View source for Purturbation

==Full Title==

for discrete?

from Born

What we shall do, is to bring the classical laws for the perturbation 
of a mechanical system, caused by internal couplings or external 
fields, into one and the same form, which would very strongly suggest 
the formal passage from classical mechanics to a 'quantum mechanics'. 
For this, the quantum rules as such will be retained essentially unchanged; as multiples of the action quantum h there will appear the 
action integrals of the unperturbed system, 4) which is assumed to be 
separable and non-degenerate. On the other hand, mechanics itself 
will undergo a change, in the sense of a transition from differential 
to difference equations, as already exhibited by Bohr's frequency 
conditions. In the simple case of non-degenerate systems, there seems 
then to be no room left for arbitrariness. 

==References==

[[Category: Physics]]