For simplicity, lets just imagine that our big bang is the only big bang, ever. People always ask me, when did the universe "explode" in the big bang? How long did it take, and what was before it? I always get caught in my own words when they ask, as I have never really pondered these questions. After thinking about this for a second, I tell them "It didn't take time. It happened all at once, since before the big bang, there was no time." I've never heard of this, or read anything about it, but am just assuming that this is true (just a little theory i came up with in my head?) I'm just asking if this is true. Thanks!