Big Bang

Bye-bye to the Big Bang

During an infinitesimal moment in time just after the Big Bang, the Universe expanded to more than a billion, billion times its original size through a process called cosmological inflation. Or did it? Huge cosmological experiments have failed to find the much-sought-after fingerprint of inflation in the cosmic background radiation, and some theorists feel that the theory has outlived its usefulness. To replace it, some propose a ‘Big Bounce’, with the Big Bang as the turning point in an ongoing cycle of contraction and expansion. Or even a mirror universe — where antimatter replaces matter and time flows backwards — that extends out in reverse from the event we call the Big Bang.

BBC Future | 17 min read