AS A COSMOLOGIST, ONE OF THE MOST OFT-REPEATED questions I hear is “What came before the Big Bang?” The late Stephen Hawking considered this inquiry as metaphysically nonsensical as asking “What’s north of the North Pole?”1 To Hawking, and many like-minded cosmologists, time began with the Big Bang. Asking what happened before was a fool’s errand—tantamount to asking what time was before time began—for the beginning of time is forever firewalled off from our knowledge. Yet, decades later, modern cosmologists cannot resist exploring models which neatly incorporate any date in the past, even one predating the beginning of our current universe. It seems Hawking’s dismissal of any history predating the Big Bang was unwarranted.
Figure 1. Brief history of the universe, from the Big Bang to today.