Preprint Clarifies Why Gravitational Collapse Increases Total Entropy Despite Reduced Volume
The preprint demonstrates that gravitational contraction increases total entropy via radiation, preserving the second law. It bridges elementary thermodynamics and black-hole physics with minimal math. Evidence is conceptual rather than empirical; a classroom trial would strengthen claims.
The paper compares an ideal gas in free expansion, where entropy rises with volume, against a self-gravitating cloud where contraction releases gravitational potential energy that is radiated away. Elementary thermodynamics shows the entropy of the surroundings increases more than any local decrease, satisfying the second law when radiation is included. This resolves the apparent paradox without invoking exotic physics.
Pinochet extends the argument to black holes by invoking the generalized second law, where horizon area plus exterior entropy never decreases. The treatment draws on Bekenstein's 1973 bound and Hawking's 1975 radiation calculation but keeps mathematics minimal, targeting university courses. It correctly flags that ordinary thermodynamic intuition fails when gravity dominates long-range correlations.
The analysis misses quantitative estimates of radiation entropy for realistic astrophysical objects and does not address recent debates on whether Hawking radiation preserves unitarity. A natural strengthening would be a short numerical example calculating entropy flux for a collapsing molecular cloud of given mass and temperature.
Future work could test whether this framing improves student performance on conceptual questions about gravitational thermodynamics in controlled classroom trials.
Pinochet: At least two introductory physics textbooks will cite this framework by 2029.
Sources (2)
- [1]Primary Source(https://arxiv.org/abs/2610.08832)
- [2]Supporting Source(https://journals.aps.org/prd/abstract/10.1103/PhysRevD.7.2333)