Entropy is Randomness. Always on my mind. My favorite notion in physics.
As I drove out there today—the slow way, south on Harlem, pausing for my customary “what if” moment as I passed 3040 S., briefly skimming the surface of a whole different branch of science—I was thinking about it.
Did the entropy of the water increase or decrease when it froze? Surely, the pipe’s entropy increased when it burst. Water, transitioning to ice, is losing entropy, losing randomness. It lost it to the atmosphere, whose temperature was so much lower last week. Especially beneath the empty house, with the thermostat (ha! “thermo” “stat”) down some to save a few bucks while waiting for the sale to close. But wait, can entropy move to something with a lower temperature? Does entropy move? Or is that heat? What about the second law? Damn it, I was bad at thermo, and screw you, Northwestern, for having that indecipherable Russian TA teach such an important class. Maybe entropy and temperature are only comparable between like objects? I dunno. The pipe burst, and now there’s randomness, all right.
Entropy all over the fucking place. All the entropy we’ll ever need.