Question about the Big Bang and its center point?

[misslabeled]

Every once in a while I start thinking about something and my brain really starts to hurt when I try to work it out. Now it happened again while pondering the Big Bang, and I was wondering what the theories were on this:

The Big Bang starts at a single point, but did it expand outward in all directions or from a single point forward, like when Mt. Saint Helens blew out the side? I was wondering because I was watching History Channel and they said we can only look back so far until they reach what they illustrated as a big green background. Does that really mean they hit the wall and that's where the BB started? Or is there more universe extended an equal distance past the point of origin?

Also, if we're looking back to where we expanded "from," what should we see if we spun the scope around in the opposite direction and effectively looked toward where we are expanding "to?" Or is there such a thing?

I can't wrap my head around the paradox--at least to me--of if the universe is always expenading, what is it expanding against? If we know we're looking toward the point of origin and can't look any farther, what are we looking at when we shift our gaze?

I guess there are actually a lot of questions in there, but mostly I was trying to visualize the BB and go from there.

 

[guanotwozero]

Ah, no, the Big bang didn't start at a central point, it happened everywhere. The universe is a continuum; it has no centre or edges. It's spacetime itself that is expanding in all directions everywhere, not from a central point. We need at least 4 dimensions to describe the expansion, so we can't say it's expanding 'into' something in a spatial sense.

We don't know what caused the Big Bang, but we do think that time itself originated with it, as part of space-time. In terms of any precursor or cause, we have no way of knowing at present, due to lack of evidence.