As I suspect most people, I have always associated Bremsstrahlung with the breaking energy release of moving charged particles. However, a little thought opens up many questions. As the following link points out Breaking Bremsstrahlung occurs due the interaction of the EM field associated with a charged particle in motion with other particle fields. http://www.astro.utu.fi/~cflynn/astroII/l3.html The problem is this. 1 - If I place EM detectors around an isolated charged particle (static electricity) and then accelerate another particle then there exists a relative velocity between such particles. According to Relativity it doesn't matter which particle we look at each now has velocity and hence should have an associated EM field. The facts are however, that only the particle which underwent the physical acceleration (F = ma and forces) has such an EM field. The detectors around the static charge will not see any pulse of EM during the acceleration of the other particle nor any field due to relative velocity between particles. The concept of "Relative" velocity is therefore a flawed view of motion. There exists "Apparent" motion and "Actual" motion. While it is not obvious to an observer which is which, there does exists the ability to distinguish between such types of motion and that is where SRT failed. 2 - Einstein arugued that there is total equivelence between uniform acceleration and being restrained in a accelerating gravity field. The absence of Bremsstrahlung of static charged particles in a gravity field disputes that view. Comments welcome. Please Register or Log in to view the hidden image!