# Conducter in magnet fild - curent

1. Mar 8, 2004

### jhirlo

I can't get it imy head why are electrons set in motion in magnet fild - that changes, or why do they move in not strait motion in stady magnetic fild.
I know about Lorentz force, but i dont know why, and why that specific direction?

I've tryed to correlate it to electrons magnetic fild and spin, but i haven't ended with conclusion, i just need an explanation.

Plus to me, moving through magnetic fild (conducter like in generators), do not seems same as standing still, and changing magnetic fild ?

p.s. what is particle that carries magnetic fild ? Photon maybe, but it can't be it goes in non starit lines (certainly not photon i'm seening when i'm looking in this screen :) )

p.s.s. does gravitation attratcts magnetic field ?

2. Mar 10, 2004

### turin

Lorentz force. Don't confuse it with Faraday's law.

The Lorentz force is a fundamental (as far as I know) characterization of nature. Almost as fundamental as 3 extended spatial dimentsion, or something like that. This is assuming you are wondering why electromagnetism exists, that is, why charge interacts with the electromagnetic field.

Perhaps you mean, why is there a vxB term in the Lorentz force law? Well, that is a consequence of invariance. Relativity explains away most of the mysterious character of electromagnetism, i.e. it composes Maxwell's equations into 2 instead of 4, and the Lorentz force is just a result of a Lorentz boost on the Coulomb force. Of course, there will always be a "why?" in the back of your head, if you are fundamentally curious.

In the classical theory, the dynamics of charged particles are governed by the Lorentz force regardless of whether or not they have spin.

If someone has told you that these two phenomena are identical, then don't listen to them.

Well, let me ellaborate with the most obvious counterexample. Moving through a constant magnetic field can be transformed to the rest frame in which the magnetic field will still not appear to change in time. So, how can that be equivalent to being stationary in a magnetic field that <i>is</i> changing in time?

I don't understand what you're asking here.

Sort of. The magnetic field has energy. Energy is an interaction term for gravitation.

Last edited: Mar 10, 2004