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by jbay808 1520 days ago
Alright. I agree we seem to be stuck in a weird loop where we agree about all the observable facts but somehow are on different wavelengths in spite of that.

And I totally agree, entropy is a property of a macrostate. The information step comes inseparably in when you go from a system description to a macrostate. And you might just shuffle the confusion from not knowing what entropy is to not knowing what a macrostate is.

If you think it's clearer to teach students by explaining that the entropy of a macrostate is an objective property of that macrostate, that's fine. Just don't leave them believing that the entropy of a brick is an objective property of that brick.

1 comments

Why shd the entropy of a brick not be an objective property (apart from a constant). I mean you can measure it, isnt it basically the integral of C/T dt?
That would be a circular calculation, because the foundational definition of temperature is rooted in entropy: T = 1/(dS/dQ).

You can measure the temperature of a brick with a thermometer, but then you should understand what that thermometer is really telling you: https://bayes.wustl.edu/etj/articles/theory.1.pdf

And when you do that, you'll see why a thermometer doesn't do a good job of measuring the effective temperature of, say, a pumped laser crystal.