Comment by sat_solver

Comment by sat_solver a day ago

3 replies

You're thinking of information entropy, which is not the same concept as entropy in physics. An ice cube in a warm room can be described using a minimum description length as "ice cube in a warm room" (or a crystal structure inside a fluid space), but if you wait until the heat death of the universe, you just have "a warm room" (a smooth fluid space), which will have an even shorter mdl. Von Neuman should never have repurposed the term entropy from physics. Entropy confuses a lot of people, including me.

hackinthebochs a day ago

Maxwell's demon thought experiment implies they are the same concept. Given a complete knowledge of every particle of gas you can in principle create unphysical low entropy distributions of the particles. This[1] goes into more detail.

[1] https://en.wikipedia.org/wiki/Entropy_in_thermodynamics_and_...

nick__m a day ago

And somewhat surprisingly the heat death of the universe is the maximal entropy state.

Because there are an infinite number of microstates (all the particles are interchangeable) that lead to the same macrostate: nothing happening for ever!