What Is Life? by Erwin Schrödinger

What Is Life? by Erwin Schrödinger
What Is Life? by Erwin Schrödinger

What is Life? by Erwin Schrödinger is a very short book in which the author discusses vital biological concepts such as the idea of a ‘code’ of life. The author’s main aim was to explain how living things go about their life without obeying the second law of thermodynamics. From public lectures that the physicist had delivered to an audience of about four hundred, the book was never expected to become popular when Schrödinger decided to compile his presentations. However, the nature of the topic handled, and the author’s arguments made it a success that propelled him to becoming a Nobel Prize winner.


What do you think of when you hear the word life? Do you start thinking of the many living organisms roaming around our planets, or do you picture the things you do that make life worth living? From a biologist’s point of view, life is the aspect of existence responsible for processing, reacting, acting, evaluating, and evolving via growth. While defining life, the key consideration that differentiates it from non-life is the former’s use of energy to facilitate physical and conscious development. Thus, life can be considered as anything that grows, and will eventually die.

Life is a mystery that has always attracted the attention of many people. It got a physicist, Erwin Schrödinger, to focus on it and even published the book – What is Life? Even though many consider this book as an attempt to fuse physics and biology, it contains something far more important. It introduces vital points in the history of biology, most of which are still referenced today when talking about life.

The code of life

This book was written at a time when scientists believed that proteins, rather than DNA, were the hereditary materials. However, Erwin Schrodinger did not allow this consideration to cloud his arguments. He preferred using the term ‘pattern’ of an organism in reference to what the biologists called ‘the four-dimensional pattern.’ This comprised of the entire ontogenetic development from the fertilized egg all the way to maturity. The structure of the fertilized egg determined the whole four-dimensional pattern. He further explained that it is only the nucleus of the fertilized egg that was responsible for this structure.

According to the physicist, it was important for genetic material to comprise a non-repetitive molecular structure. He argued that the molecular structure (chromosomes) housed some code-script which influences the whole pattern of the individual’s development and functioning in a mature state. A complete chromosome, explained Erwin Schrödinger, contained the full code. Thus, there is a rule in the fertilized egg which could be used to characterize the earliest stage of an individual.

This became the very first suggestion that genes followed a specific code. Even though the author’s point of view was completely different from many others before him, he successfully incepted the idea. His shortcomings were the failure to suggest a correspondence between various segments of the code-script and the idea of biochemical reactions.

At the most basic level, living organisms are designed to conserve and amplify information so that they survive in their current environment, as well as pass it to future generations. These become the essence of natural selection and evolution. We can do this because of our genes. The genes are the code of life that Erwin Schrödinger had talked about.

Code of life in everyday life

We can read the code of life literally in every way of our daily activities. Genome sequencing has become the norm in biology and medical research.  Sequencing involves studying genomes and encoded proteins. The information harnessed from sequencing makes it possible for scientists to spot gene changes, associations with phenotypes and diseases, as well as identify key drug targets. Given that each person is unique, we all have our own ways of developing diseases and responding to treatments, lifestyle, and nutrition. With each improvement in technology, it becomes possible to develop an accurate treatment by looking into the individual and disease genetics.

Even as we do all these things, one is left to wonder whether it would have been possible had it not been for Schrödinger’s lecture 75 years ago. His decision to turn the lectures was even more phenomenal as it gave people an easy point of reference. Iconic 20th-century scientists like Maurice Wilkins, Francis Crick, and James Watson, among others, confess to drawing inspiration from Schrödinger’s work.

The distinction that really matters

Throughout the book, the author tackles vital concepts, all in a bid to expound on his idea of the code of life. He talks about mutations where he explains the fact that there are exceptions in the resemblance of children and parents. This difference is a clear sign that genes undergo some kind of change. These changes are referred to as mutations. Erwin Schrödinger explains that the mutations are inherited as perfectly as the original. He gives different examples to drive his point home.

However, there are some sections of the book that require one re-read  in order to comprehend why Erwin Schrödinger would make such a claim. For instance, when he says that a molecule is viewed as a solid = crystal. The reason for this is that the forces used to unite atoms that make up a molecule are the same as those that unite atoms making up a true solid. He further argues that we draw the permanence of the gene just from this concept of solidity.

As much as most readers might be quick to agree to his arguments, this is a point of view that is sure not to settle well with most biologists. At the time of writing, Erwin Schrödinger believed that atoms are bound together by Heitle-London forces. However, detailed studies have shown that atoms of molecules are linked together via chemical bonding (a chemical reaction).

Reconciling physics and biology

In most cases, physics and biology are often looked at as two completely different disciplines. Whereas biology is the study of living organisms, physics entails the study of matter and laws of nature.

What many do not know is that the two disciplines are more related than you can imagine. Who would have thought that a physicist like Erwin Schrödinger would present ideas revolutionary to the field of biology? Even though a bigger percentage of his works had revolved around physics, his lectures on the code of life got biologists into thinking and even embraced the idea of DNA. His choice of terminologies may have been metaphorical to some, but it got biologists thinking about something they had no real understanding of.

In 1944, biologist Oswald Avery published a paper demonstrating the existence of DNA as the genetic material. However, this paper did not immediately get scholars and reviewers talking about a code-script in DNA as expected. Part of the reason Avery’s work failed to spark excitement was the line of thought that DNA was a boring molecule with a repetitive structure. Schrödinger’s work clearly showed that it was not true. Erwin Chargaff’s entry into the picture, inspired by Avery, presented the letters A, T, C, and Gas, the base of a DNA molecule. The combination of these letters differed from one species to another, suggesting that DNA is actually more exciting, something Erwin Schrödinger had tried to explain in his publications.

We cannot afford to isolate biology from physics. When the two fields are combined, it presents an opportunity to learn more about biological systems at an atomic or molecular level. When biological questions are viewed from the quantitative perspective, a scientist is able to understand patterns taking place in living organisms. Physics is the base of biology. Living organisms are a part of the universe which comprises of space, time, matter, and energy. Without these, the organisms would not exist.


There are different life forms on the planet Earth, making it interesting to discuss this topic. Carbon-based studies reveal that life existed on Earth for 3.5 billion years. With such facts, one is left wondering whether or not extraterrestrial life exists as well. However, that wasn’t the focus of Erwin Schrödinger in his book – What is Life?

The physicist provided a deeply-thought discussion on life as though he was a biologist himself. He became a bridge between physics and biology. It is not surprising that after reading this book, many physicists took their time to understand the science of living.

This book is not just for scientists. Even though it requires you to concentrate a little bit harder to stay on track, it has important life-changing arguments. The author’s brilliance at striking a balance among the fields of science (Biology, Physics, and Chemistry) is intriguing.


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