Mike Strand wrote:
Clearly stated, Ginkgo, but I'm still puzzled. Take the idea that the universe itself creates more space/time. Very clearly stated. And yet somehow I'm still puzzled. For example, where does the universe get more space/time, and how does it make it? And how can there be room for it? -- we're back to Seeker36's original question, it seems. Is there an infinite emptiness into which universes pop into being?
The big bang is based largely on a mathematical theory that starts with a point in time labeled with zero corresponding to the start of the big bang and based on physics theories. It says nothing about what was happening, if anything, at times before zero. Does time stretch forever into the past and forever into the future, with the big bang event stuck somewhere "in between"?
I've heard physicists say time itself started with the big bang. Even more of a mystery! Other physicists (Julian Barbour, for example), are trying out new theories that leave out the time variable.
So much for intuition.
As to how the universe creates matter? I think ForgedinHell's answer is right. Basically, matter pops in and out of existence (well that's my understanding). I guess there is room for it because the universe keep accelerating away at an ever increasing rate. No matter where you are in the universe every point will be moving away from the point you choose to occupy. It is a bit like getting a balloon and covering it with black dots and slowly blowing it up. As you do you will see very dot is moving away from every other dot.
There was no time before the universe because if the universe didn't exist there would be no time. Time and space started at the instance of the Big Bang.
When we look into the night sky we cannot point to a particular place and say, "Yes, that is where the Big Bang occurred". It didn't actually occur anywhere, while at the same time occurring everywhere. Where ever you are in the universe you are at the centre.
While a lot of this stuff defies our common sense. However, it is likely that common sense is not as common and sensible as we thought.
We know that galaxies are moving away at an increasing rate because we can actually observe this so it is more than just a mathematical possibility.
Non-expert opinion by the way.