John Charles Polanyi

views updated May 21 2018

John Charles Polanyi

John Charles Polanyi (born 1929) was a Canadian scientist whose work with chemical reactions led to the construction of a "chemical laser" and to a share of the 1986 Nobel Prize in Chemistry.

John Polanyi was descended from a gifted Hungarian family. His grandfather, Mihaly Pollacsek, was a successful railway builder, and his grandmother was active in the intellectual life of Budapest. From a line of assimilated Jews, Mihaly gave the family its Hungarian name, Polanyi. Among their remarkable children, Laura was an intellectual whose ideas of "rural sociology" influenced Tito. One son, Adolph, became an engineer and moved to Brazil. Another, Karl (1886-1964), was one of the century's influential critics of market capitalism. John's father, Michael, was an accomplished chemist and philosopher. When Hitler came to power, Michael moved his family from Berlin, where John was born (January 23, 1929), to England. He joined the faculty of Manchester University, where as a professor of chemistry he did pioneering work on the mechanisms of elemental reactions. He spent his later years writing books of philosophy.

During World War II Polanyi was sent to safety in Toronto, along with other children who were "adopted" by faculty of the University of Toronto. He entered Manchester University in 1946 and received his Ph.D. in chemistry in 1952 on the basis of his work measuring the strengths of chemical bonds in compounds that have been subjected to very high temperatures. That same year he accepted a postdoctoral fellowship at the National Research Council of Canada (NRC) in Ottawa, where he worked with E.W.R. Steacie and spent a few months in the laboratory of future Nobel laureate Gerhard Herzberg. Polanyi had already directed his work to the study of the motions of newly-born reaction products and to the telltale imprints of the forces that created them. After two years at Princeton University, he returned to Canada in 1956 as a lecturer in chemistry at the University of Toronto, where he served as a university professor after 1974.

In 1958 Polanyi and his graduate student assistant, Kenneth Cashion, published their first findings on infrared chemiluminescence (the emission of light by an atom or molecule that is in an excited state). By introducing newly-formed atomic hydrogen into a stream of chlorine gas at low temperatures, they found that instead of losing their energy in collisions, the newly-formed hydrogen chloride molecules discharged it in a cascade of infrared photons. In one of those coincidences of discovery that mark the history of science, Arthur Schawlow (a graduate of the University of Toronto) and Charles H. Townes almost concurrently developed the principle of the laser, for which they shared a Nobel Prize in 1964. Polanyi was quick to realize that his findings could have important practical implications for the construction of a powerful "chemical laser." In 1964, J.V.V. Kasper and G.C. Pimentel were able to construct such a laser based on chemical reactions. Since then these "vibrational" lasers have made enormous contributions to science, medicine, and industry. Beyond this considerable practical benefit, Polanyi's discoveries provided a new way of investigating the very nature of chemical reactions themselves.

Polanyi's contributions to science were recognized on a global scale in 1986 when he shared the Nobel Prize in Chemistry with Dudley Herschenbach and Yuan T. Lee for developing "a new field of research in chemistry … in which the extremely weak infrared emission from a newly-formed molecule is measured." His later work focused on the use of spectroscopy (the science that deals with the analysis of the light spectrum) to gain an insight into what he called the "molecular dance" in chemical reactions, the process by which chemicals change partners.

Polanyi was an articulate and urbane man whose interest and influence ranged far beyond his contributions to chemical science. He was a vocal critic of short-sighted government science policies that look skeptically on the value of "pure" research because it may not have immediate practical or economic benefit. His own work is a testament to the value of fundamental research, not only in the practical development of the laser but in its contribution to a deeper human understanding of nature. He asked potential sponsors if they could have foreseen that his obscure work on "infrared luminescence" would lead to the development of lasers.

Polanyi was active in the peace and disarmament movements as founding chair of the Canadian Pugwash Group and as a speaker and prolific author. In 1996 he forcefully argued that war-torn Bosnia would only have a future if western peace keepers remained. He also spoke widely on the nature of science and its relation to creativity, art, and as a force for positive change in society. In a 1994 speech at University of California at Berkeley, he emphasized the responsibility scientists have to forging peace and solving world problems: "Science is an enterprise that can only flourish if it puts the truth ahead of nationality, ethnicity, class and color." He received numerous honors in addition to the Nobel Prize, including Canada's highest civilian honor, Companion of the Order of Canada (1979). He was co-winner of the Wolf Prize in 1982, received the Izaak Walton Killam Memorial Prize (1988), the Royal Medal of the Royal Society of London (1989), the Bakerian Prize (1994) and more than two dozen honorary doctorates from universities in six countries. In the 1990s Polanyi, still a professor of physical, polymers and materials chemistry at University of Toronto, continued his research on the photochemistry of absorbed molecules.