Before the Big Bang

Our Big Bang may have been just one of countless similar events

Everything in our universe originated after the Big Bang, so there are no conceivable observations we can make that would tell us anything about what happened before then.

For some scientists this makes the question of what happened before the Big Bang meaningless, but for others it’s no obstacle to theoretical speculation.

One of the most intriguing suggestions is the concept of eternal inflation. The current

Big Bang theory requires the universe to go through an initial period of very rapid inflation, which then transitioned abruptly to the more sedate expansion we see today. But what if when our own universe dropped out of this inflationary phase it was just a tiny bubble in a vast sea of inflating space? This is the idea behind eternal inflation, which would see a whole host of other bubble universes popping up at different times in other parts of the inflationary sea.