Here's today's special relativistic EM question. Can the Thomas precession be shown to be a special case of the perihelion advance of relativistic elliptical orbits? Any ideas? Here's what's going on: We've been deriving the special relativistic orbit of a charged particles around another fixed charged particle. At the end of the day, you wind up with a perihelion advance which is a fancy way to say that major axis of the elliptical orbit won't stay put. It swivels around, (orbits), the charged particle as well. The advance angle of the major axis winds up being\\ $\delta\phi = 2\pi\left[\left(1 - \dfrac{\kappa^2}{l^2}\right)^{-1/2} - 1\right]$ Which is very, very, similar to the Thomas angle for the spin precession, or gyroscopic precession along a circular orbit at special relativistic speeds:\\ $\delta\phi = 2\pi\left[cosh\left(w\right) - 1\right]$ $= 2\pi\left[\left(1 - \dfrac{v^2}{c^2}\right)^{-1/2} - 1\right]$ In the expression...