Physics Question #1310

Michal Jaworski, a 18 year old male from Calgary asks on March 6, 2003,

A black hole is a central point the size of a pinhead where a huge amount of mass is concentrated. If, by the two equations F=(GMm)/r^2 and F=(kQq)/r^2, mass and charge are in the same relationship in universal law, can there be such a thing as a huge charge compressed to a very tiny point just as a black hole is?

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The answer

William George Unruh answered on March 6, 2003

a) Like charges repel, while like masses attract. Thus it is hard to bring charges together, and it would take an infinite amount of energy to concentrate charges into a point.

b) A black hole is more complex than just a huge mass squeezed into a time volume. Because gravity alters the way inwhich time and space are defined, a black hole is not a mass squeezed into an arbitrarily small size. Rather one gets a horizon formed at a radius of 2GM/c^2. Because electromagnetism does not involve space or time alterations, you do not get the same thing happening for charges.

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