Cycles of Time

Cycles of Time is a popular science book by the mathematical physicist Roger Penrose, published by The Bodley Head in 2010. It sets out his Conformal Cyclic Cosmology (CCC) model, an extension of general relativity that stands opposed to the widely supported multidimensional string theories and to cosmic inflation after the Big Bang.

Penrose starts from the implications of the Second Law of Thermodynamics and the inevitable drift of the universe toward a state of maximum entropy. He describes entropy as a phase space of information, in which particles, through random motion, pass over time from small regions into ever larger ones. He disagrees with Stephen Hawking about whether information is destroyed when matter falls into a black hole, since such loss would noticeably lower total entropy as black holes evaporate through Hawking radiation.

On enormous timescales, beyond 10^100 years, distance stops being meaningful because all mass dissolves into extremely red-shifted photon energy, and the universe keeps expanding without end. Penrose calls this period an aeon, and it gives way to a new low-entropy Big Bang. As preliminary evidence he cites concentric rings found in WMAP cosmic microwave background data, which he had predicted as traces of black hole collisions from the previous aeon.