Non-linear dynamics of classical hydrogen atom I'd like to know if there have been attempts in solving the full problem of the dynamics of a classical hydrogen atom.
Taking into account Newton equations for the electron and the proton and Maxwell equations for the electromagnetic field produced by these charges one obtains a higly non-linear set of coupled equations.
In such a nonlinear system could some feedback effects between proton and electron take place so to make possible a stable dynamics (or at least a dynamics unstable on such long time scales longer that we can consider hydrogen to be stable)? In this way the system's stability already obtained through quantum mechanics could be reproduced by a full classical approach!
P.s.: Please, as I know of the great successes that quantum theory has had since its birth, try not to answer the question telling how quantum mechanics wonderfully solves the problem.
P.p.s.: I'm also aware of the fact that electron should lose energy and that this should cause it to fall on the proton in a very short time, so please try to avoid also this argument.
I asked this question to understand if the oversymplifing hypothesis', which are fundamental in solving this problem (neglect proton's motion and, as a consequence, magnetic effects) and are quiet ubiquitous in physics, wouldn't mask the potential richness that could arise from mathematical complexity.
 A: No, it is not possible, and the argument is simple--- there is no dimensional parameter with unit of length, so if there were a stable equilibrium at one radius, there would be many such equilibria obtained by rescaling the original solution to a one-parameter family of solutions.
In fact, it is easier to see that the stable solution is for the electron to fall into the nucleus, just from thermodynamic considerations--- the state space for the electromagnetic field is infinite dimensional, so the most likely configuration is the electron sitting on top of the nucleus with infinite negative energy, and infintely much radiated energy in ultraviolet modes of the field.
In order to get a stable equilibrium, you need a constant with dimensions length, and using $\hbar$, you get such a constant. It is not possible to do this without introducing something like $\hbar$, just from dimensional analysis, independent of the quantum formalism.
A: It is not an "oversimplifying hypothesis" that allows us to neglect the proton's motion, it is simply a choice of reference frame. Since electromagnetism is a relativistic theory, this choice can have no effect on the physical predictions. How could the electron fall into the proton in one frame but stably orbit it in another?
