Erwin Rudolf Josef Alexander Schrödinger was an Austrian theoretical physicist famous for his mathematical development of wave mechanics (1926), a form of quantum mechanics (see quantum theory) and for his formulation of the wave equation that bears his name. The Schrödinger equation is the most widely used mathematical tool of the modern quantum theory.  For this work, he shared the 1933 Nobel Prize in Physics with P. A. M. Dirac. In 1935, after extensive correspondence with personal friend Albert Einstein, he proposed the Schrödinger's cat thought experiment.

In January 1926, Schrödinger published in the Annalen der Physik the paper Quantisierung als Eigenwertproblem [tr. Quantization as an Eigenvalue Problem] on wave mechanics and what is now known as the Schrödinger equation. In this paper he gave a "derivation" of the wave equation for time independent systems, and showed that it gave the correct energy eigenvalues for the hydrogen-like atom. This paper has been universally celebrated as one of the most important achievements of the twentieth century, and created a revolution in quantum mechanics, and indeed of all physics and chemistry. A second paper was submitted just four weeks later that solved the quantum harmonic oscillator, the rigid rotor and the diatomic molecule, and gives a new derivation of the Schrödinger equation. A third paper in May showed the equivalence of his approach to that of Heisenberg and gave the treatment of the Stark effect. A fourth paper in this most remarkable series showed how to treat problems in which the system changes with time, as in scattering problems. These papers were the central achievement of his career and were at once recognized as having great significance by the physics community.

In 1927 Schrödinger moved to Berlin as Planck's successor when he retired from the University of Berlin. He left Germany in 1933 due to his dislike with the rise of Nazism. He went to Oxford University for three years, and then returned to a university post in Austria. But in 1938, Germany invaded and Schrödinger was dismissed. The Prime Minister of Ireland at the time, Eamon de Valera, was a mathematician and invited Schrödinger to join the newly established Institute for Advanced Studies in Dublin. Schrödinger emigrated there with few possessions and little money. He remained for 17 years, often turning his attention to philosophical questions about physics and its relationship to other fields.

Schrödinger's book What is Life? (1945)  inspired many subsequent efforts to explain biological evolution, especially the evolution of complex systems, in terms of the Second Law of Thermodynamics and the concepts of "entropy" and "negative entropy." According to James D. Watson's memoir, DNA, The Secret of Life, Schrödinger's book gave Watson the inspiration to research the gene, which led to the discovery of the DNA double helix structure. Similarly, Francis Crick, in his autobiographical book What Mad Pursuit, described how he was influenced by Schrödinger's speculations about how genetic information might be stored in molecules.

Sources

• Nobel Foundation, Erwin Schrödinger, The Nobel Prize in Physics 1933, Nobel Lectures, Physics 1922-1941, Elsevier Publishing Company, Amsterdam, 1965.
• O'Connor, John and Edmund F. Robertson, Erwin Rudolf Josef Alexander Schrödinger, MacTutor History of Mathematics Archive, School of Mathematics and Statistics, University of St Andrews, Scotland, Accessed 30 December 2008.
• PBS.org, Erwin Schrödinger, Accessed 30 December 2008.
• Wikipedia Contributors, Erwin Schrödinger, Wikipedia The Free Encyclopedia, Accessed 30 December 2008.