Phys.org March 5, 2021
The classical Gibbs paradox concerns the entropy change upon mixing two gases. Whether an observer assigns an entropy increase to the process depends on their ability to distinguish the gases. Moving the thought experiment into the quantum realm researchers in the UK have shown that the ignorant observer can extract work from mixing different gases, even if the gases cannot be directly distinguished. In the macroscopic limit, the quantum case diverges from the classical ideal gas: as much work can be extracted as if the gases were fully distinguishable. They showed that the ignorant observer assigns more microstates to the system than found by naive counting in semiclassical statistical mechanics. This demonstrates the importance of accounting for the level of knowledge of an observer, and its implications for genuinely quantum modifications to thermodynamics…read more. Open Access TECHNICAL ARTICLEÂ
Schematic of the quantum mixing process. Credit: Nature Communications volume 12, Article number: 1471 (2021)