Effect of magnetic field on radio waves

[ASHUPLC393]

Hello all

I have been trying for sometime now to find the effects that magnetic field has on radio waves (such as cell phone signals and wireless broadband signals). If anyone of you could guide me towards right direction, would be very much appreciated!

Thanks

Ashutosh

 

[vanhees71]

Within the classical theory of electromagnetism electromagnetic fields are not self-interacting, i.e., nothing happens to your radio wave, whether or not other electromagnetic fields are present.

In QED due to quantum effects the em. field becomes self-interacting, but this effect can be neglected for practical purposes with radio waves.

 

[Vanadium 50]

Easy. No effect.

 

[cragar]

really even in QED it self interacts?

 

[vanhees71]

Sure, that's the four-photon vertex. In leading order it's a box diagram with four external photon legs and electron-positron lines running around the box. It's a fourth-order effect inperturbation theory, i.e., of order $$\alpha^2$$ in the cross section. This is also known as the "Delbrück-scattering diagrams".

 

[Vanadium 50]

Let's get real here. Yes, there is an infinitesmally small QED effect. One that is absolutely undetectable with radio waves and magnets.

This is one thing I am growing to dislike about this forum. Someone asks a simple question with a simple answer, and a bunch of people confuse the OP with technically correct and utterly irrelevant complications. Needlessly complicating a problem does not make one look smart.

 

[vanhees71]

I emphasized already in my first reply that the QED corrections are negligible for all practical purposes. Nevertheless I think it's good to answer questions correctly according to our present knowledge of physics.

 

[Vanadium 50]

I disagree - he posted in Classical Physics, so a quantum mechanical answer is unlikely to be helpful. When someone wants to discuss balls and inclined planes in this section, do we insist on quantum mechanics? Furthermore, he gave explicit examples of macroscopic objects.

It does people no good to confuse them with overly complex answers that are not relevant to the information requested. Like I said, the goal is to make something complicated simple, not something simple complicated.