Erwin Schrödinger and the Quantum Revolution
2012 Bantam Press £25.00hb 336pp
Not many life stories in physics involve Nazis, illicit sex, a strange cat and the genetic code. Thus, a new biography of the great Austrian physicist Erwin Schrödinger is always of interest, and with Erwin Schrödinger and the Quantum Revolution, veteran science writer John Gribbin does not disappoint.
Many Physics World readers will be aware of Walter Moore’s 1992 biography Schrödinger: Life and Thought, which remains the definitive text on this colourful quantum pioneer. In fact, Moore also published an edited (and sadly neglected) version of his book for a popular audience, and Gribbin’s book is pitched more at this level. The new biography offers little new historical material, but Gribbin’s lucid style makes for an excellent introduction to this intriguing scientist and, indeed, to the world of quantum physics.
Gribbin sets the stage with a brief introduction to classical physics, followed by a description of the first quantum revolution. The work of Planck, Einstein and Bohr is described accurately yet succinctly in the author’s characteristic clear prose. The story continues with a description of the second quantum revolution, from Louis de Broglie’s hypothesis of wave–particle duality to Schrödinger’s brilliant wave mechanics (with Heisenberg’s matrix mechanics along the way). This is a familiar story for physicists, but one we never tire of reading.
The debate concerning the philosophical implications of the new theory is explained carefully, with a clear description of what became known as the “Copenhagen” interpretation. Einstein’s distrust of this interpretation is well known, but it is often forgotten that Schrödinger shared his views. As Gribbin points out, it is interesting that the father of wave mechanics had no faith in the idea of a wavefunction that collapses on observation, as posited by the Copenhagen camp. This objection is best exemplified by Schrödinger’s famous thought experiment of a cat that is neither dead nor alive before observation. Gribbin has written on Schrödinger’s interpretation of the quantum wavefunction many times before, notably in In Search of Schrödinger’s Cat (Bantam 1984) and Schrödinger’s Kittens and the Search for Reality (Phoenix 1996). Still, the wavefunction pioneer’s objection to the Copenhagen interpretation is worth restating.
The fascinating story of Schrödinger’s life and career is skilfully interspersed with the science. This is no easy task, given that he spent chunks of his career in Vienna, Jena, Zurich, Berlin, Oxford, Graz and Dublin, but Gribbin manages to maintain the reader’s interest throughout these sojourns without sacrificing accuracy. A good example is Gribbin’s description of the infamous Graz episode, when – having unwisely returned to Austria from Oxford in 1936 – Schrödinger penned a cringeworthy letter of apology to the Nazis, who had come to power in Austria following the Anschluss with Germany. As Gribbin explains, the publication of this letter damaged Schrödinger’s reputation abroad, while doing little to allay the Nazis’ suspicions of him.
Einstein’s distrust of the Copenhagen interpretation is well known, but it is often forgotten that Schrödinger shared his views
Into this crisis came a life-saving offer from neutral Ireland. Impressed by the Institute of Advanced Studies in Princeton, the Irish premier Éamon de Valera had decided to set up a similar institute in Dublin, with Schrödinger at the helm. The peripatetic professor accepted with alacrity and with the help of De Valera, he arrived safely in Dublin in October 1939.
He and his ménage, that is. Schrödinger set up house in Dublin with his wife Anna, his mistress Hilde and Ruth, his daughter by Hilde. As Gribbin points out, this arrangement was quite unusual in holy Catholic Ireland, yet it is a curious fact that the Schrödingers felt much more at home in Ireland than they had in Oxford. Gribbin offers the explanation that in Ireland “there was a marked contrast between what was officially approved and what people actually did”, which I think is about right. In any event, Schrödinger indulged in numerous romantic affairs in Dublin without sanction, producing two further children out of wedlock.
The description of Schrödinger’s years in Dublin is the most enjoyable part of Gribbin’s story and there are many moments of humour. For example, Gribbin describes how, in its early years, the Dublin Institute for Advanced Studies attracted the attention of the Irish Times satirist Myles na Gopaleen, who caused a stir when he observed that “Professor Schrödinger has been proving lately that you cannot establish a first cause. The first fruit of the institute, therefore, has been to show that there is no God.” The institute’s authorities were furious; Schrödinger himself was unperturbed. At the same time, Gribbin is careful not to underestimate the work Schrödinger did in Dublin, from his research in general relativity to his attempts at a unified field theory, from his work on the interpretation of quantum theory to his speculations in molecular biology.
The fact that the Dublin institute became a leading centre for the study of relativity forms an important part of Schrödinger’s legacy, but it is his work on molecular biology that is surely the most extraordinary aspect of his career. In 1943 Schrödinger gave a series of public lectures in Dublin in which he asked how hereditary information might be encoded in living cells. While much of the work he spoke about was not original, a book based on the lectures –- called What is Life? – went on to be a major influence in the field of genetics.
In the last chapter of the book, Gribbin considers Schrödinger’s interpretation of quantum theory from a modern perspective. He reviews several important developments of the past half-century, from the theoretical work of David Bohm and John Bell to the experiments of Alain Aspect and Anton Zeilinger. He then introduces the “many-worlds” interpretation and draws an intriguing connection between it and Schrödinger’s philosophy. There is an interesting point here, but the discussion is coloured by Gribbin’s own dislike of the Copenhagen interpretation.
This is a lucid biography of a brilliant scientist whose life and philosophy continues to intrigue. Although it contains little new historical material (apart from some lovely photographs and a nice surprise in the epilogue), Erwin Schrödinger and the Quantum Revolution is a cracking good read that will be enjoyed by physicists and non-physicists alike.