My apologies if there are some related discussions on this topic in another thread here, but I could not find one specifically addressing this question. Big bang theory, as it currently stands, talks of some extraordinarily precise time measurements; you see numbers like that 10^-37 sec after the Big Bang, cosmic inflation happened. But the question is, this is according to what frame of reference? Time has meaning only when there is propagation of electromagnetic waves. It really has no meaning in a black hole, or, I presume, at the time of the big bang, and for a good long time after that, until light could actually propagate. It seems to me that these time measurements are being talked about from a theoretical frame of reference of an observer standing outside of the universe watching it undergo The process. Can such a frame of reference exist? But it seems Einstein would object to such a frame of reference. If such a frame of reference cannot exist, then where are these timing numbers coming from?