Erwin Schrödinger, a pioneer of modern quantum science, articulated in his 1944 book that scientists should contribute to their fields as a form of nobility. In What Is Life?, he invites readers to delve into the world of living organisms, moving away from the focus on inanimate atoms that brought him fame. Over approximately 90 pages, he transitions from one area of expertise to another, producing an influential work in popular science during the 20th century.

Based on a series of lectures delivered in Dublin in 1943, What Is Life? maintains a conversational tone while occasionally reflecting on deeper philosophical questions. However, Schrödinger’s core dilemma is framed within the parameters of physics: “How can phenomena occurring within living organisms be explained through physics and chemistry?”

To explore this, Schrödinger employs a physicist’s rationale. What Is Life? begins with a discussion on the minuscule and abundant building blocks of life and how they adhere to statistical physics principles. He clarifies that while physicists can derive averages from large collections, individual behavior remains unpredictable.

The laws of physics indicate that systems trend towards disorder and exhibit fluctuations. Yet, living organisms display remarkable order, akin to the intricate mechanisms of a clock. Schrödinger is captivated, noting that even minimal “genetic material” enables consistent reproduction and trait transmission, a phenomenon that poses questions in his analysis.

Written before the full understanding of DNA’s structure, Schrödinger contemplates the composition of this genetic material. Drawing from his studies on mutation inheritance and linking it to quantum concepts, he reflects on the possibilities of this genetic solidity and its quantum stability. His principal claim is that living entities require “negative entropy” to sustain order, necessitating a continual draw of organization from their environment. Schrödinger asserts that fully unraveling this enigma might demand new physics laws.

Published in 1944, What Is Life? garnered significant attention, inspiring numerous physicists to pivot towards biology. It frequently features in “best of” lists, appealing to general readers, yet chemists and biologists were less enthusiastic.

Nobel Prize laureate Max Perutz examined the extensive contemporary work that Schrödinger might have referenced for his inquiries. He noted that Schrödinger’s confusion about the regeneration of small genetic materials during cell division could have been mitigated with a better understanding of the roles of involved enzymes. Perutz also criticized the concept of negative entropy.

Recently, author Philip Ball indicated that Schrödinger might have gained deeper insight by engaging with ideas connecting entropy and information—such as Leo Szilard’s 1929 solution to Maxwell’s Demon paradox, where rising disorder is seemingly countered.

Despite valid criticisms, as a physicist, I find myself more aligned with Schrödinger’s perspective than those entrenched in modern genetics. In conversations with biophysicists, echoes of What Is Life? resound. Just last year, a researcher shared his ambitions to establish new physical laws addressing living systems. Another scholar sensibly noted, “If you’re in equilibrium, you’re dead,” capturing Schrödinger’s sentiments from the 1940s.

In 2021, biophysicist Rob Phillips at the California Institute of Technology asserted that What Is Life? should be viewed as “a manifesto on the frontiers of physics, signifying that every new phenomenon demands innovative concepts and ultimately results in new laws.” I concur. Although Schrödinger’s grasp of biology and chemistry was incomplete, his physicist’s intuition remains relevant.

Are physicists best equipped to decipher the precise mechanisms that distinguish the living from inanimate matter? It’s a philosophical question that future research may illuminate. This duality of excitement and frustration was poignantly addressed by Schrödinger over 80 years ago, grappling with the same challenges we face today.