Physics 3710 – Intermediate Modern Physics, Spring 2018
Newton and Maxwell
We have seen that simple magnetic forces are incompatible with Newtonian mechanics. There are far more profound incompatibilities between electromagnetism and Newton. In particular, Maxwell’s equations predict that an accelerating charge produces a time changing magnetic field, which, in turn, produces a time changing electric field, which, in turn, produces a time changing magnetic field, which, in turn, produces … . This self-sustaining production of magnetic and electric fields propagates away from the source charge at a finite speed given by 1 µ0ε 0 (in empty space), the numerical value of which is approximately 3x108 m/s. But, according to which observer? Is there lurking around someplace in Maxwell’s formalism an unstated preferred, inertial reference frame (the ether) in which the prediction is true (such as one at rest with respect to the “fixed” stars, for example)?
Peak, David, "Special relativity, 1" (2018). Special Relativity. Paper 1.