All Questions
Tagged with gravity electrostatics
27
questions
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
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
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
8
votes
5
answers
2k
views
Do electric fields in a capacitor add to its weight?
So this article got me thinking: https://www.scientificamerican.com/article/do-electric-charges-and-m/
It states that according to GR, the energy in an electric field should curve spacetime and ...
- 319
7
votes
2
answers
1k
views
If I suddenly store a lot of energy in a small space, this induces spacetime curvature. Does that create gravitational potential energy?
Let us presume that I have a capacitor and suddenly charge it. This induces a (miniscule) spacetime curvature. Nearby objects would experience a gravitational attraction and by extension would have ...
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
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
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
3
votes
0
answers
111
views
Black hole nucleus in hydrogen
The hydrogen atom gets the spectrum it has because you analyze the Schrodinger equation in spherical symmetry with the potential given by $V=-\frac{1}{4\pi\epsilon_0}\frac{e^2}{r}$. Yet the same ...
- 183
3
votes
0
answers
90
views
Modeling the formation of a stellar system and matter accretion
I am trying to figure out what do I need to know to properly simulate the creation of a solar system from a particle cloud with random distribution of hydrogen atoms.
Being more of a programming ...
- 131
2
votes
3
answers
364
views
How come we talk about gravitational potential energy and not gravitational potential?
With regards to gravity the equation learned is $$U=-\frac{GMm}{r}$$
And the relationship to force is $$F=-\frac{dU}{dr}$$
In electrostatics we instead talk about electric field and electric ...
- 1,760
2
votes
2
answers
3k
views
What is the effect of temperature on electrostatic-gravitational balance?
We have two identical massive metal spheres at the same temperature at rest in free space. Both have an identical charge and the Coulomb force [plus the black-body radiation pressure if the ...
- 478
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
2
votes
1
answer
117
views
Is there an experiment showing that the warping of space affects the shape of an electrostatic field? [duplicate]
General relativity assumes that space itself is warped by gravity, which is what gives rise to the shapes of the paths followed by objects subject to a gravitational field.
If space itself truly ...
- 533