Is information a physical quantity? Or perhaps it is merely a result of our logical deduction. These two don’t conflict with each other in a Bayesian framework, as two probabilities always exist: one from the statistical sample to be measurement, and one from the conclusion we draw from these measurements. I will discuss the information and measurement aspects of statistical mechanics: what happens after the moment that we stick a thermometer into a box. This sounds classical, but the quantum case is not much different. Discussions are based on the pioneering work by E. T. Jaynes [1], and recent realizations and extensions to the same principle [2]. No prior knowledge is required. 

 

[1] E. T. Jaynes, Phys. Rev. 106, 620 (1957).

[2] M. N. Bera, A. Riera, M. Lewenstein, A. Winter. Arxiv 1707.01750 (2017).