@jojokp,
jojokp wrote:i understand, but what evidence is there that space and time did not exist prior to the BB?
Your question is a little like asking if there is any evidence of ocean-water outside of the ocean? And the answer would be NO, because it's only ocean-water BECAUSE it's in the ocean.
Space and Time are aspects of the Cosmological model that we call the BB. They are defined by that model and bounded by that model.
There may be a "different" Time/Space outside of the BB model, but the particular Time/Space defined within this model, can not exist outside of this model.