Every visual simulation of big bang is misleading, as it shows the "bang" from far away perspective, like viewer is watching it from a distance. The fact is that there was no such perspective available. There was no space outside the bang to stand at and watch the explosion.

So, how do we know it's not an observable perspective?

Let's assume for the sake of argument that there was existence before the big bang.

The universe has expanded at a rate that is faster than the speed of light. Meaning, at the farthest edge of the known universe, there are objects that constantly leaving our viewable area. They are expanding away from us at a rate that that does not allow the light to reach us.

So....anything outside of that area is just unreachable to us. The most we can do is infer something about what's out there from the cosmic microwave background radiation. Which means, anything OLDER than the universe itself was lost to our observation and totally un-viewable to us.

/r/space Thread Parent