Not being a physicist, but rather a mystic and Chemist, when I hear the singularity described as infinitely hot and dense, I say how can that be. Maybe they just mean extra hot and dense but outside the realm of our puny experience. Also, and unrelated, I have heard that if one walks in a straight line into the universe, they would return to starting point. If this were true, then when the singularity erupted, all energy went out in a straight line, to begin with. Wouldn't this mean that all the material of the universe will someday return to the singularity point of origin?? Given infinity of course.