All Questions
Tagged with gravity electrostatics
27
questions
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
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
-7
votes
1
answer
96
views
Has anyone noticed that $G \times K\approx \frac{3}{5}$? [closed]
I have noticed that $$G \times K\approx \frac{3}{5}$$ Where $G$ is the universal gravitational constant and $K$ is Coulomb's constant.
Moreover, the approximation is so good that, taking into account ...
- 115
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 ...
0
votes
0
answers
29
views
Will antimatter fall upward in a gravitational force field? [duplicate]
A positively charged particle has a force acting along the electric force field. The contrary is true for a negatively charged particle.
Can we apply the same analogy for antimatter and say that ...
-1
votes
1
answer
191
views
How can the force between two charges change when the intervening medium is changed?
This is a common statement that the force between two charges changes when the intervening medium is changed however the gravitational force remains the same. But I have some problem with this.
When ...
- 8,230
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
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
1
vote
1
answer
191
views
Why does the inverse square law make impossible for an object to levitate throught a combination of distance action forces?
From the book Thinking Physics:
Suppose the moon had a negative charge. Then it would exert a repelling force on electrons near it. But the gravitational force of the moon exerts an attracting force ...
- 493
-1
votes
2
answers
355
views
Gauss Law in Arbitrary dimensions
What is the Gauss law in any arbitrary dimension "n" and how can one derive it?
- 469
0
votes
1
answer
197
views
How does gravity affect the permitivity of a dielectric?
Intuitively, I would not expect gravity to significantly affect electric permitivity. But, Consider a neutral black hole with a plastic sphere outside the event horizon. The protons-electrons of the ...
- 1,721
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
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
1
vote
1
answer
151
views
How can two charged black holes merge despite electrostatic repulsion?
I have read this question:
Collision of charged black holes
And it made me curious.
I understand that the charged black holes do have negative EM charge, and they repel.
This EM interaction and ...
- 29k
0
votes
1
answer
109
views
Is there any electrostatic waves for electrostatic force like the gravitational waves for gravity?
If sun suddenly disappears then it will take 8 minutes for earth to move out of its orbit due to the presence of gravitational waves.
What happens if proton in an atom suddenly disappears, will the ...
- 744
0
votes
2
answers
394
views
Why doesn't the gravitational force have a permittivity in its formula? [duplicate]
We know that the electrostatic force between two charges depends on the medium between the charges and its permittivity. Why, then, doesn't the gravitational force depend on the medium?
-4
votes
1
answer
236
views
In atoms which are more likely to attract first until they are together? Magnetism, gravity, electrostatic charge or other? [closed]
When do single atoms begin to pull together when they are close enough like 2 magnets?
Could 1 atom contain a magnetic field and would it be stronger than an atom's own gravity?
I know that atoms ...
- 1
-1
votes
1
answer
3k
views
What is the difference between an electric field and gravitational field? [duplicate]
Since the electrostatic field and the Newtonian gravitational field share a similar form: proportional to
$$
\frac{1}{r^2}
$$
Is there any qualitative difference between motions under the ...
- 209
1
vote
1
answer
77
views
Does Earth also move due to some electrostatic forces?
Does the earth experience some electrostatic forces due to other planets...which also make it move?
My question is..whether the earth also moves due to electrostatic force of attraction or only due ...
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
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
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
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
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
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
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
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