A Brief Explanation of the Big Bang

Or: How Everything Came from Pretty Much Nothing

I'm writing this with a bit of an agenda.

I spend a lot of time on Yahoo! Answers, specifically in the Religion and Spirituality section. It's a lively place, full of heated arguments. At least once a day, someone asks something about the Big Bang, typically what caused it if there was nothing before it. This is generally a tactic used to suggest a god exists who kicked the whole process into motion, though it usually sidesteps the question of where that god came from.

These questions get a lot of answers, but they generally tend to be of the 'I don't know' category, or to be generous, are a little misinformed when it comes to modern theory.

I answer, but I'm getting very tired of typing it out every single time with minor variations. If I've done this once, I've done it at least fifty times. Hence, with a certain sense of hubris, I decided to try and sum up the relevant theories in a brief article I could just link to.

So.

Firstly, a lot of people ask what was before the Big Bang. That's a relatively easy one to answer; nothing. No matter, no energy, nothing but nothing. Not even a vacuum. There wasn't even any space for something to occupy, no time for it to exist in. There wasn't a before, before.

So what led from this nothing to, well, everything? The original Big Bang suggested that everything, every single piece of matter that now exists, was originally scrunched up into a point so small it stops having any dimensions at all, a singularity. In cases like this, some suggested all that matter came from a previous, collapsed universe.

Nowadays, scientists use terms like 'a quantum fluctuation resulting in a particle of negative pressure vacuum energy'. Which to me sounds like something from Star Trek, but apparently it's perfectly acceptable to allow the universe to spontaneously generate in this way, and it's backed up by empirical tests. Either way, you now have your singularity; either a zero-event point containing everything, or one containing nothing. Your mileage may vary, but not by as much as you'd imagine.