The 4% Universe: Dark Matter, Dark Energy, and the Race to Discover the Rest of Reality

by Richard Panek

Dicke wondered if a theory of the universe could avoid not only a Big Bang singularity but the Steady State’s spontaneous creation of matter, and he proposed a compromise of sorts: an oscillating universe. Such a universe would bounce from expansion to contraction to expansion throughout eternity, without ever reaching absolute collapse or, between collapses, eternal diffusion. During the expansion phase of such a universe, galaxies would exhibit redshifts consistent with what astronomers were already observing. Eventually the expansion would slow down under the influence of gravity, then reverse itself. During the contraction phase, galaxies would exhibit blueshifts as they gravitated back together. Eventually the contraction would reach a state of such compression that it would explode outward again, before the laws of physics broke down. Dicke’s oscillating universe would therefore neither emerge from nor return to the dreaded singularity, though the earliest period of its current expansion would resemble a Big Bang.