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That misguided attempt has resulted in full graduate courses and textbooks. Maybe one look is not all that it takes to fully assess its worthiness. https://www

by kgwgk 2y ago

That misguided attempt has resulted in full graduate courses and textbooks. Maybe one look is not all that it takes to fully assess its worthiness. https://www.amazon.com/Microphysics-Macrophysics-Applications-Statistical-Mathematical/dp/3540454691 https://www.amazon.com/Microphysics-Macrophysics-Application... https://arxiv.org/pdf/cond-mat/0501322 https://arxiv.org/pdf/cond-mat/0501322

kergonath 2y ago
Plenty of bad stuff made its way into textbooks, I saw some really dodgy stuff at uni. And for every uncontroversial statement we can find a textbook that argues that it is wrong. Sorting the good from the bad is the main point of studying science and it is not easy. What is also important is that approaches that can work in some field or context might be misleading or lead to wrong outcomes in others. Information theory is obviously successful and there is nothing fundamentally wrong with it. Where we should be careful is when we want to apply some reasoning verbatim to a different problem. Sometimes it works, and sometimes it does not. Entropy is a particularly good example. It is abstract enough to be mysterious for a vast majority of the population, hence why these terribly misleading vulgarisation articles pop up so often. Thinking of it in terms of information is sometimes useful, but going from information to knowledge is a leap, and then circling back to Physics is a bit adventurous.
- kgwgk 2y ago
  Plenty of bad stuff makes its way into hackernews comments as well. Saying that “it could be wrong” doesn’t really support the “it’s wrong” claim, does it?
  - kergonath 2y ago
    I did not make that point, though. I rejected an appeal to authority because something was in a textbook. I made no comment about the validity of that person’s work in his field, I just pointed out that this transferability was limited.
    - kgwgk 2y ago
      My bad, I thought you considered Balian’s work another misguided attempt to apply information theory concepts to thermodynamics. For the record, this is the abstract of the “Information in statistical physics” article: “We review with a tutorial scope the information theory foundations of quantum statistical physics. Only a small proportion of the variables that characterize a system at the microscopic scale can be controlled, for both practical and theoretical reasons, and a probabilistic description involving the observers is required. The criterion of maximum von Neumann entropy is then used for making reasonable inferences. It means that no spurious information is introduced besides the known data. Its outcomes can be given a direct justification based on the principle of indifference of Laplace. We introduce the concept of relevant entropy associated with some set of relevant variables; it characterizes the information that is missing at the microscopic level when only these variables are known. For equilibrium problems, the relevant variables are the conserved ones, and the Second Law is recovered as a second step of the inference process. For non-equilibrium problems, the increase of the relevant entropy expresses an irretrievable loss of information from the relevant variables towards the irrelevant ones. Two examples illustrate the flexibility of the choice of relevant variables and the multiplicity of the associated entropies: the thermodynamic entropy (satisfying the Clausius–Duhem inequality) and the Boltzmann entropy (satisfying the H-theorem). The identification of entropy with missing information is also supported by the paradox of Maxwell’s demon. Spin-echo experiments show that irreversibility itself is not an absolute concept: use of hidden information may overcome the arrow of time.”

by kgwgk 2y ago

kergonath 2y ago

Plenty of bad stuff made its way into textbooks, I saw some really dodgy stuff at uni. And for every uncontroversial statement we can find a textbook that argues that it is wrong. Sorting the good from the bad is the main point of studying science and it is not easy. What is also important is that approaches that can work in some field or context might be misleading or lead to wrong outcomes in others. Information theory is obviously successful and there is nothing fundamentally wrong with it. Where we should be careful is when we want to apply some reasoning verbatim to a different problem. Sometimes it works, and sometimes it does not. Entropy is a particularly good example. It is abstract enough to be mysterious for a vast majority of the population, hence why these terribly misleading vulgarisation articles pop up so often. Thinking of it in terms of information is sometimes useful, but going from information to knowledge is a leap, and then circling back to Physics is a bit adventurous.

kgwgk 2y ago
Plenty of bad stuff makes its way into hackernews comments as well. Saying that “it could be wrong” doesn’t really support the “it’s wrong” claim, does it?
- kergonath 2y ago
  I did not make that point, though. I rejected an appeal to authority because something was in a textbook. I made no comment about the validity of that person’s work in his field, I just pointed out that this transferability was limited.
  - kgwgk 2y ago
    My bad, I thought you considered Balian’s work another misguided attempt to apply information theory concepts to thermodynamics. For the record, this is the abstract of the “Information in statistical physics” article: “We review with a tutorial scope the information theory foundations of quantum statistical physics. Only a small proportion of the variables that characterize a system at the microscopic scale can be controlled, for both practical and theoretical reasons, and a probabilistic description involving the observers is required. The criterion of maximum von Neumann entropy is then used for making reasonable inferences. It means that no spurious information is introduced besides the known data. Its outcomes can be given a direct justification based on the principle of indifference of Laplace. We introduce the concept of relevant entropy associated with some set of relevant variables; it characterizes the information that is missing at the microscopic level when only these variables are known. For equilibrium problems, the relevant variables are the conserved ones, and the Second Law is recovered as a second step of the inference process. For non-equilibrium problems, the increase of the relevant entropy expresses an irretrievable loss of information from the relevant variables towards the irrelevant ones. Two examples illustrate the flexibility of the choice of relevant variables and the multiplicity of the associated entropies: the thermodynamic entropy (satisfying the Clausius–Duhem inequality) and the Boltzmann entropy (satisfying the H-theorem). The identification of entropy with missing information is also supported by the paradox of Maxwell’s demon. Spin-echo experiments show that irreversibility itself is not an absolute concept: use of hidden information may overcome the arrow of time.”