Question: hi :) lots of of people think life began with the big bang, and think that before this only the atmosphere was around but how did the atmosphere get created? and if the big bang did occur how was it created? and what created what caused the big bang?

Philip Ratcliffe answered on 11 Nov 2014:

Gosh! Well, if that’s what they think, then we’ve got a big job on our hands straightening them out. Seriously though, you mixed up a few ideas that are either seriously out of temporal order or are not quite linked.
First of all “life” (as in animals or plants etc.) starts an awful lot later. What was before the big bang is as unknown to me as it is to anyone. However, I can categorically state that there was no atmosphere.
Hmm, well, first off there’s nothing special about atmosphere, it’s just gas, i.e. atoms and molecules of different types and again is something that again gets created some time after the big bang.
The problem is that we know where we are now and we know where we’re going and can also therefore work out where we came from. And in this way (we think) we can trace everything e see back to one single point in space and time, just as though there had indeed been a big bang. However, just like after a bomb explodes I can probably work out where (from the directions in which all the bits flew out), but I can tell you who put it there or where it came from.
There are actually still lot of tough questions to answer about what happened between the big bang and us here and now and we really ought to have those sorted out first.