What Is Entropy?

Nitpick in the article conclusion:

>Heat flows from hot to cold because the number of ways in which the system can be non-uniform in temperature is much lower than the number of ways it can be uniform in temperature ...

Should probably say "thermal energy" instead of "temperature" if we want to be really precise with our thermodynamics terms. Temperature is not a direct measure of energy, rather it is an extensive property describing the relationship between change in energy to change in entropy.

I think you used “extensive” in the sense of “defined for the whole system and not locally”. It’s true that thermodynamics is about systems at equilibrium.

I meant to say "intensive" in the physics sense but just brain farted while typing.

Ah, then I don’t see what’s wrong with “the number of ways in which the system can be non-uniform in temperature is much lower than the number of ways it can be uniform in temperature”. In equilibrium one doesn’t have a gradient of temperature because “…” indeed.