4 ms·
Does that vector also have fixed magnitude? It's magnitude is called 'mass' (or 'rest mass'/'invariant mass' if you want to differentiate it from the concept o
by cygx 6y ago
Does that vector also have fixed magnitude?
It's magnitude is called 'mass' (or 'rest mass'/'invariant mass' if you want to differentiate it from the concept of 'relativistic mass', which probably should be retired).
This means we have
four-momentum = mass * four-velocity
whereas
three-momentum = gamma * mass * three-velocity
- alexpetralia 6y agoNot sure if you will find this comment, but I'd be very curious to hear what the magnitudes of "four-force" and "four-potential" are as well! My layman's research suggest these are, respectively, "electric charge" and "current"?
- cygx 6y agoThat doesn't sound right to me. Note that four-force is a generic concept not limited to electromagnetism. Current is the source term of Maxwell's equations, which connect it to the potential via the d'Alembert operator.