In my electromagnetism course it says that the magnetic force has a relativistic origin. This would be because it depends on the frame of reference used and its magnitude is only a significant fraction of the Coulomb force when the moving particles are moving at backlight speed.
But it also says that gravity and electrical force are similar in many ways, such as the formula and potential energy and the like. So is there a relativistic variant of gravity? For example, a force that ensures that 2 masses moving at the speed of light still exert the same force on each other despite the length contraction and the change of relativistic mass?
Answer
Dear Jannik,
That “the magnetic force has a relativistic origin” is worded a bit strange to me. The magnetic field does indeed depend on the inertial frame, but so does the electric field! (The electric field and the magnetic field are the components of a four-dimensional tensor that transforms between different inertial systems according to the Lorentz transformations.) Indeed, since the electric and magnetic field components transform together, it is clear that only a relativistic theory can correctly describe electromagnetism. to give. I suppose that’s what is meant by “relativistic origin”.
Not so for gravity. There is no “magnetic variant” of gravity, not even in the relativistic description of gravity (general relativity).
The fact that gravity and the electric force are similar in many ways is because both forces are transmitted by massless bosons (photons and gravitons). This gives both forces an unlimited interaction distance (the 1/r² law). But photons and gravitons are different in other ways, for example their spin (photons have spin 1; gravitons have spin 2).
Kind regards,
Philippe Tassin
Answered by
prof. Dr Philippe Tassin
Professor of Physics (Chalmers University)
http://ikhebeenvragen.be/help.jsp
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