# If the Singularity in a Black Hole Has Infinite Mass

## Main Question or Discussion Point

If the Singularity Has Infinite Mass, How Does Merging With Another Black Hole Create "Suoermassive" Black Holes? Infinite Plus Infinite Is Infinite. No Increase.

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Wait. That Would Be Infinite Gravity Instead?

Staff Emeritus
2019 Award
If the Singularity Has Infinite Mass
It does not.

berkeman
Mentor
If the Singularity Has Infinite Mass, How Does Merging With Another Black Hole Create "Suoermassive" Black Holes? Infinite Plus Infinite Is Infinite. No Increase.
A black hole has finite mass. You are probably thinking of the density of the singularity...

http://en.wikipedia.org/wiki/Black_hole
Singularity
Main article: https://www.physicsforums.com/wiki/Gravitational_singularity [Broken]
At the center of a black hole as described by general relativity lies a https://www.physicsforums.com/wiki/Gravitational_singularity [Broken], a region where the spacetime curvature becomes infinite.[54] For a non-rotating black hole, this region takes the shape of a single point and for a https://www.physicsforums.com/wiki/Rotating_black_hole [Broken], it is smeared out to form a https://www.physicsforums.com/wiki/Ring_singularity [Broken] lying in the plane of rotation.[55] In both cases, the singular region has zero volume. It can also be shown that the singular region contains all the mass of the black hole solution.[56] The singular region can thus be thought of as having infinite https://www.physicsforums.com/wiki/Mass_density [Broken].

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It has a specific mass, but theoretically infinite density. The concept behind a black hole is if you rolled a ball on a trampoline it would warp the surface, and it would pull other balls to it. A black hole is essentially a hole in the trampoline.

PeterDonis
Mentor
2019 Award
Infinite Gravity
A black hole doesn't have infinite gravity either.