What Happened Before the Big Bang?

PBS Member Stations rely on viewers like you. To support your local station, go to: http://to.pbs.org/DonateSPACE ↓ More info below ↓ Check out the new Space Time Merch Store! https://pbsspacetime.com/ Support Space Time on Patreon https://www.patreon.com/pbsspacetime We actually have a pretty good idea of what might have happened before the Big Bang. That is, as long as we define the Big Bang as the extremely hot, dense, rapidly expanding universe that is described by Einstein’s equations. That picture of the universe is very solid down to about a trillionth of a second...