Schrödinger’s Collected Papers On Wave Mechanics

The True Nature of The Quantum rules

“In this paper I wish to consider, first, the simple case of the hydrogen atom (non-relativistic and unperturbed), and show that the customary quantum conditions can be replaced by another postulate, in which the notion of “ whole numbers ”, merely as such, is not introduced. Eather when integralness does appear, it arises in the same natural way as it does in the case of the node-numbers of a vibrating string. The new conception is capable of generalisation, and strikes, I believe, very deeply at the true nature of the quantum rules.”

Erwin Schrödinger

Source: Archive.org