He was born in Vienna in 1887 to an Austrian father and a half-English mother, and grew up bilingual in German and English. At Vienna University he studied experimental, rather than theoretical, physics, and throughout his career he never lost sight of the experimental underpinning of theory. He received his degree, a not especially brilliant one, in September 1914, and was called up to the army shortly afterwards and sent to the Italian front, and later to Hungary. He was a courageous soldier, and was cited for outstanding service commanding a gun battery.

He continued his scientific studies even in the midst of the carnage of the Great War, and submitted a number of theoretical papers virtually from the trenches. Returning to Vienna in 1917 he began work on quantum theory, and made important contributions in this area of physics, which was controversial then and is so even today, although quantum mechanics is at the heart of modern technology - it may be baffling, but it works.

In 1920 Schrödinger’s alma mater offered him an assistant professorship, but by then he was engaged to marry Anny Bertel, whose job as a secretary brought her a monthly salary which was more than the annual income of an assistant professor. Schrödinger left Vienna with his new bride and over the following 18 months worked at a number of European institutions. In 1921 he accepted the chair of theoretical physics at Zurich, where he was to do his finest work.

One of the most puzzling of the many puzzles facing the quantum physicist is that atomic phenomena display simultaneously the characteristics both of particles and waves, a logical impossibility and yet a fact that has been proved not only mathematically but experimentally. Werner Heisenberg, formulator of the famous, or infamous, “uncertainty principle”, which seems to implicate the experimenter in the results of the experiment, had devised the matrix version of quantum mechanics. Late in 1925 Schrödinger generated a wave equation which ushered in the second formulation of quantum mechanics. For this achievement, described by Planck, the father of quantum theory, as “epoch-making”, and by Einstein as springing from “true genius”, Schrödinger was awarded the 1933 Nobel Prize, along with the English mathematical physicist, Paul Dirac.

Reality, as Prof Lewis Wolpert never tires of telling us, rarely accords with common sense, and this is especially true of quantum mechanics. To illustrate how differently the world works at the microscopic and the macroscopic level, Schrödinger devised an elegant thought-experiment. A cat is placed in a sealed chamber in which there is a tiny amount of radioactive material, an atom of which, over a specified period, may or may not decay, with equal probability. If it decays, it will activate a hammer which will shatter a phial of hydrocyanic acid and the cat will die. Since the probabilities are equal, the cat, according to quantum mechanics, will be both alive and dead while the experiment is in progress.

In the macrosphere, where we live, the indeterminacy is resolved when an observer opens the box and finds the cat either dead or alive. The problem is, a superposition of states - cat both dead and alive - is commonplace at the quantum level, where observation will show a single particle occupying different positions at the same time, but at what point on the scale between the quantum world and our world do quantum effects cease and commonsense, Newtonian laws take over? Schrödinger, it should be observed, devised the experiment at least partly to show the difficulties of Heisenberg’s indeterminacy principle.

Schrödinger was far from being a walking brain, as his dealings with women showed. He and his wife, Anny, had an open marriage, although while he consorted with many a mädchen she contented herself with a single lover, physicist Hermann Weyl, a close associate of her husband’s at Zurich. Later, in 1933, when Schrödinger, deploring the National Socialists and wishing to leave the German-speaking lands, expressed interest in a post at Oxford, he requested that another colleague, Arthur March, be offered a position as his assistant. This was both less and more than a philanthropic gesture: Schrödinger was conducting a passionate affair with March’s wife, Hilde, who was to bear him a child. Their attempts to observe the proprieties may have worked in Europe, but it probably prevented Schrödinger from procuring a lucrative post at Princeton, where ménages-à-trois were unacceptable.

Oddly, where Princeton was narrow-minded, Ireland, of all places, proved accommodating. In August 1938 Schrödinger was dismissed from his post at the University of Graz for “political unreliability”, despite having written a grovelling letter meant for the eyes of the Nazi authorities, saying he had “misjudged up to the last the true will and the true destiny of my country”. Eamon de Valera, a keen amateur mathematician, promptly invited him to come to Ireland to work at the Institute of Advanced Studies, which he was about to set up. After a delay of a year Schrödinger, along with his wife, mistress and mistress’s daughter, arrived in Dublin. The four settled in a modest house on Kincora Road in Clontarf, where they remained until 1956, when Schrödinger retired from the institute and returned to Vienna.

NEIL BELTON, AUTHOR of The Good Listener, a biography of Helen Bamber, founder of the Medical Foundation for the Care of Victims of Torture (which won an Irish Times literary prize in 1999), has taken Schrödinger’s story and woven it into a dense, subtle and, perhaps surprisingly, entertaining novel of ideas. A Game with Sharpened Knives - the title is Schrödinger’s own description of science, “a game with reality, a game with sharpened knives” - is set during the opening years of the war, or the Emergency, as it was called here, with typical Irish obliquity. The ménage in Kincora Road is disintegrating, with both wife and mistress sinking into bitterness and depression, and Schrödinger on the lookout for a new love to distract him from a ghastly home life and the increasingly clear fact that as a scientist his best work is behind him.

He settles on Sinéad, a spirited young woman who works as a typist in the Department of Justice, and who writes polemical journalism under a pseudonym, which is published by Schrödinger’s friend, the disenchanted literary gadfly, Quinn, in his little magazine. The plot, such as it is - Belton is a good writer, but his skills as a novelist are limited - hinges on a secret departmental document outlining the government’s plans to hand over Irish Jews in the event of a German invasion, which Sinéad copies and shows to Quinn. Various shady characters flit through the pages, including Erich Goltz, the real-life German spy who operated in Dublin in the early 1940s. In fact, early on in the novel Schrödinger, by an improbable coincidence, witnesses Goltz’s arrival in Ireland, when he spots him wading out of the waves on the Bull Island, where he has been dropped by submarine one foggy winter evening.

Belton paints a strong and persuasive portrait of Schrödinger, a man stranded in an alien environment, trying to juggle mind-numbing work with an impossible domestic life and the demands of a young mistress - Sinéad eventually bears his child; in fact, the real Schrödinger had two children with two separate Irish women - while labouring to interpret the wishes and intentions of his patron, the enigmatic and chilly de Valera. It would have been easy to draw portentously symbolic links between Schrödinger’s life and work, portraying the wife and mistress as a macroscopic version of microscopic indeterminacy, for instance, but Belton displays an admirable restraint, contenting himself with mentions of an old Dublin custom of burying a cat alive in the walls of a building for luck, and having a character point out that “Irish could be the ideal language for quantum theory. You have to live with its uncertainties”. There are flashes of quiet wit, too, as when Schrödinger passes a wagon painted with the legend: “You know you can rely on the Swastika Laundry.”

Despite the fascination of its subject and the skill with which it is fashioned, the book does not fully succeed as a novel. Belton might have been better advised to write Schrödinger’s story as non-fiction, although that way he would probably have lost a great deal of the genuine excitement he manages to generate. The narrative flashes into life in many of its setpieces, especially a confrontation in the tea lounge of the Shelbourne Hotel between Schrödinger and Goltz the spy, who is a truly frightening creation, and in the hallucinatory conversations the protagonist conducts with the visionary and perhaps even slightly mad de Valera. The portrait of Sinéad, too, is convincing, and the account of Schrödinger’s affair with her is handled with tenderness and sympathy.

The book is also, incidentally, as it were, a vividly dispiriting account of Ireland in the war years. The Irish, in Belton’s version of us, do not make for a pretty picture, although his is probably an accurate portrayal of a people still suffering from the wounds inflicted by rebellion followed by internecine warfare, and fearful of being overrun yet again by a foreign invader. In the face of international catastrophe and collapse, quiet cunning is the order of the day. As Sinéad bitterly observes: “The first language of this country is supposed to be Irish, but it’s not. It’s silence.”

[John Banville’s novel, The Sea, has just been published by Picador. A Game with Sharpened Knives, by Neil Belton Weidenfeld & Nicolson, 328pp. £10.99]