Abstract

One of the most influential physics books of the twentieth century was actually about biology. In a series of lectures, Erwin Schrödinger described how he believed that quantum mechanics, or some variant of it, would soon solve the riddle of life. These lectures were published in 1944 under the title What is life? and are credited by some as ushering in the age of molecular biology. In the nineteenth century, many scientists thought they knew the answer to Schrödinger’s rhetorical question. Life, they maintained, was some sort of magic matter. The continued use of the term ‘organic chemistry’ is a hangover from that era. The belief that there is a chemical recipe for life led to the hope that, if only we knew what it was, we could mix up the right stuff in a test tube and make life in the lab. Most research on biogenesis has followed that tradition, by assuming that chemistry was a bridge — and a long one at that — linking matter with life. Elucidating this chemical pathway has been a tantalizing goal, spurred on by the famous Miller–Urey experiment of 1952, in which amino acids were made by sparking electricity through a mixture of water and common gases. But the concept has turned out to be something of a blind alley, and further progress with prebiotic chemical synthesis has been frustratingly slow. The origin of life remains one of the great outstanding mysteries of science. To take up Schrödinger’s suggestion, a radical solution to the problem, ‘What is life?’ could be that quantum mechanics enabled life to emerge directly from the atomic world, without the need for complex intermediate chemistry. Life must have a chemical basis: organic molecules provide the hardware for biology. But what about the software? When Schrödinger asked, ‘What is life?’ he could already glimpse the central significance of the cell’s information storage and replication processes, even though the role of DNA and the genetic code was yet to be discovered..