Editing Philosophy of physics (section)

==Philosophy of thermal and statistical physics==
The philosophy of [[Thermal physics|thermal]] and [[Statistical mechanics|statistical physics]] is concerned with the foundational issues and conceptual implications of [[thermodynamics]] and [[statistical mechanics]]. These branches of physics deal with the macroscopic behavior of systems comprising a large number of microscopic entities, such as particles, and the nature of laws that emerge from these systems like [[Irreversible process|irreversibility]] and [[entropy]]. Interest of philosophers in [[statistical mechanics]] first arose from the observation of an apparent conflict between the [[T-symmetry|time-reversal symmetry]] of fundamental physical laws and the [[Irreversible process|irreversibility]] observed in thermodynamic processes, known as the [[arrow of time]] problem. Philosophers have sought to understand how the asymmetric behavior of macroscopic systems, such as the tendency of heat to flow from hot to cold bodies, can be reconciled with the time-symmetric laws governing the motion of individual particles.

Another key issue is the [[Probability interpretations|interpretation of probability]] in [[statistical mechanics]], which is primarily concerned with the question of whether probabilities in statistical mechanics are [[Epistemology|epistemic]], reflecting our lack of knowledge about the precise microstate of a system, or [[Ontology|ontic]], representing an objective feature of the physical world. The epistemic interpretation, also known as the subjective or [[Bayesian]] view, holds that [[Probability|probabilities]] in [[statistical mechanics]] are a measure of our ignorance about the exact state of a system. According to this view, we resort to probabilistic descriptions only due to the practical impossibility of knowing the precise properties of all its micro-constituents, like the positions and momenta of particles. As such, the [[probabilities]] are not objective features of the world but rather arise from our ignorance. In contrast, the [[Ontology|ontic]] interpretation, also called the objective or [[Frequentist probability|frequentist]] view, asserts that probabilities in statistical mechanics are real, physical properties of the system itself. Proponents of this view argue that the probabilistic nature of statistical mechanics is not merely a reflection of our ignorance but an intrinsic feature of the physical world, and that even if we had complete knowledge of the microstate of a system, the macroscopic behavior would still be best described by probabilistic laws.