Ob: I know nothing. But the way I look at it is: what is the difference between a point and infinite space? Taken from the perspective of light (travelling at the speed of light), the universe is still a single point. That is, the size of the universe is Lorenz contracted to zero. It also takes zero time to go from one end to the other ;-)
From the perspective of light, what is the difference in the universe at the instant of the big bang and some time after it? Well... potentially nothing. The structure of the universe only makes sense from within the context of the universe itself. The space of the universe only makes sense inside the universe. The time of the universe only makes sense inside the universe.
It's not the case that the big bang exploded material into empty space. The amount of energy/mass in the universe has never changed from the perspective of the universe.
The big bang is the distinction of structure in the universe. What is the difference between a point and an infinite space of uniformity? When an infinite space of uniformity loses absolute uniformity, what happens?
Why did the universe not collapse into a singularity? Because it was already a singularity. It would require some kind of structure in space in order for a "collapse" to make sense. As soon as the structure is created, it is no longer uniform, and so it will no longer collapse uniformly - especially if space is expanding at the same time. I suspect there are several black holes at the "centre" of the universe, but I can not think of a way for all the matter to collapse into a singularity.
From the perspective of light, what is the difference in the universe at the instant of the big bang and some time after it? Well... potentially nothing. The structure of the universe only makes sense from within the context of the universe itself. The space of the universe only makes sense inside the universe. The time of the universe only makes sense inside the universe.
It's not the case that the big bang exploded material into empty space. The amount of energy/mass in the universe has never changed from the perspective of the universe. The big bang is the distinction of structure in the universe. What is the difference between a point and an infinite space of uniformity? When an infinite space of uniformity loses absolute uniformity, what happens?
Why did the universe not collapse into a singularity? Because it was already a singularity. It would require some kind of structure in space in order for a "collapse" to make sense. As soon as the structure is created, it is no longer uniform, and so it will no longer collapse uniformly - especially if space is expanding at the same time. I suspect there are several black holes at the "centre" of the universe, but I can not think of a way for all the matter to collapse into a singularity.