Magnetic Field: Mass, Charge, and Motion

AI Thread Summary
The discussion centers on the relationship between magnetic fields, mass, and electric charge. It clarifies that magnetic fields are properties of the electromagnetic field, while mass is an intrinsic property of particles. The conversation highlights that photons, which are massless, travel at the speed of light and do not possess relativistic mass in a conventional sense. Misunderstandings about photons approaching the speed of light and the concept of relativistic mass are addressed, emphasizing that the invariant mass of photons remains zero. Ultimately, the relationship between magnetism and mass is complex and not straightforwardly defined.
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How magnetic field associate with mass...
from the experiment we know that this is due to electric charge...
So is this another property of charge which come in front when charged particle goes in motion?...

Is this associate with mass or electric charge or with both?
 
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I don't really understand your first question... there is no connection between the mass and the magnetic field... the one is a property of particles the other is a part of the electromagnetic field.
Some magnetic field is equivalent to an some electric field in another reference frame (or in Special Relativity, the electric and magnetic field are just the two sides of the same coin -electromagnetism)
 
In field theory, it has been described that the particle of electromagnetic field is a photon. Although photons are massless particles, but they can have relativistic mass when they approach the speed of light. So, in this sense there might be some relationship between magnetism and mass.
 
but they can have relativistic mass when they approach the speed of light
That is wrong in every phrase... The mistakes:
1."they approach the speed of light." That is actually wrong. Photons don't approach the speed of light, they run with the speed of light, because they are massless.
2."they can have relativistic mass." The relativistic mass is not a nice quantity to talk about, because it is frame-dependent and so physicists hardly ever use it. The rest/invariant mass is the way to walk. The rest mass of the photon is 0 and in fact you can't find any reference frame in which the photon would have some mass.
Even if you wanted to find the relativistic mass (although that's wrong to try for particles traveling at null-wordlines), you wouldn't be able to, because it's m_{rel}= \gamma m_{inv}... if m_{inv}=0 then you are getting infinity times zero.
 
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Susskind (in The Theoretical Minimum, volume 1, pages 203-205) writes the Lagrangian for the magnetic field as ##L=\frac m 2(\dot x^2+\dot y^2 + \dot z^2)+ \frac e c (\dot x A_x +\dot y A_y +\dot z A_z)## and then calculates ##\dot p_x =ma_x + \frac e c \frac d {dt} A_x=ma_x + \frac e c(\frac {\partial A_x} {\partial x}\dot x + \frac {\partial A_x} {\partial y}\dot y + \frac {\partial A_x} {\partial z}\dot z)##. I have problems with the last step. I might have written ##\frac {dA_x} {dt}...
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