Can we say that thermal entropy is more like a theoretical or statistical concept and not easy to measure?
Grok:
Yes, thermal entropy is largely a theoretical and statistical concept, rooted in the probabilistic behavior of particles in a system, as described by statistical mechanics. It quantifies disorder or the number of possible microstates, which isn't directly measurable like temperature or pressure. Measuring entropy typically involves indirect methods, such as calculating changes based on heat transfer and temperature (e.g., ΔS = q/T for reversible processes), but these rely on idealized assumptions and precise conditions, making direct measurement challenging in practice.