The discussion revolves around the density of black holes in relation to their mass and size, particularly questioning whether larger black holes are less dense than smaller ones. Participants explore theoretical aspects of black hole density, including the implications of singularities and event horizons.
Participants express differing views on the relationship between black hole size and density, with some supporting the idea that larger black holes are less dense while others question this notion. The discussion remains unresolved regarding the implications of density in relation to black holes and singularities.
There are limitations in the discussion regarding the assumptions made about density, the definitions of volume and mass in the context of black holes, and the complexities of black hole geometry that are not fully addressed.
As I said in the previous post the "size of a black hole" is generally taken to be the diameter of its event horizon. The actual geometry of the black hole is pretty involved - but as a simplification, imagine that all of the mass of the black hole is concentrated in a singularity, a point, at the center. The size of the event horizon is the sphere around that point where light cannot escape. If you double the mass at the center, the distance to the event horizon increases so the total volume of the black hole increases. That total volume will more than double. So, heavier black holes are less dense because they can enclose more empty space.Hoophy said:I heard that a black hole can have a extremely low density. Also I heard that the bigger the black hole the lower the density. This does not make much sense to me, is it true? And if so can someone explain why?