Writing that inspired a generation of scientists

A long exile and a short book that set the agenda for postwar science and the start of molecular genetics

Seventy-five years ago in September 1939 an Austrian refugee travelled across England to Dublin. His German passport marked him as an enemy alien, but a letter from Éamon de Valera ensured him and his family a safe passage. And thus the Nobel physicist, Erwin Schrödinger, came to Ireland.

Schrödinger would spend 16 years here, later calling it his “long exile”. He came as the first professor of physics at the newly established Dublin Institute for Advanced Studies, and while here he wrote a short book that would set the agenda for postwar science and the start of molecular genetics.

Published 70 years ago, and titled simply What Is Life?, it is arguably one of Ireland's most important contributions to modern science. The book inspired a generation of scientists, especially those who worked on military research during the war, to switch to biology postwar.

If the first half of the 20th century belonged to physics and chemistry, the second half would be the era of biology. And that is largely thanks to Schrödinger’s book.


The book actually began as a series of three lectures that Schrödinger gave in Dublin in 1943. The audience of 400 ranged from invited schoolchildren, to de Valera and his Cabinet. It’s intriguing to think of such interest in science lectures in Dublin then, and one wonders what many of them made of it all.


In the lectures, and in the subsequent book, Schrödinger speculates about the nature of inheritance. At the time, scientists thought that the molecule involved in genes and in carrying genetic information must be a protein.

As a physicist, Schrödinger was attempting to deduce from first principles what the mechanism of inheritance might be. Significantly, Schrödinger proposed that the genetic information must be carried in a “code-script”, and by a protein crystal. Not any regular crystal – such as table salt – but rather an “aperiodic” or irregular crystal. Surprisingly, for the man acknowledged as the father of quantum mechanics, he envisaged a kind of clockwork mechanism, something almost old-fashioned and Newtonian.

In setting out the questions that needed to be answered, Schrödinger was setting the agenda for the start of modern molecular biology.

His ideas were timely. They coincided with the development of information theory in the nascent field of computer science. His multi-disciplinary mix of physics, chemistry, statistics and biology appealed to scientists who had worked in multi-disciplinary teams during the war. And his questions appealed to the ex-military researchers who were looking for new, peace-time challenges.

Those inspired by What is Life? included two physicists: Maurice Wilkins, born in New Zealand of Irish parents, had spent his war years working on radar technology and the Manhattan project and Englishman Francis Crick had also worked on weapons research. Across in the US, Schrödinger also influenced a young college student, James Watson, to switch from ornithology to genetics. The field was set.

In 1952, an elegant experiment proved that Schrödinger was right: the genetic molecule was indeed an aperiodic crystal. But it wasn’t a protein, instead it was something called deoxyribonucleic acid, better known by its acronym DNA.

The race was now on to crack the code-script.


Within a year, Watson, Crick and Wilkins, aided by X-ray photographs of DNA crystals that Rosalind Franklin had taken, pieced together

DNA's double helix.

. From this structure it was easy to see how the code-script might work, and how the double helix might zip together in an almost clockwork manner. Schrödinger was right again. Shortly after, Crick and Watson wrote to Schrödinger in Dublin, acknowledging the important role his book had played in their success.

Modern editions also include a few pages of “autobiographical sketches”, that Schrödinger wrote after he left Dublin and returned to Vienna in 1956. Here he describes his Dublin years as “a wonderful time . . . Nowhere else could we have lived through the Nazi war still untouched by problems that it is almost shameful.”

So it was that Éamon de Valera’s invitation to Schrödinger 75 years ago paved the way for one of the most profound books in modern biology. Mary Mulvihill is a science writer. She tweets about Irish geek heritage at @IngeniousIE