# Why is a black hole with q>e singular?

#### Loren Booda

Black holes have the properties of angular momentum, mass, and charge. Since electromagnetism is a much stronger inverse-square force than gravity, and like charges repel, wouldn't a black hole with charge q>e avoid singularity?

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#### jcsd

Gold Member
No, this is how a black hole is formed, i.e. the gravitational pull of the star becomes greater than the degenracy pressure caused by electromagnetism and the like.

#### Loren Booda

Even when a mass is collapsed beyond degeneracy to neutronium, any net charge its eventual "singularity" harbors still retains the property of predominant repulsion.

#### Creator

Originally posted by Loren Booda
Black holes have the properties of angular momentum, mass, and charge. Since electromagnetism is a much stronger inverse-square force than gravity, and like charges repel, wouldn't a black hole with charge q>e avoid singularity?
Well Loren,..who says inverse square law holds true inside a singularity?

Creator

#### Loren Booda

Creator,
One must achieve the singularity first. In other words, can you derive a minimum net charge/mass relation for collapsing matter to attain a black hole?

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#### Creator

Originally posted by Loren Booda
Creator,
One must achieve the singularity first. Is there a minimum net charge/mass for attaining a black hole?
Beats me; I've not heard of such a calculation. However, even before going singular 1/r^2 likely becomes deficient.

Creator

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#### bogdan

What does q>e mean ?

#### jcsd

Gold Member
Originally posted by Loren Booda
Creator,
One must achieve the singularity first. In other words, can you derive a minimum net charge/mass relation for collapsing matter to attain a black hole?
There is no minimum mass needed for a black hole (though obviously one formed by steallr evolution has a minimum mass)and charge doesn't enter into it.

#### Loren Booda

bogdan, q>e means the net collapsing discrete charge, q, is at least 2 times the electon charge, e, in order for like charges to repel.

jcsd, the minimum mass for a black hole is M*, the Planck mass. This quantity derives from the absolute radiative constants c, G and h. Only quanta or their composites weigh less.

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