Our concept of time, as a rigid line of absolute sequence, is a property of a universe that simply does not exist.
Sequence is dependent on point of, and nature of observation. Time is a fuzzy, pliable pipe, not a line, but the idea of continuous, unlimited time travel in a negative direction is fantasy to any denizen of this universe.
I don't see time as a rigid line. I see time as motion and momentum, but, I'm not a physicist, so...
Thanks for the response e-s