The Many Worlds Interpretation of Quantum Mechanics. See the FAQ for more details. In some games between two or more players the optimal strategy is a random mixture between some moves, with as little pattern as possible. Timelike A curve through spacetime whose velocity at no point becomes greater than the speed of light.
Matter moves along timelike curves.
The Eternal Return is Tipler's term for a state where a system repeats its states endlessly, without ever changing. The only way to avoid it is to expand the phase space. If spacetime isn't isotropic, then the anisotropy can at least theoretically be used as an energy source. Since the anisotropy of spacetime increases, it will be dominant in certain forms of collapses of closed universes, which is what Tipler counts on in his scenario. Currently the cosmic background radiation is isotropic, but in some cosmological models the universe will expand or contract in an anisotropic way.