'What was there before the Big Bang?' That's a question that both kids and adults love to pose to anyone who seems sympathetic. After all, if the universe has only been around for roughly 14 billion years, isn't it legitimate to ask what was in existence before the mother-of-all-events cranked up the cosmos?

'Eternal inflation,' as it's called - the endless generation of new universes - may be a hyper-cosmic imperative. It seems that it must happen.

If gravity were somewhat stronger or weaker, stars wouldn't exist, and neither would you. And the same can be said of other constants of physics. Several have to be 'just right.'

Seth Shostak Quotes