A Loss of Identity: the Birth of Quantum Statistics
This episode begins with a letter dated June 1924 [B1] written by a young Bengali. His name was Satyendra Nath Bose. The five papers he had published by then were of no particular distinction. The subject of his letter was his sixth paper. He had sent it to the Philosophical Magazine. A referee had rejected it [B2]. Bose's letter was addressed to Einstein, then forty-five years old and already recognized as a world figure by his colleagues and by the public at large. In this chapter I describe what happened in the scientific lives of these two men during the six months following Einstein's receipt of Bose's letter. For Bose the consequences were momentous. Virtually unknown before, he became a physicist whose name will always be remembered. For Einstein this period was only an interlude.* He was already deeply engrossed in his search for a unified theory. Such is the scope of his oeuvre that his discoveries in those six months do not even rank among his five main contributions, yet they alone would have sufficed for Einstein to be remembered forever.
Bose's sixth paper deals with a new derivation of Planck's law. Along with his letter, he had sent Einstein a copy of his manuscript, written in English, and asked him to arrange for publication in the Zeitschrift für Physik, if he thought the work of sufficient merit. Einstein acceded to Bose's request. He personally translated the paper into German and submitted it, adding as a translator's note: 'In my opinion, Bose's derivation of the Planck formula constitutes an important advance. The method used here also yields the quantum theory of the ideal gas, as I shall discuss elsewhere in more detail.'
The purpose of this chapter is not to discuss the history of quantum statistics but rather to describe Einstein's contribution to the subject. Nevertheless, I include a brief outline of Bose's work for numerous reasons. (1) It will give us some insight into what made Einstein deviate temporarily from his main pursuits. (2) It will facilitate the account of Einstein's own research on the molecular gas. That work____________________