r6 and I discuss his theory that entropy is subjective

[gustavolacerda]

r6 and I discuss his theory that entropy is subjective

I've never been satisfied with the solutions I've seen to Maxwell's Demon.
I take r6's interpretation of entropy as an agent-dependent quantity related to his knowledge, and a measurement of what one can do with this knowledge: knowledge is power. According to his theory, an all-knowing being (

Comments

[spoonless]

Some physicists used to toy with the notion that entropy is subjective and only refers to our "lack of knowledge" about a system. But from what I understand, computer simulations put and end to that way of thinking. Once it became possible to simulate a large number of interacting objects bouncing around exchanging energy, it became obvious that the entropy of a system is an objective quantity which refers to how many accessible states there are in the system

Accessible States

[r6]

Oh, it’s the number of accessible states. For god’s sake, why didn’t books and web pages say that. I had the impression that it was the number of possible states.

[gustavolacerda]

Thanks for the comment.

I briefly looked over the thread, and I noticed you asked "is entropy defined for a macroscopic particle". I think I know what you're asking here, but I'm not sure so correct me if I misinterpretted. I think what you're asking is: does entropy apply to classical systems which have no constituants small enough for quantum mechanics to play a role? And the answer is yes. Entropy is an entirely classical concept;What I meant was "macroscopic" in the sense ping-pong balls: if we had a huge box in space (zero-gravity vacuum), with billions of ping-pong balls bouncing around in it, could we define entropy based on these observable states

[darius]

ping-pong balls: Yes, though in practice the entropy from microscopic variation would be much greater still.

level of detail: See http://en.wikipedia.org/wiki/Entropy#Counting_of_microstates