Cycles of Time
Roger Penrose
 Penrose examines implications of the Second Law of Thermodynamics and its inevitable march toward a maximum entropy state of the universe. Illustrating entropy in terms of information state phase space (with 1 dimension for every degree of freedom) where particles end up moving through ever larger grains of this phase space from smaller grains over time due to random motion. He disagrees with Stephen Hawking's back-track over whether information is destroyed when matter enters black holes. Such information loss would non-trivially lower total entropy in the universe as the black holes wither away due to Hawking radiation, resulting in a loss in phase space degrees of freedom. Penrose goes on further to state that over enormous scales of time (beyond 10100 years), distance ceases to be meaningful as all mass breaks down into extremely red-shifted photon energy, whereupon time has no influence, and the universe continues to expand without event \rightarrow \infty. This period from Big Bang to infinite expansion Penrose defines as an aeon. The smooth “hairless” infinite oblivion of the previous aeon becomes the low-entropy Big Bang state of the next aeon cycle. Conformal geometry preserves the angles but not the distances of the previous aeon, allowing the new aeon universe to appear quite small at its inception as its phase space starts anew. Penrose cites concentric rings found in the WMAP cosmic microwave background survey as preliminary evidence for his model, as he predicted black hole collisions from the previous aeon would leave such structures due to ripples of gravitational waves.