What is Life

In 1943, one of the fathers of quantum mechanics, famous for his equation and his cat, Erwin Schrödinger, turned his attention to a problem that was seemingly simple but defied an easy answer. As World War 2 raged, he published a book titled What is Life?

Based on a series of lectures given in Dublin, the book’s theme was to answer the question: “how can the events in space and time which take place within the spatial boundary of a living organism be accounted for by physics and chemistry?”

In other words: What is Life? Or, from a physicist’s point of view, how can life arise from inanimate matter.

Much of the lecture discussed the requirement for genetic material and some sort of encoding as well as how life related to thermodynamics — the laws governing energy, heat transport, and disorder.

Although their success largely depended on Rosalind Franklin’s X-ray diffraction experiments, Francis and Crick would also credit Schrödinger’s work for inspiring their research resulting in the discovery of the DNA double helix.

Schrödinger’s primary insight is that life creates order from disorder. In a universe governed by the 2nd law of thermodynamics, that all things tend to maximal disorder, living things maintain small enclaves of order within themselves. Moreover, if you look down to the atomic level, you find that the interiors of living things are extremely chaotic. Heat and molecules diffuse through rapid motion. Everything seems random. Yet the living thing persists, turning all that small scale chaos into large scale order.

Human built machines, by contrast, attempt to maintain order down to the smallest relevant levels. Microchips, for example, depend on orderly transfer of data down to nanometers. Precision machine tools, likewise, function because they have an exact specification at nearly the molecular level. The result is that human tools require careful protection and maintenance and break easily when subjected to the elements.

Life, on the other hand, has withstood the elements for billions of years precisely because it is able to build order out of chaos.  READ MORE