There was not a world-wide flood? Good God, all of that over-whelming physical evidence must be a figure of anyone's (even atheist and agnostic scientists) imaginations.
Well, err, there is no such evidence. Furthermore there is only enough water to fill the oceans, in case you haven't noticed. To flood the lands would require a huge increase in terrestrial water. It would have to come from somewhere and go somewhere, not of this earth.
There is no scientific evidence of a great worldwide flood, and there is no scientific explanation for such a thing either. Therefore no serious scientist accepts the hokey myths of the bible. Those stories are for children.