This is probably extremely basic physics that I don't know, but I'm still going to ask:
Say in hydrogen, according to the Bohr model the electron is "really" orbiting the proton, and as a consequence would have to continuously emit radiation thus losing kinetic energy and should then fall towards the proton. So this is obviously not correct, except that I don't know/understand why it's circular motion necessarily mean it has to emit radiation... ?
From Maxwells equations we know that accelerated charged particles emit em waves.
This can be seen from the electromagnetic wave equation, where a second derivative of the electric field is involved. If the second time derivative of the charge density is nonzero, also the second time derivative of the electric field is non vanishing and electromagnetic waves are formed. A circular motion is a accelerated motion (towards the center of the circle) and therefore it should emit em waves.
Note that in Bohr's model the fact that electrons on quantized trajectories do not emit radiation is an postulate.
