Current producing electromagnetic force

Click For Summary
SUMMARY

The discussion centers on the phenomenon of electromagnetic force generated by electric current flowing through conductors. Participants explore the underlying principles, referencing Maxwell's Equations and the relativistic effects of moving charges. While empirical observations confirm the existence of magnetic fields, the fundamental cause remains elusive, with some arguing that current itself is a circular definition. The conversation highlights the complexity of defining magnetism and its relationship with electric fields, emphasizing the need for further exploration in quantum field theory and relativistic physics.

PREREQUISITES
  • Understanding of Maxwell's Equations
  • Familiarity with electric and magnetic fields
  • Basic knowledge of special relativity
  • Concept of charge and current in physics
NEXT STEPS
  • Study the implications of Maxwell's Equations on electromagnetic theory
  • Learn about the relativistic effects on electric and magnetic fields
  • Explore quantum field theory and its explanation of electromagnetic forces
  • Investigate the relationship between electric current and magnetic fields in depth
USEFUL FOR

Physicists, electrical engineers, students of electromagnetism, and anyone interested in the fundamental principles of magnetism and electric currents.

  • #31
Thank you very much. I understood it. Sorry for my english, but what is net effect? So moving the electron's electric field will have the strongest strength because of its speed of motion?
quote from phys.lsu.edu

Electrons, spinning as they orbit the nuclei of atoms, create magnetic fields. The direction of spin of each electron determines the direction of the magnetic field surrounding it.

I http://gickr.com/results2/anim_fa2cfba7-13bf-5784-7155-43e7058b1574.gif"
 
Last edited by a moderator:
Physics news on Phys.org
  • #32
waht? dfs
 
  • #33
what? Can you tell me why the direction of spin of each electron determines the direction of the magnetic field surrounding it?
 
  • #34
In classical electrodynamics, a spinning object is like a loop of current, which produces a dipole magnetic field:

Magnetic field of current loop

In quantum electrodynamics... ehhh... I'll let someone else tackle that. :rolleyes:
 
  • #35
jtbell said:
In classical electrodynamics, a spinning object is like a loop of current, which produces a dipole magnetic field:

Magnetic field of current loop

In quantum electrodynamics... ehhh... I'll let someone else tackle that. :rolleyes:

I am interested why the direction of spin of each electron determines the direction of the magnetic field surrounding it when the electric field lines are all same around the electron? So if it contracts itself when it moves from the front and back side, no matter which direction it moves the magnetic field will be same.
 
  • #36
  • #37
jtbell said:
Do you know about the right-hand rule for magnetic fields?

Magnetic fields of currents

I know the right-hand rule very well. But why it is like that? IT must be logical staments. What would you understand if somebody tell you: " the current is going into one direction and the magnetic field in other? "
 
  • #38
I suspected that you might ask that question! :rolleyes:

It comes from Ampere's Law, one of Maxwell's four fundamental equations for electric and magnetic fields. In differential form:

\nabla \times \vec B = \frac {\vec J} {\epsilon_0 c^2} + \frac {1}{c^2} \frac {\partial \vec E} {\partial t}

The "\nabla \times" is the "curl" operator. It has a specific "handedness" which leads to the right-hand rule for the magnetic field \vec B.

More stuff about Maxwell's Equations

Now, I'm going to guess that your next question will be, "Why is Ampere's Law like that?" which is equivalent to asking "Why are Maxwell's equations like that?"

My answer to that question is basically the same one that I've already given twice before, to similar questions:

https://www.physicsforums.com/showpost.php?p=1370588&postcount=4

You probably won't be happy with that answer, but it's the best I can do. :frown:
 
  • #39
Can somebody explain better and fundamental the creating of magnetic field around the electrons and its direction? what I see you are familiar with this, please help. Thank you very much, all.
 
  • #40
help pleaseeee.
 
  • #41
For an electron at rest, there is a Coulomb electric field and a magnetic dipole magnetic field, each given by standard textbook equations.
If the electron is moving with constant velocity v, a Lorentz transformation will give the E and B fields of the moving electron. This is done in advanced textbooks. It is a bit complicated because E and B are part of a second rank tensor, and the r coordinate also has to be Lorentz transformed.
 
  • #42
Why you thing that the electric field lines (electric force) will be
compressed?

If electric field lines are homogeneous space (seam) bonded to the
heterogenous seam of the 'particle',
{Or each the 'boundary condition of the other}
then homogeneous space, unlike
heterogeneous space, permits "two, or more, points to be in the same
place at the same time
(xref: Einstein - Botzmann vs. Fermi - Dirac statistics).

Therefore when [exterior sound] the
heterogeneous seam (boundary condition, fermion, 1/2 spin,
only one point in anyone place at one time) is
'displaced', it compresses the homogeneous space against itself. Since
homogenous space permits two points to be in the same place at the same
time, to what degree (xref: elasticity), or since homogeneous space
can be actively homogenous by definition seeking for all points in that
direction, or seam, or space, to actually be in the same place at the
same time, or how close to that ideal symmetry, THEN you would expect a
compression of the 'field' upon motion of the 'charge'.

I hadn't thought to be able to express it that way until your
question. Thanks.

But E-M charge, unlike gravity, is 'reverse' homogeneous, or heterogeneous, to itself, except 'opposite' charges are actively homogeneous to one another while remaining passively homogeneous to all other E-M neutral points . So besides the 'local' infinity of Euclid's zero dimensional point, is there a 'distant' infinity where [^] all the horizons meet? {But they are not parallel}. Is that the 'other side' of the local, zero dimensional, infinity? Is that what
E-M charge 'converges upon' regarding 'like' charge?

Rigid vs. elastic

Elastic in which direction on which side of the 'curve'? Deviation
from perfect symmetry expressed as a 'curve'.
 

Similar threads

  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 5 ·
Replies
5
Views
1K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 7 ·
Replies
7
Views
1K
  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 8 ·
Replies
8
Views
1K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 22 ·
Replies
22
Views
3K
  • · Replies 5 ·
Replies
5
Views
2K