All Questions
17
questions
5
votes
1
answer
302
views
EM 4-potential vs gravity 4-potential?
In classical field theory, the electrostatic and gravitational fields have very similar differential forms:
$$\vec \nabla\cdot \vec{E}=\frac{\rho}{\varepsilon_0}$$
$$\vec \nabla\cdot \vec{g}=-4\pi G\...
- 1,616
-3
votes
3
answers
310
views
Why do gravity and electricity sometimes obey inverse square laws over the same distance scale?
Is this a chance mathematical coincidence or is there a good physical explanation for it?
user381695
0
votes
0
answers
56
views
Poincaré inverse square law unification
A while back, I came across a claim that was something like this: Poincaré said that no two fundamental force laws could have the same mathematical form such as $1/R^2$; that no two fundamental force ...
- 1
-3
votes
3
answers
113
views
How can the unit of Newtons measure both gravity and electromagnetism?
For context, I was thinking about forces. Force is the mass of the particle multiplied by the acceleration it undergoes. There are different kinds of forces, for example, gravity and electromagnetism. ...
- 161
3
votes
2
answers
190
views
Why isn't electromagnetism incompatible with special relativity?
The notion that newtonian gravity is incompatible with special relativity is often suggested by declaring the familiar equation $$F_g=\frac{Gm_1m_2}{|\vec{r}_1(t)-\vec{r}_2(t)|^2}$$ and stating that ...
- 103
0
votes
0
answers
66
views
What is the lengthscale where electric force and gravity are comparable?
Basically the title. I came across this question while going through old exams. I thought that electromagnetism is stronger than gravity by 40 orders of magnitude more or less, at all scales, so this ...
- 716
0
votes
0
answers
43
views
Why the force is inversly proportional to the square of distance? [duplicate]
Lesser the distance higher the force of attraction.but why it is the square of distance?And also the reason i guess for this force is the attraction force between atoms ( electrons of one atom and ...
- 21
3
votes
4
answers
393
views
How strong would the electromagnetic field of the earth and the planets would have to be, in order to mimic the effects of gravity? [closed]
How strong would the combined forces of electromagnetism on the earth and planets need to be, to mimic, and therefore, replace gravity?
- 43
7
votes
4
answers
4k
views
Can Newton’s law of gravitation be derived from Coulomb’s law? [duplicate]
I’m casually learning physics and have noticed that Newton’s law of gravitation and the electrostatic force formulas look similar. I’ve asked this question before but would really appreciate another ...
- 257
1
vote
0
answers
82
views
If there were positive and negative masses similar to positive and negative charges, would there be some kind of gravitational magnetic force?
Coulomb's law is very similar to Newon's law of gravitation. But as we go deeper into electromagnetic phenomena we see that it is very complex compared to newtonian gravitation. For example if the ...
- 529
-1
votes
1
answer
3k
views
What is the difference between an electric field and gravitational field? [duplicate]
Since the electrostatic field and the Newtonian gravitational field share a similar form: proportional to
$$
\frac{1}{r^2}
$$
Is there any qualitative difference between motions under the ...
- 209
21
votes
2
answers
3k
views
Is Newton's universal gravitational constant the inverse of permittivity of mass in vacuum?
Is it possible to consider Newton's universal gravitational constant, $G$, as inverse of vacuum permittivity of mass?
$$\epsilon_m=\frac {1}{4\pi G}$$
if so, then vacuum permeability of mass will be:...
user26425
10
votes
4
answers
14k
views
Similarity between the Coulomb force and Newton's gravitational force
Coulomb force and gravitational force has the same governing equation. So they should be same in nature. A moving electric charge creates magnetic field, so a moving mass should create some force ...
- 1,975
3
votes
5
answers
4k
views
What was wrong with action a distance?
It is usually said that the idea of fields was introduced (electric and magnetic fields) in electricity and magnetism after Coulomb's law to cure the conceptual problems of action at a distance.
...
- 17.1k
4
votes
1
answer
3k
views
Gravity force strength in 1D, 2D, 3D and higher spatial dimensions
Let's say that we want to measure the gravity force in 1D, 2D, 3D and higher spatial dimensions.
Will we get the same force strength in the first 3 dimensions and then it will go up? How about if ...
- 75