= 27d567bc2d48d9f40e9ccc20ea370b15)
RichardKennaway comments on Entropy and Temperature - Less Wrong Discussion
You are viewing a comment permalink. View the original post to see all comments and the full post content.
= 783df68a0f980790206b9ea87794c5b6)
Loading…= b715d02e85f7b3b4ae65ca3d3e450868)
Subscribe to RSS Feed
Powered by Reddit
= f037147d6e6c911a85753b9abdedda8d)
You are viewing a comment permalink. View the original post to see all comments and the full post content.
Comments (96)
And will we both predict the same result when someone puts their hand in it?
Probably yes, but then I will have to say things like "Be careful about dipping your finger into that zero-Kelvin block of ice, it will scald you" X-)
It won't be ice. Ice has a regular crystal structure, and if you know the microstate you know that the water molecules aren't in that structure.
So then temperature has nothing to do with phase changes?
Temperature in the thermodynamic sense (which is the same as the information-theoretic sense if you have only ordinary macroscopic information) is the same as average energy per molecule, which has a lot to do with phase changes for the obvious reason.
In exotic cases where the information-theoretic and thermodynamic temperatures diverge, thermodynamic temperature still tells you about phase changes but information-theoretic temperature doesn't. (The thermodynamic temperature is still useful in these cases; I hope no one is claiming otherwise.)
You probably know this, but average energy per molecule is not temperature at low temperatures. Quantum kicks in and that definition fails. dS/dE never lets you down.
Whoops! Thanks for the correction.
Aha, thanks. Is information-theoretic temperature observer-specific?
In the sense I have in mind, yes.
I am somewhat amused that you linked to the same post on which we are currently commenting. Was that intentional?
Actually, no! There have been kinda-parallel discussions of entropy, information, probability, etc., here and in the Open Thread, and I hadn't been paying much attention to which one this was.
Anyway, same post or no, it's as good a place as any to point someone to for a clarification of what notion of temperature I had in mind.