I’m not really any sort of expert on relativity, but occasionally I play one on the internet. Any actual experts are encouraged to point out mistakes made below:
According to Einstein, space and time are really one and distorting space can also distort time. It is for that reason that a vessel could travel “faster than light” in a certain sense by expanding the space on one side of it and compressing it on the other side (although it is believed this would require more energy than exists in the universe). As you wind back time near the big bang space becomes so compressed that normal laws of physics cease to apply. At the very beginning there was no space and hence no time. It is thus meaningless to ask about the time before the Big Bang.
That is something I have often heard from scientists, so I am more confident in its accuracy. The next one gets into weird territory:
It is not merely the case that everything is pre-determined. According to Einstein we only subjectively perceive time to be moving forward from an absolute past to present to future, but in fact no two events can actually be objectively “simultaneous”, and when two different observers disagree over which of two events happened first there is not necessarily a correct answer. Space and time are one and every event is not simply destined to happen but in a sense HAS ALREADY HAPPENED.
I’ve heard fewer people push that line, so I could well be misrepresenting things, and quantum mechanics might also clash with the super-determinism I describe.