# What is the fundamental explanation for the existence of Electrostatic force?

To explain my question in a better way I will first talk about gravitation!

Gravity is not a force and the effects of gravity are ascribed to spacetime curvature

My comments:

Gravity was explained in a better way by Einstein than by newton i.e If I ask newton what causes gravity and how can two objects placed far apart attract each other, he wouldn't be able to answer properly.But, Einstein can and he would give a lecture on General theory of relativity.

NOTE:

The major drawback of newton's theory of gravity is that it considers gravity to be a instantaneous force.Relativity puts a limit to the speed with which information can travel.

I think that electrostatic force can't be instantaneous, because there is a limit to the speed with which information can travel.

My question:

How do you explain electrostatic force?

Let's talk about electrostatic force between two opposite charges and gravitational force between two other objects.The electrostatic force follows the inverse square law similar to newtons law of gravity.But,we know that Newton's concept of force doesn't accurately describe gravity.Gravity is a consequence of curvature of spacetime.So,if I ask a question: what is the cause of gravitational force and why it isn't instantaneous, you could explain me General relativity.

But,what if I asked you: what is the cause of electrostatic force and why it isn't instantaneous ?...

To put it simply:

I just want to know if there is a prevailing theory which explains electrostatic force more fundamentally than the inverse square law and also the fact that electrostatic force isn't instantaneous

References:

https://www.youtube.com/watch?v=o1abyP4zfGg (time=3:22)

https://en.wikipedia.org/wiki/Gravity#General_relativity

• You may enjoy reading about Kaluza-Klein theory, which adds electromagnetism to GR via an extra (compact) space dimension. Roughly, charge is momentum in the extra dimension. Nov 2, 2018 at 12:07
• Before considering writing an answer, I should ask you a question. You've asked for a fundamental cause of electrostatic force, i.e., something the electrostatic force is a consequence of in analogy with "Gravity is a consequence of curvature of spacetime". So, it seems, you accept spacetime curvature as fundamental. Would you accept the electromagnetic field as fundamental in the same way as you do spacetime curvature? Nov 2, 2018 at 12:58
• @AlfredCentauri ..Do I accept that spacetime curvature is fundamental?...I'm not sure if it's 'the fundamental theory', but I agree that it's best theory we have,right now.I'm not sure if I would accept electromagnetic field as fundamental,but I would say it's the best theory that I know of.I just want to know if there is a prevailing theory which explains electrostatic force more fundamentally than the inverse square law and also the fact that electrostatic force isn't instantaneous. Nov 2, 2018 at 16:19
• Have you studied classical EM to a level that includes Maxwell's equations? If not, then I suggest reading up on that - since that is the resolution to the instantaneous action at a distance (which was solved in EM before it was solved for gravity in some sense). Nov 2, 2018 at 16:29

## 2 Answers

The theory that describes the electromagnetic field, quantum electrodynamics, is a Yang Mills gauge theory. This is an experimental observation. That is, there is no special reason why EM has to be a Yang-Mills theory, but if we describe it as a Yang-Mills theory we get predictions that match experiment.

However, once we make the leap that EM is a Yang-Mills theory everything else falls into place. For example Yang-Mills theories incorporate special relativity so we find that the EM field propagates at the speed of light. The force can be described as a curvature, just like gravity, though it is the curvature in an object called the connection rather than spacetime. Finally quantum electrodynamics has a gauge symmetry called $$U(1)$$ and the charge appears as the conserved property associated with this symmetry.

• Strictly speaking QED is not a Yang Mills gauge theory. The latter refers to gauge theories based on nonabelian gauge groups. QED as a gauge theory is based on U(1), which is abelian. Nov 5, 2018 at 4:19

Gravity explained ? Can I ask you a question then : why does mass cause a curvature in space time exactly ?

You see, in my humble opinion, you're just throwing the problem from a "why" to another. There will always be a fundamental "because that's the way nature works" at the bottom of any physical theory.

We could make up a world in our mind where masses don't curve space time. Or one where it curves it in a completely different way. We could then make sure that we derive mathematically coherent equations from there, and build a new out-of-this-world physics. Why is our world not like that ? Because.

The job of physicists is to describe our world as it is. So we have to start from an observation of what actually "is" and "isn't"

The point of calling something "fundamental", is that we won't try to explian it. we just take it as it is, because we observe that it does so. If I'm not miistaken, electrostatic is a fundamental force, so here it stops.

Bottom line is : if you ask me "why gravity?", I'll answer you "dafuck do I know ?". And I hate speaking on behalf of Einstein, but I suppose his answer would be somewhat similar. He just described it in another more geometrical way, that's it.

In general, I believe that "why" is quite often a question that regards metaphysics more than physics. Physics focuses more on "how" kind of questions (this is of course an oversimplified statement but I think you get my point)

• ..I understand what you want to say,but that's not what I'm looking for.I want to know if there's a theory that explains: electrostatic force more fundamentally than the inverse square law and also the fact that electrostatic force isn't instantaneous.A physicist describes/explains the world as it is,so how does he explain/describe the electrostatic force and the fact that it isn't instantaneous? ...That's what I'm looking for.You don't address my questions at all in the answer and that's the reason I'm downvoting your answer Nov 2, 2018 at 8:48
• I mostly wanted to point out the misconception that Einstein's idea "explained" gravity. It didn't. It just gave a new picture of it, leaving the question of the 'origin' untouched Nov 2, 2018 at 9:51
• A comment would have done the job,but still it was good point.I'm editing to add the point of yours! Nov 2, 2018 at 9:53
• haha the point doesn't bother me, do as you please. A comment has limitations in characters and my point didn't fit into it. I also felt it was a very important point to guide your question so that I didn't hesitate to upgrade it as answer Nov 2, 2018 at 9:56
• Oh I get it.Anyways thank you for your time,it was a good point!...please feel free to provide any small points also,they might help me: make my question better and informative. Nov 2, 2018 at 9:59