  The theoretical maximum time variation in the electronic charge permitted by
the Generalized Second Law of Thermodynamics applied to black holes radiating
and accreting in the cosmic microwave background matches the measured
cosmological variation in the fine structure constant claimed by Webb et al..
Such black holes cannot respond adiabatically to a varying fine structure
constant.

General Relativity and Quantum Cosmology;Cosmology and Nongalactic Astrophysics;High Energy Physics - Theory