Landau and Lifshitz vol 5 <https://en.wikipedia.org/wiki/Course_of_Theoretical_Physics#...> is the standard textbook. There's an older copy on the Internet Archive <https://archive.org/details/landau-and-lifshitz-physics-text...>. (Having the background of L&L vol 9 makes a classroom demonstration even easier: a small handful of electronic parts for a resistive-capactive low-voltage DC electric dipole, a decent oscilloscope or other apparatus to measure and record fluctuating voltage, and a thermometer).
The probability of an out-of-equilibrium structure spontaneously fluctuating (briefly!) into existence depends on the complexity of the structure, and Boltzmann brains are much much much less complex than the whole Earth, solar system, Milky Way, or the early universe in which these structures' precursors originated. So therefore any theory compatible with statistical physics in which the early low-entropy state of the universe is a fluctuation in a higher-entropy "gas" is imperiled.
For the philosopher or two who wrote comments above in this thread, https://plato.stanford.edu/entries/statphys-Boltzmann/ is probably of interest.
I have studied and reflected on the subject and I really think Boltzman brains and Schröedinger cat are thought experiments that go way over the head of their pop sci/undergrad classroom interpretations.
Schrödinger or Schroedinger: it is just you on HN <<https://duckduckgo.com/?q=%22Schr%C3%B6edinger%22+site%3Anew...> who has used "öe", multiple times.
Boltzmann brains have nothing to do with Schrödinger: statistical mechanics works fully classically, and nobody treats Boltzmann brains in a quantum mechanical way because a Boltzmann brain is an unembodied ephemeral human brain. Natural human brains have a history of being warm and electrically noisy (any quantum features decohere faster than thought), while fluctuated-out-of-equilibrium human brains aren't around long enough to have their temperature measured, nor to produce much electrical noise.
A quantum-mechanical Boltzmann brain emerging from a gas of photons in (cold) equilibrium in which fluctuations take photons out of equilibrium and into the farrrr UV is going to be on the short-lived end of Boltzmann brains: things like annihilations and complicated decay chains will dissolve them away quickly. Which is the point. Boltzmann brains, unlike the bowl of petunias in The Hitchhiker's Guide to the Galaxy, should not have time to compose poetry.
Very hot thermal radiation is what destroys classical Boltzmann brains. They sort-of are a cool spot in an extremely violently hot bubble in an otherwise cold (colder than brains!) gas of almost everywhere uniform temperature.
> Yes I am familiar with the physics ...
> Quoting a university [physics] textbook on a philosophical argument
... which is philosophizing about actual physics ...
> is an interesting choice.
Well, what textbooks or other sources do you rely upon when philosophizing about fluctuation theory? What have you read or taught from?
> pop sci/undergrad classroom interpretations
?
