As far as my knowledge goes, Reciprocity property is explained by the theorem. I had to give a topic name, so I mentioned reciprocity theorem. I'll rephrase it. Thank you for the link. I'll go through it :)
I do know that in practical two electrons in the same orbital do not collide with each other because if that happens atom wouldn't be stable. But how can they exist without colliding one or the other time.. I'm sure there is an answer for it and hope I get it...
So stark effect and zeeman effect affect the degeneracies of orbitals... But what about the atom then? How can it be stable? Moreover, stark effect and zeeman effect contributed for the evolution of degenerate orbital concept (I suppose)...