RE: Does random have rules?
March 27, 2015 at 9:29 am
(This post was last modified: March 27, 2015 at 9:32 am by watchamadoodle.)
(March 27, 2015 at 9:06 am)Alex K Wrote: the second law definitely holds only on average for large enough systems, and for finite systems there is a small chance that they are violated. It's just that for macroscopic systems this probability is unmeasurable small.(I'm probably going to get the details all wrong, but hopefully you can decipher the essence.)
Typical example: if you have a box full of gas molecules, there is the slim chance 2^-N that at some point in time they will all sit in the left half of the box, which would correspond to a state of much lower entropy than the starting state.
It seems like the slim chance of all the gas molecules being in the left half of the box would require a simultaneous observation of all those particles? Maybe some of the thermodynamic laws can be restated to say that such an observation is illegal?
If the whole universe was just two particles in their probability wave state, then it seems like the entropy of the universe might be the sum of the variances of the two probability waves? If the two probability waves have a single narrow peak, then the entropy would be lower than if the probability waves were more diffuse?
At some point the particles collide or observe each other and their probability waves collapse? Then there are two new probability waves with new entropy values?
Does thermodynamics work with such a simple system?
