Circular patterns within the cosmic microwave background suggest that space and time did not come into being at the Big Bang but that our universe in fact continually cycles through a series of "aeons". That is the sensational claim being made by University of Oxford theoretical physicist Roger Penrose, who says that data collected by NASA's WMAP satellite support his idea of "conformal cyclic cosmology". This claim is bound to prove controversial, however, because it opposes the widely accepted inflationary model of cosmology.