Ehrenfest's adiabatic hypothesis in Bohr's quantum theory

TL;DR

This paper explores the historical development and influence of Ehrenfest's adiabatic hypothesis in Bohr's early quantum theory, highlighting its role and evolution in the context of quantum mechanics' foundations.

Contribution

It provides a detailed analysis of how Ehrenfest's adiabatic hypothesis was integrated into Bohr's quantum theory and its relation to the correspondence principle.

Findings

Ehrenfest's adiabatic hypothesis was crucial in Bohr's early quantum models.

Bohr referred to the hypothesis as the principle of mechanical transformability.

The hypothesis influenced the development of the correspondence principle.

Abstract

It is widely known that Paul Ehrenfest formulated and applied his adiabatic hypothesis in the early 1910s. Niels Bohr, in his first attempt to construct a quantum theory in 1916, used it for fundamental purposes in a paper which eventually did not reach the press. He decided not to publish it after having received the new results by Sommerfeld in Munich. Two years later, Bohr published "On the quantum theory of line-spectra." There, the adiabatic hypothesis played an important role, although it appeared with another name: the principle of mechanical transformability. In the subsequent variations of his theory, Bohr never suppressed this principle completely. We discuss the role of Ehrenfest's principle in the works of Bohr, paying special attention to its relation to the correspondence principle. We will also consider how Ehrenfest faced Bohr's uses of his more celebrated contribution to quantum theory, as well as his own participation in the spreading of Bohr's ideas.