> Three properties completely describe a black hole: mass, spin, and charge.
So it's like an elementary particle?
So it's like an elementary particle?
Now, it appears that there is a huge change -- neutron star to a black hole -- from a small input, the 1 gram, that is, in math terms, there is a jump discontinuity.
There was something about the physics of the neutrons that kept the neutron star from shrinking to a singularity. Well, maybe that something also keeps that mass plus the 1 gram from shrinking to a singularity. That is, if there is no jump discontinuity, the inside of that black hole is essentially just like that neutron star.
Under GR it doesn’t matter since as the mass increases beyond a critical point an event horizon will form and all that matter will be compressed into a singularity regardless.
This "conversion" doesn't imply matter transitioning from one state to another. The main thing happening during transition to a black hole is that the light can't escape anymore - you see the star in one moment, and can't see it in another moment. Not necessarily because of some matter transition, but because it stops radiating light.
Singularity is a mathematical artifact, we don't know what's happening in the blackhole with matter and don't really care since it has no effect on the outside world.