Black holes get less dense as they gain mass - assuming I didn't drop a factor of 2 or τ, a 1 solar mass black hole has a density of 147 quadrillion tons per cu

Black holes get less dense as they gain mass - assuming I didn't drop a factor of 2 or τ, a 1 solar mass black hole has a density of 147 quadrillion tons per cubic meter. A black hole of 100 million solar masses had density of only 14.7 tons per cubic meter (for reference, lead is 11.3 Tn/m3 and osmium is 22.6 Tn/m3). So a sphere of 100M (actually >81M) solar masses of osmium would collapse into a black hole without even having to compress under it's own gravity first. You'd need 384 million solar masses for something with the density of water.