Philosophy Explorer wrote:The popular Big Bang theory which explains much, doesn't explain things like what set off the posited singularity let alone how it could expand to the dimensions of our space and we lack direct evidence for the theoretical dark matter and dark energy.You ask when did the universe begin. But in what reference are you framing your question?
Decided to check the internet for updates and I've found a link giving three theories (I don't know if I'd buy Barbour's timelessly universe, the first two theories have more meat to them).
So the question is which of the three theories appeal to you? Which do you see have the strongest arguments going for it?
The link:
If you say the reference of our universe then it began when the universe began. There is no timescale beyond the universe that is also confined to the universe (it would be like a person within a movie asking when the movie began, the timescale of the movie cannot be used to deduce the beginning of the movie, you need to use the time-frame of the person watching the movie to determine the beginning of it). This would imply no real beginning since the concept of beginning has no applicability. By definition, beginning means:
"the point in time or space at which something starts." (google)
If you are assuming there was a time that extended before the universe, in other words a time in a more 'objective' frame of reference, then there can be no beginning to the universe. In the same way a balloon has no edge.
A simple deduction:
1) The universe having a beginning implies that our space-time scale had a beginning. 2) If our space-timescale had a beginning at time T on an external space-timescale B, then either space-timescale B had a beginning or did not have a beginning. 3) If it had a beginning then it would need to lie on some other space-timescale external to it.
Thus it would lead to an infinite regression of space-time beginnings implying no actual beginning for 'existence' itself (that is, anything that 'exists', in our frame of time and space or not).
If any one of the space-times didn't have a beginning, then it would still imply that existence always 'was' and 'will be' (the same thing applies for an 'ending' also.
So, in short, the universe never began. If you say it did, then that is only in regard to space time within our reference and thus no one could ever know when it began.