The Arrow of Time
Does time run backward in other universes? It would match the symmetry of many other aspects of our physics.
The source: “Does Time Run Backward in Other Universes?” by Sean M. Carroll, in Scientific American, June 2008.
The mysteries of black holes and supernovas notwithstanding, the universe on the whole is a law-abiding place. From galaxies of stars to the tiny particles that constitute atoms, objects interact with each other according to rules that scientists think they understand. But one aspect of the...