My reply to "black hole mass" is why is the gravity of the original star multiplied simply because of size and/or density? When the large star explodes does it not release massive energy? Einstine tells us energy is mass, so by exploding the stars mass is some what reduced while it's gravity, in it's victory over fussion, crushes into the atomic level to leave no space between the nucleus [protons & nutrons] and the orbiting or vibrating electrons of each remaining atom. Yes, that's dense, but what is the science behind this atomic density creating this object's gravitational increase? To transform a star into a black hole, by definition, requires a large addition of the gravitational force. Another hic-up of Black holes is the singularity, or the actual object of black holes with no mass and emence gravity. WTF is a super massive black hole's singularity? We believe in the big bang because space did not exist until the bang so, in post bang terms, the singularity of the bang could have been 1000's of light years across. In pre space thought, the same thing could be called a single point. But space and time do exist now, no matter how intertwined, so what is the science behind size? Are stellar and supermassive black holes singularities? One last thing, if gravitons exist, would they reside within the atoms or among them?