated, structured world when the rules of classical physics suggest that we should trend toward a simpler state. (Julian Barbour raises this problem in The End of Time: The Next Revolution in Physics. Perhaps I'm just too dense to understand his argument, but it did not seem to me that he resolved the problem.) Quantum mechanics suggests that at the subatomic level, there are pathways to both simplicity and complexity, as well as discoverable reasons for the tendency towards the latter.

Posted by Ideofact at November 28, 2007 11:30 PM