B & E Waves: Symmetrical or Non-Symmetrical?

  • Context: Graduate 
  • Thread starter Thread starter jmatejka
  • Start date Start date
Click For Summary

Discussion Overview

The discussion centers on the nature of electric (E) and magnetic (B) waves in electromagnetic (EM) theory, specifically questioning whether these waves can be non-symmetrical to one another. Participants explore the implications of symmetry in the context of wave propagation and the generation of EM waves, including the relationship between charge movement and photon emission.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Technical explanation

Main Points Raised

  • One participant notes that B and E waves are typically illustrated as symmetric but questions if they can ever be non-symmetrical, suggesting that this would contradict their inductive relationship.
  • Another participant explains that while B and E are perpendicular and phase-shifted at long distances from an EM source, they may relate differently closer to the source or in anisotropic media.
  • A participant expresses confusion about the relationship between the E and B fields, specifically asking if they can be non-symmetrical in size and shape, reiterating the inductive nature of the fields.
  • One participant mentions a conversation with a retired physics professor who suggested that the permeability of the medium could lead to non-symmetrical waves, inviting further thoughts on this idea.
  • There is a discussion about the emission of photons when generating EM waves, with one participant asserting that waving a charged comb does release photons, while another suggests that the classical Maxwellian approach is more suitable for such experiments.

Areas of Agreement / Disagreement

Participants express differing views on the symmetry of E and B waves, with some suggesting that non-symmetrical conditions can arise under specific circumstances, while others maintain that their inductive relationship implies symmetry. The discussion remains unresolved regarding the conditions under which non-symmetrical waves may occur.

Contextual Notes

Participants mention various conditions that could affect the symmetry of E and B waves, including proximity to the source and the properties of the medium, but do not reach a consensus on these points. The discussion includes assumptions about the nature of EM wave generation and photon emission that are not fully explored.

jmatejka
Messages
126
Reaction score
1
B and E are typically illustrated in a symmetric phase shifted oversimplified sine wave(s).

Are the B and E waves ever non-symmetrical to one another? This seems to make no sense to me, as they induce one another.



Also EM waves do not always involve the release of photons, correct? I was once told the easiest way to make a Electromagnetic wave was to comb your hair(get a charge on comb), then wave the comb up and down. By definition this movement of charge generates an Electomagnetic wave, no photons released here as charge moves up and down, correct?

Thanks for any clarification!
 
Physics news on Phys.org
B and E are perpendicular, shifted in phase, as you said, etc. only at long distance from EM source, where you may see them as a propagating flat wave approximation. Closely to the antenna they may be related differently. They may also not be perpendicular if the wave propagates through anisotrobic medium (the one rotating polarisation, like glucose solution for visible light)

Of course, waving your comb you release billions of photons! Waving the comb you emit some EM wave (honestly: not a strong one...), which carries the energy. This energy may be seen as a number of photons.
Anyway, for such experiments classical Maxwellian electrodynamics seems to be much more suitable approach.
 
Thanks! I originally had a EMP question regarding Greater E field than B field. This seemed to make no sense to me.

I actually should have said are B and E ever non-symmetrical in size and shape (under the curve). This would make no sense since one induces the other.
 
Last edited:
I had this conversation with retired U.C.C.S. Physics Professor Bobby Bracewell last weekend. He thought Permeability of the medium could also create non-symmetrical waves. Any thoughts?
 

Similar threads

  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 15 ·
Replies
15
Views
4K
  • · Replies 10 ·
Replies
10
Views
3K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 12 ·
Replies
12
Views
4K
  • · Replies 23 ·
Replies
23
Views
3K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 35 ·
2
Replies
35
Views
11K
  • · Replies 1 ·
Replies
1
Views
2K