Physics
Thermodynamic reversibility
Reversibility in thermodynamics is the idealised limit in which entropy is conserved — the benchmark against which every real, entropy-producing process is measured. These references trace the concept from reversible processes and the second law to the fluctuation theorems that govern small systems.
Reversible process (thermodynamics) →
The quasi-static, entropy-conserving idealisation that can be run backwards through the same equilibrium states.
Wikipedia · concept
Second law of thermodynamics →
The entropy of an isolated system never decreases, setting the direction of spontaneous change.
Wikipedia · concept
Carnot cycle →
The reversible benchmark for heat engines, defining the maximum possible efficiency between two reservoirs.
Wikipedia · concept
Microscopic reversibility / T-symmetry →
The time-reversal symmetry of the microscopic laws of motion, against which macroscopic irreversibility stands out.
Wikipedia · concept
Loschmidt's paradox →
How can reversible microscopic laws give rise to irreversible macroscopic behaviour? The statistical resolution.
Wikipedia · concept
Nonequilibrium Equality for Free Energy Differences →
The Jarzynski equality, relating non-equilibrium work to equilibrium free-energy differences.
C. Jarzynski · Phys. Rev. Lett. 78 · 1997
Entropy Production Fluctuation Theorem… →
The Crooks fluctuation theorem, relating the probabilities of forward and time-reversed trajectories.
G. E. Crooks · Phys. Rev. E 60 · 1999
Fluctuation theorem →
Quantifies the probability of entropy-decreasing fluctuations in small systems over short times.
Wikipedia · concept