The Universe

Black Holes

How dense are black holes?

Based on Karl Schwarzschild’s formula for the radius of a black hole’s event horizon, the density of a black hole depends very strongly on its mass. A black hole the mass of Earth, for instance, would have more than two hundred trillion trillion times the density of lead. On the other hand, a black hole that is one billion times the mass of the Sun would have an average density much lower than the density of water.


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