All Questions
Tagged with gravity electrostatics
8
questions
10
votes
6
answers
2k
views
What prevents the accumulation of charge in a black hole?
What prevents a static black hole from accumulating more charge than its maximum? Is it just simple Coulomb repulsion?
Is the answer the same for rotating black holes?
Edit
What I understand from ...
- 1,261
21
votes
2
answers
3k
views
Is Newton's universal gravitational constant the inverse of permittivity of mass in vacuum?
Is it possible to consider Newton's universal gravitational constant, $G$, as inverse of vacuum permittivity of mass?
$$\epsilon_m=\frac {1}{4\pi G}$$
if so, then vacuum permeability of mass will be:...
user26425
7
votes
1
answer
469
views
How do aspherical gravitational monopoles look like?
I was recently pointed by laboussoleestmonpays to a beautiful paper from some time ago,
Aspherical gravitational monopoles. Alain Connes, Thibault Damour and Pierre Fayet. Nucl. Phys. B 490 no. 1-2 ...
- 134k
5
votes
3
answers
848
views
Paradoxical interaction between a massive charged sphere and a point charge
Suppose we have a sphere of radius $r$ and mass m and a negatively charged
test particle at distance d from its center, $d\gg r$. If the sphere is electrically neutral, the particle will fall toward ...
- 478
11
votes
2
answers
513
views
Why is nonzero net charge density incompatible with the cosmological principle?
In an answer to a question about the overall charge-neutrality of the universe, benrg writes,
A nonzero net charge density is incompatible with the cosmological
principle. Unlike the gravitational ...
rob♦
- 91.5k
6
votes
1
answer
7k
views
Trying to understand Laplace's equation
I'm struggling here so please excuse if I'm writing nonsense.
I understand that the gravitational potential field, a scalar field, is given by $$\phi=\frac{-Gm}{r}$$
where $\phi$
is the ...
- 3,059
5
votes
3
answers
414
views
Why is the universe charge-neutral?
The positive charges (such as from the protons) of the universe are almost neutralized by the negative charges (such as from the electrons).
Is there an explanation for this neutrality? Does it ...
- 4,452
2
votes
0
answers
53
views
Gravitationally-driven electrical potential differences in conductors
This question asks
Free electrons in a metal are attracted by gravity towards Earth. So why don't they lay down to the bottom of the conduit, like sediment at the bottom of a river?
The current ...
rob♦
- 91.5k