As much as I love Nelson's book I prefer to approach teaching thermodynamics and particularly entropy without introducing microscopic notions such as ensembles, probability etc.
The first ten of these slides I use in PHYS2020 to give a succinct view of the key concepts in thermodynamics. Here entropy is a macroscopic concept associated with irreversibility.
Subscribe to:
Post Comments (Atom)
Having said that, Ross, I still think that there are some things in thermodynamics that we need to look at in terms or probabily and ensembles in the context of Nelson's book. I think that way of looking at thermodynamics makes it a bit easier to look at some of the points he's trying to get across, particularly when we're thinking about things like diffusion.
ReplyDeleteFor a lot of biology, it is fair to think of thermodynamics in the ways that we are used to.
ReplyDeleteThis is particularly true of the examples which we use to explain it, and maybe this is not coincidental - we explain what we understand, and sweep what we don't under the rug.
However, the really interesting things that happen in biology are arise because biological phenomena are not equilibrium phenomena. Therefore, although it may be useful in some regimes, we know from the very start that a formulation in terms of state functions will eventually fail us.
It is sometimes said that the information theory formulation of statistical mechanics has the advantage of being able to deal with non-equilibrium phenomena. Perhaps this is true in some respects - although ultimately the devil is always in the details. At present, I don't know enough about it to comment further.
According to chapter 6 (p223), the principle of minimum free energy at equilibrium in the system directs the attention away from the reservoir, and onto the system of interest. I've never thought about equilibrium thermodynamics in this way before.
ReplyDelete