Black Hole Radius

[Evil_Tom]

Hello,

Does the radius figure for black holes indicate the size of the event horizon or the size of the singularity?

The only way I've found of creating a black hole is to increase the radius of an object (not the mass or density). Really to a black hole, radius is nearly irrelevant isn't it, as it occupies a singularity with no radius? I assume a real singularity cannot be simulated with a computer due to the problems with infinity (infinite gravity) so I can understand that it's the event horizon in the radius field.

By increasing the mass of stars I find they just supernova. Once I increase the mass of the supernova remnant it usually explodes into fragments. When I set massive stars to age they just whimper out and create remnants and not black holes. What size of star is required for this? Also I do not seem able to create a star in 'realistic' mode that'll turn into a black hole through ageing. Is this to be expected?

[Physics_Hacker]

Singularities are infinitely small, so no, the radius is not that, it's the event horizon, I believe.

You have to decrease the radius of an object by such an amount that it becomes a black hole, not the other way around. Like to make Earth a black hole, you'd have to crush it down to about the size of a pea.

[Deadpangod3]

I think he means that the massive stars are not creating black holes when their lives run out, which indeed would be a bug, unless the developers have not implemented that yet, but yeah, stars should be creating black holes when they die if they're big enough.