Hedonic Calculus

Bit more of a technical one today, assuming some background in multivariable calculus. Our starting point is going to be Maxwell's equations for a magnetic field B and an electric field E in the absence of any charges: We've got these constants mu_0 and epsilon_0 baked into the equations and these are known as vacuum permeability  and vacuum permittivity  respectively. I'm not entirely sure what that means but the important point is that these are features of the universe and everyone can agree on their value. (Oh look, a gun hanging on the wall).

Picking up where the last one left off, still dedicated to BK

 This post is dedicated to BK. I've procrastinated this one because it's a huge topic and one quite important to me, learned from good teachers.