Question

Did time begin? Will it end?

Please provide a long answer to the question(s) above, using diagram and formula whenever possible

Answer 1

As some have pointed out, time doesn't 'exist' independent of space. But that's not clear enough. Fundamentally, time is an emergent phenomenon. The 'experience' of time emerges from the interaction of space and matter.

This becomes more evident with relativity - your experience of time changes with your interaction with space. Therefore, a clock in a spaceship doesn't experience time the same way you on planet earth do. Similarly, to the extent you consider BBT to be the correct model for the beginning of the universe, time, in the beginning, was not the same as it is today -- you would have experienced it differently if you were there to see it. To put it differently, there is only one way for anyone to experience time -- to record the change in some entity, be it a clock or a decaying atom or the propagation of em waves. If everything in the universe simply stopped changing, you cannot experience time. So effectively, time 'stops'. Similarly, if the universe started to implode on itself in a big crunch, time would still continue, because the universe continues to change. But your experience of time -- your interaction with space/matter, might possibly change.