Re: Gravitomagnetic monopole?

On Mar 3, 3:59 pm, Erik Max Francis <m...@[EMAIL PROTECTED]
> wrote:
>
> In electromagnetism, there are two sources of charge:  electric and
> magnetic.  Electric charge is the one we're all familiar with and is
> usually just called, of course, charge.  Magnetic charge is called
> poles, but they always show up in equal and opposite pairs, hence
> "dipoles."  A hypothetical isolated magnetic charge, or pole, is a
> monopole -- and "monopole" only makes sense if you're talking about some
> kind of field charge that only comes in equal and opposite pairs.

Mathematically, a monopole is well defined even when there is only one
type of charge - the monopole moment of a distribution of matter is
its total mass, and the monopole moment of a distribution of electric
charge is its net electric charge (note that an isolated particle
still counts as a distribution - it is just a delta function
distribution).

Luke