A new series from the TLS, appraising the works and legacies of the great thinkers and philosophers

Despite devising both the defining equation and the defining thought experiment of quantum physics, Erwin Schrödinger was never comfortable with what he helped to create. His “Schrödinger’s Cat” paradox, published in 1935, was an attempt to expose the flaws in the physics that flowed from his eponymous equation. And yet, that cat – both dead and alive – has become an icon of quantum physics rather than a warning against its shortcomings.

Schrödinger was born in Vienna in 1887. He was an exemplary schoolboy, displaying a startling ability in all his classes. He taught himself English and French in his spare time, and nurtured a love of classical literature. By the time he enrolled at the University of Vienna in 1906 he was focused on physics, but still took the time to learn a great deal of biology, which informed his later work – contributions that were cited as inspirational by the discoverers of DNA.

The work for which he is remembered requires some context. As with all science, an individual’s contributions to physics rarely occur in a vacuum, and a host of other figures set the stage for Schrödinger’s entrance. His seminal work began with his attempts to resolve a central mystery of the nascent quantum theory. Max Planck had discovered that the precise nature of the radiation emitted by hot objects could only be explained if the energy of the radiation came in discrete lumps that came to be known as quanta. Planck found this somewhat distasteful, as there was (and still is) no explanation for why this should be so. Einstein subsequently proved this energy quantization to be real with his discovery of the photoelectric effect, for which he won the 1921 Nobel Prize for Physics.

The Danish physicist Niels Bohr built on Planck’s work, offering an appealing model of the atom in which the electrons surrounding the atomic nucleus can sit only at particular distances from the nucleus. The energy involved in moving between these orbits corresponds to Planck’s quanta of energy radiated by the atom, and the position of the atomic levels are such that their circumference allows a whole number of wavelengths, when the electron is represented by a wave. Though appealing, Bohr’s model has several shortcomings. No mechanism exists by which the electrons can jump,…