All Questions

65
votes
4answers
5k views

How exactly is a normal force exerted, at the molecular level?

I've been surfing the web for quite a while, finding the answers I would need, but couldn't find a convincing one. First of all I need to remind you that this a very long/continuous question, so ...
0
votes
0answers
29 views

How do interaction terms appear in the Lagrangian?

How does forcing the Lagrangian to be invariant under $U(1)$ group give rise to the electromagnetic interaction term?
2
votes
1answer
51 views

What is meant by “Since the exchange of (mesons) occurs frequently, the nuclear force is stronger than the electromagnetic force”?

This is from a book written by Y. Nambu. What role does the mass of mesons (versus mass of photons) have in making the strong force strong? How does this relate to "frequent exchanges" of mesons? ...
-1
votes
1answer
41 views

Is there a way for light to be reflected out of the usual plane of incident?

Is it possible for use to apply a potential or magnetic field to the surface of the media, so that the light being reflected out of the plane of incident? i.e. Compare to an initial "vertical" plane ...
0
votes
0answers
25 views

Is a magnetic force caused by a curvature of something? [duplicate]

If gravity is not a force, but a manifestation of spacetime curvature, what about other forces? What about magnetic force (or Lorenz force)? Is it not a force, but a manifestation of the curvature of ...
2
votes
1answer
56 views

Can the EM field self-interact in the Standard Model?

Since the EM field is a linear combination of the electroweak $U(1)$ gauge field and one of the $SU(2)$ gauge fields, does this mean that it has self-interaction terms carried over from the ...
0
votes
1answer
62 views

Unification of the strong and electromagnetic interaction

Is it somehow possible to theoretically unify the electric charge in electromagnetic interaction with the colour charge in the strong interaction and how these charges give rise to the respective ...
0
votes
2answers
83 views

A place of space-time where the only fundamental interaction will be the gravitational forces: does make sense?

We know that there are four (fundamental forces) fundamental interactions of nature, this Wikipedia. I'm curious about if we can speculate that there exists a place of the space-time in which, after ...
1
vote
1answer
342 views

Electric force much stronger than gravitational force? [duplicate]

It is commonly said that the electric force is much stronger than the gravitational force. Indeed, Coulomb's constant $k_e$ is much larger than the gravitational constant $G$ but they are measured in ...
1
vote
1answer
105 views

Does electric and magnetic field interact?

Can electric field or magnetic field interact with an Electromagnetic radiation? And can 2 electromagnetic radiations interact with each other? Rather than the interference effect.
1
vote
0answers
31 views

How fundamental electromagnetic interaction occurs in electrostatic case (say, between two resting electrons )?

Interaction between two resting charges (electrostatic case - in electrostatic field) is anyways electromagnetic (because we have only 4 fundamental interactions). Electromagnetic interaction means ...
-4
votes
2answers
356 views

Do neutrons interact with electro-magnetic fields? [closed]

Does neutrons interact with electromagnetic fields? If yes, what kind of interactions would they undergo?
2
votes
1answer
79 views

Speed of electromagnetic interactions

We know that electromagnetic waves fly with the speed of light, but my question not about waves. Consider a very strong electromagnet that creates a substantial field 3 meters away. Then we send a ...
0
votes
1answer
144 views

Strength of gravitational waves vs. electromagnetic waves

If the recent gravitational wave's energy had reached us as visible light, how bright would it have been? Stackexchange complains about the form and brevity of the question so i add something... if it ...
0
votes
0answers
246 views

Repulsive part of interatomic/intermolecular potentials: Pauli, Coulomb or both?

We know that if we take two atoms/molecules, their interaction energy shows a short-range attractive part and a medium-range attractive part. One popular way to schematize this interaction is to ...
15
votes
3answers
4k views

Why do Neutrinos pass through us but photons can't pass through us? [duplicate]

Neutrinos have no mass and no charge. Therefore, they are not deflected by the other particles in our body and pass through us. Photons too have no mass and no charge, but why are they being deflected ...
15
votes
2answers
5k views

If the strong nuclear force is stronger than electrostatic repulsion, why don't nuclei collapse into a point?

Today in class we were discussing the strong nuclear force, and our teacher was explaining about how the strong nuclear force counteracts the repulsion force between protons in a nucleus. When asked ...
3
votes
0answers
61 views

How exactly are the relative strengths of gravity and electromagnetism quantified? [duplicate]

I've often heard it said that gravity is much weaker than electromagnetism, and after looking at several questions on SE, I feel that I've got at least a qualitative handle on the concept -- gravity ...
1
vote
0answers
165 views

Why is gravity so weak? [duplicate]

How does physics explain the enormous disparity between the gravitational scale and the typical mass scale of the elementary particles? In other words, why is gravity so much weaker than the other ...
2
votes
2answers
637 views

Why does the classical electrodynamics Lagrangian density equation have a “field” term and an “interaction” term?

On Wikipedia's page on classical electrodynamics, they state the Lagrangian density equation as follows \begin{equation} \mathcal{L} = \mathcal{L}_{\text{field}} + \mathcal{L}_{\text{int}} = -\frac{...
0
votes
1answer
1k views

Gravitational force and Electromagnetic force?

I found this interesting note in one of my textbooks, The enormous strength of the electromagnetic force compared to gravity is evident in our daily life. When we hold a book in our hand, we are ...
0
votes
1answer
290 views

How do magnetic objects exhibit attraction/repulsion across empty space?

Magnets will attract or repel over a distance before physically touching each other. What makes this effect possible? My best guess is that the forces generated by the angular momentum of the ...
1
vote
0answers
101 views

Exotic coupling

I have encountered the minimal coupling between a field and charges before $$H = \frac{1}{2m}(p-qA)^2,$$ whereby I am considering the classical case. The description minimal leads me to ask if ...
0
votes
1answer
275 views

Which interaction is the responsible for long-range magnetism?

I am taking a course on solid state physics. The class is mostly based on Ashcroft-Mermin's "Solid State Physics". Yesterday I sat for an exam and there was a question I couldn't answer: "Which ...
2
votes
2answers
328 views

Interaction speed between electric charges and magnetic materials

Einstein said that the speed of a matter in universe cannot exceed the speed of light. Is it correct for electric force transmission speed from one electric charge to other one? What is transmission ...
1
vote
2answers
921 views

How do magnets work?

I've read a classbook on the field theory (including EM): it perfectly describes quantitive patterns in EM-theory, but I have no luck understanding how and why it works. I mean, magnetic substances ...