What Came Before the Big Bang?

Cosmologist Alexander Vilenkin believes the Big Bang wasn't a one-off event, but merely one of a series of big bangs creating an endless number of bubble universes.


It is cosmology’s most fundamental question: How did the universe begin?

The question presupposes that the universe had an actual starting point, but one might just as well assume the universe always was and always will be. In that case, there would be no beginning whatsoever — just an ever-evolving story of which we’re catching a mere glimpse.

“We have very good evidence that there was a Big Bang, so the universe as we know it almost certainly started some 14 billion years ago. But was that the absolute beginning, or was there something before it?” asks Alexander Vilenkin, a cosmologist at Tufts University near Boston. It seems like the kind of question that can never be truly answered because every time someone proposes a solution, someone else can keep asking the annoying question: What happened before that

But now Vilenkin says he has convincing evidence in hand: The universe had a distinct beginning — though he can’t pinpoint the time. After 35 years of looking backward, he says, he’s found that before our universe there was nothing, nothing at all, not even time itself.