ratiocinator
Lightly seared on the reality grill.
Just to add here, general relativity itself provides a third answer, namely that the four-dimensional space-time manifold 'just is'. The manifold cannot itself be subject to time because time is a direction through it and not even one, unique direction either, all time-like directions will be seen as time from some frame of reference. It cannot, if this is the correct view, have 'come into being', there is no version of time, no time dimension along which this could have happened.You're only looking at part of the problem. The alternative is equally counterintuitive - that time and existence had a beginning. As I see it, whatever the original substance of reality was, it either never began to exist or came into being uncaused from nothing. Unless you can think of another possibility...
This sort of graphic appears in many articles about the BB:
This is a picture of a three directional object. There are, necessarily, a lot of simplifications that have gone into turning the mathematical model of four-dimensional space-time (which is non-Euclidean) into a three-dimensional object in Euclidean space, so there is much about it that shouldn't be taken seriously, but often is. However, there is one thing about it that very often isn't taken seriously but really should be. That is that it is an object. You can imagine being handed the three dimensional model and holding it in your hands. Now if you were to wonder how the model was made, would you be concentrating in the bit labelled 'Big Bang' at one end?
I would suggest, that you obviously wouldn't be. And that's what people should take seriously.
If general relativity is broadly right (and we can't be sure until we have unified it with quantum field theory), then, any talk of it "coming into existence" at the BB is nonsensical. If there is a reason for its existence at all, then you'd be looking at the problem in entirely the wrong way.
This is actually the case regardless of whether the BB means that the universe is finite in the past directions through it or not. Also worth noting that some hypotheses suggest that we can extent time 'back' through the BB but that it reverses its direction. Both directions away from the BB would be pointing in future directions.
Even if all this is wrong, it is logically self-consistent, and so cannot be dismissed as a possibility.
Last edited: