A question about the fundamentality of magnetism

  • Context: Graduate 
  • Thread starter Thread starter mpatryluk
  • Start date Start date
  • Tags Tags
    Magnetism
Click For Summary
SUMMARY

The discussion centers on the fundamental mechanics of magnetism, specifically how moving electric charges generate magnetic fields. It is established that the electromagnetic interaction is a fundamental force, and the magnetic fields produced by moving charges do not require a net charge. Special relativity plays a crucial role in understanding these phenomena, particularly in how the reference frame affects the perception of magnetic fields. The conversation also touches on the role of photons as force carriers in electromagnetism, distinguishing between virtual and real photons.

PREREQUISITES
  • Understanding of electromagnetic interaction
  • Basic knowledge of special relativity
  • Familiarity with quantum field theory
  • Concept of virtual and real photons
NEXT STEPS
  • Study the principles of special relativity and its implications on electromagnetic fields
  • Explore the concept of electromagnetic interaction in detail
  • Investigate the role of photons in quantum field theory
  • Learn about the behavior of magnetic fields in different reference frames
USEFUL FOR

Physicists, students of electromagnetism, and anyone interested in the fundamental principles of magnetism and its relationship with electric charges.

mpatryluk
Messages
46
Reaction score
0
I'm sorry if I may be asking an unanswerable question here, but I've looked all through the forums and the internet to find a satisfying answer to why moving electric charges create a magnetic field.

I'm not trying to ask why electrical attraction/repulsion exists, as I take that as a fundamental force. But i am wondering which specific mechanics cause the relative motion of a flow of electrons to create an attractive or repulsive force on objects we deem magnetic.

I guess my main question is:
What is it about the movement aspect that is so special?

When electrons are flowing through a copper wire, the net charge on the wire is still neutral at any given point, isn't it? So does the electron movement somehow create a temporary net charge because of the fact that the individual electrons and their static fields are changing position relative to the magnetic object? Or does magnetism have nothing to do with positive/negative net charge?As a note i thought of after: Photons are the force carriers for electromagnetism, right? So magnetism must be caused by some difference in how the photons affect a target when the electron that emits them is moving?
 
Last edited:
Physics news on Phys.org
I'm not trying to ask why electrical attraction/repulsion exists, as I take that as a fundamental force.
The (more) fundamental interaction is the electromagnetic interaction. We do not know why the electromagnetic interaction exists, that is just an experimental result. The magnetic fields of moving charges are a direct result of that. Special relativity is very important in that respect.
Photons are the force carriers for electromagnetism, right?
In quantum field theory, with virtual photons, yes.
So magnetism must be caused by some difference in how the photons affect a target when the electron that emits them is moving?
You are mixing virtual and real photons here.

When electrons are flowing through a copper wire, the net charge on the wire is still neutral at any given point, isn't it?
Right.
So does the electron movement somehow create a temporary net charge because of the fact that the individual electrons and their static fields are changing position relative to the magnetic object?
That is a very good question, and the answer is: it depends. It depends on your reference frame, and special relativity is necessary to see this in detail.
Or does magnetism have nothing to do with positive/negative net charge?
You do not need net charges for magnetic fields.
 
  • Like
Likes   Reactions: 1 person
mfb said:
The (more) fundamental interaction is the electromagnetic interaction. We do not know why the electromagnetic interaction exists, that is just an experimental result. The magnetic fields of moving charges are a direct result of that. Special relativity is very important in that respect.
In quantum field theory, with virtual photons, yes.
You are mixing virtual and real photons here.

Right.
That is a very good question, and the answer is: it depends. It depends on your reference frame, and special relativity is necessary to see this in detail.
You do not need net charges for magnetic fields.

You've helped ease my mind quite a bit on the subject. I'm the kind of person who can't delve into a subject unless i understand the "why", and it helps to know that it's more of a fundamental occurrence than something with a simple explanation i was missing. Thanks a lot, now i can progress!
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 20 ·
Replies
20
Views
5K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 23 ·
Replies
23
Views
5K