Schrödinger: Life and Thought
by Walter Moore
Cambridge University Press, 513 pp., $39.50
The transformations in theoretical physics during the twentieth century have two main lines, each with a key term, “relativity” and “quantum theory.” Both sets of changes were responses to problems in the natural philosophy passed down from Isaac Newton to the scientists of the 1890s—the presuppositions underlying the body of theory we know, in retrospect, as “classical” physics. But the two sets of changes took place in very different ways.
The early history of relativity is dominated by a single creative thinker, Albert Einstein, and comes close to being his intellectual biography. Not that Einstein claimed to solve his own problems single-handed. He was aware of his debts to forerunners who had helped to clarify those problems, and to contemporaries who worked alongside him. But his imagination was so remarkable and the originality and power of his arguments carried such conviction that they did much to shape the general approach to solving these problems. By contrast, the early history of quantum physics has involved so large a cast of characters that even a cursory account must cover two dozen original physicists with different views and backgrounds: Max Planck, Niels Bohr, Paul Dirac, Louis de Broglie, Arnold Sommerfeld, Werner Heisenberg, and Erwin Schrödinger, as well as Albert Einstein himself, to list only the most eminent participants and to carry the story only up to 1939.
This difference, along with the difficulty of writing about quantum mechanics in colloquial language, explains why up to now few of the architects of quantum physics have been subjects of full biographies. There have been fine essays on Niels Bohr’s life and work; but the biography of Erwin Schrödinger (1887–1961) under review is one of the first full-scale attempts to evaluate the work of one such physicist and see him from a late-twentieth-century perspective. How did Schrödinger earn this place?
Nineteenth-century physics inherited two dichotomies from the new “mechanical philosophers” of the seventeenth century, notably René Descartes and Isaac Newton. One of them was external to physics. It set up a boundary dividing the realm of Matter, material objects and causal processes, from that of Mind, mental activities and rational thought: hence the epistemological “dualism” in which Newton fully shared. It is true that, from Hermann Helmholtz in the 1860s to Sigmund Freud, Ernst Mach, and Wilhelm Ostwald at the turn of the century, the “monists” looked for an epistemological approach that would show how physics and psychology could both be generated from a common starting point. But, even in 1900, there was still no way of putting this philosophical program on a strict scientific footing.
The other dichotomy was internal to physics. It separated physical processes of two kinds: mechanical interactions of tangible objects by contact or impact, and those phenomena—electrical, optical, magnetic, or gravitational—that were less tangible, and affected objects distant from one another. In classical physics it was taken as axiomatic that (as Newton put it) God in the Beginning made matter into “hard, massy, impenetrable, moveable particles …