In the early 1940s Schrödinger worked at the Institute for Advanced Studies in Dublin. One day he met P. P. Ewald, another German theoretician, then a professor at the University of Belfast. Ewald, who had been a student in Göttingen before the First World War, gave Schrödinger a paper that had been published in the Nachrichten der Gesellschaft der Naturwissenschaften in Göttingen in 1935 (Yoxen, 1979). The paper was by N. W. Timoféeff-Ressovsky, K. G. Zimmer and Max Delbrück (1935), and was entitled ‘The nature of genetic mutations and the structure of the gene’. Apparently Schrödinger had been interested in that subject for some time, but the paper fascinated him so much that he made it the basis of a series of lectures at Trinity College, Dublin, in February 1943 and published them as a book in the following year, under the title What is Life? (Schrödinger, 1944). The book is written in an engaging, lively, almost poetic style (for example, ‘The probable life time of a radioactive atom is less predictable than that of a healthy sparrow’). It aroused much interest, especially among young physicists, and helped to stimulate some of them to turn to biology. I was asked by the organizers of the Schrödinger Centenary Symposium to assess its significance for the development of molecular biology.

The Timoféeff-Ressovsky, Zimmer and Delbrück paper

This paper forms the basis of Schrödinger's book. It covers 55 pages and is divided into four sections.