One more thought on this topic.
According to the laws of classical electrodynamics, an electron orbiting in an orbit should emit electromagnetic waves and therefore quickly loses its kinetic energy, which means it “falls” onto the positive nucleus attracting it. And atoms, if not eternal, then, in any case, systems are quite stable. The young Niels Bohr put forward in 1913 the idea that saved the obviously doomed Rutherford model precisely by “canceling” the laws of electrodynamics for electrons in an atom, which rotate WITHOUT RADIATING, in “STATIONARY ORBITS.”
But there was no explanation of what it is or WHY electrons do not emit in such orbits.
THEY DON’T RADIATE and that’s it!
The microcosm is full of all sorts of “SPECIFIC QUANTUM” phenomena and features that we humans, macroscopic creatures, cannot understand!
I decided to try to answer this unpleasant question “WHY” anyway?
Due to its MOVEMENT in the plane of the orbit, an electron creates a magnetic field around itself, the intensity of which depends on its speed. The faster it moves, the more, the slower– the less. Visually, such a field would look like a kind of magnetic torus, a magnetic field “donut”. The maximum of the electron radiation diagram (let’s forget about Bohr’s brilliant idea for now) lies in the plane of the orbit. Zero radiation in the direction perpendicular to the plane, i.e. parallel to”axis” of the orbit.
What does an observer see when looking at the plane of the orbit, the “donut”, from the side? He sees a kind of electric charge moving in one direction, then the other. A electric charge oscillating back and forth.
Moreover, this charge moves not only at an unstable speed (FOR a SIDE OBSERVER!!!), but even with an unstable acceleration, unequally accelerated.. This generates the emission of electromagnetic waves.
SO, WHAT? Is such an oscillating “back and forth” charge of an electron enough?”
It’s NOT ENOUGH!
Its MAGNETIC FIELD should also CHANGE RAPIDLY! “Pulsating bagel”!
And I thought, well, if I had a magic wand, quite macroscopic, to hold it in my hand, I would wave it and eliminate this magnetic field, leaving only a rotating electron with its electric charge unchanged, and then WHAT would happen? Would there have been radiation or not?
My answer is that there would be no radiation without a magnetic field, there would only be one charge “oscillating” with an orbital rotation frequency. Radiation is possible only if there are two necessary and sufficient components – changing electric and magnetic fields! A CHANGING ELECTROMAGNETIC FIELD!
Yes, that’s the trouble – I don’t have such a wand!
And the atom HAS it!
The atom has managed to find something that does NOT cancel out the magnetic field of a moving charge, but COMPENSATES IT!
The magnetic moment of the electron itself!
Let’s imagine such a picture. The observer looks at an electron running in orbit from the side and sees not only its electric charge (for him, in his projection, running back and forth within the diameter of the orbit). but also the magnetic field he creates, which, again, he sees as a kind of transverse line of something, too, sometimes stopping (at the edges), then running back and forth again. Imagine that an electron in orbit moves “sideways”, that is, its own magnetic field, created by spin, rotation around its own axis, spin magnetic moment, is directed along its axis of rotation, which means perpendicular to the plane of the orbit, and it is directed so that this field completely cancels the magnetic field of the electron motion. We got what we wanted: An electric charge moving in orbit, WHICH DOES NOT CREATE A MAGNETIC FIELD! And since there is no magnetic field of motion in orbit, THERE is NO RADIATION OF ELECTROMAGNETIC WAVES!
To this assumption, anyone who knows physics within the school level will say: All this looks very beautiful and interesting, but UNREALISTIC, because the electrons in an atom move along the orbits of DIFFERENT DIAMETERS AND at DIFFERENT SPEEDS, while the electron’s spin and the magnetic moment that depends on it are CONSTANT! So, HOW does a constant magnetic moment manage to compensate for DIFFERENT magnetic fields of motion for different electrons in different orbits???
Answer: By changing the angle of inclination of the spin of the electrons to the plane of the orbit.
For electrons in external orbits, with their relatively low rotational velocity, the spin magnetic moment is “tilted” to the plane at a small angle and its projection onto the external field of motion is relatively small, but sufficient to fully compensate for it.
For electrons rotating rapidly in inner orbits close to the core, the spin and magnetic field are almost perpendicular to the orbital plane, and there their field is much larger and just as sufficient to compensate for their “high-speed” magnetic field!
Why are atomic orbital electrons so “arranged”?
I DON’T KNOW!
Okudzhava replied to this:
“That’s what Nature wanted!
Why? It’s none of our business!”
I think it’s OUR business, but we can’t find out everything at once!
So it turned out to be some kind of homegrown explanation for stationary orbits 113 years after Bohr’s brilliant idea!
Faciant meliora potentes.
25 IX 2026
