Saturday, October 01, 2011

Arrow of Time/Time Reversal

Early this morning, sometime between the hours of 3 and 4 am, I woke up worrying. In that quiet, with the dog snoring softly in the curve at the back of my knees, and my husband's cpap machine inhaling and exhaling on the other side of the bed, I worried and worried and couldn't make my poor old brain let go of it: Newton's Second law of thermodynamics, entropy, and the Arrow of Time. What these say, as I understand it, is that all warm things will grow cold, that over time things break down, fall apart, and ultimately disappear entirely. As in the universe and everything in it.

Now, what I was worrying about was this: there is a law of Conservation of energy which says that the total amount of energy in a system remains constant over time, and that energy can neither be created or destroyed, but only changed from one state to another. Even in the process of Annihilation particles are not actually annihilated, but are changed into new particles.

Then there is the thing called Time Reversal, T-symmetry, T-asymmetry. How do all these things manage to work together? Do they? Sounds like they are at odds to me. I'm just saying.

Can somebody help me out here, so I won't have to spend another sleepless night?

No comments: