Dr. Sydney Chapman (1888-1970) was Professor of Geophysics and Advisory Scientific Director of the Geophysical Institute from 1951-1970. He spent three months of each year at College -- usually the winter months when the aurora was overhead, and he also preferred walking in the snow -- and a goodly part of the remainder of the year at the High Altitude Observatory of the National Center for Atmospheric Research in Boulder, Colorado. But where Sydney Chapman might be at any given time involved an uncertainty principle of the Heisenberg kind, evidenced only by the postage stamps on the meticulously written letters that arrived from London, Cambridge, Moscow, New Delhi, Sydney, Tokyo, Ann Arbor, Minneapolis, Mexico or Ibadan. His influence upon the Geophysical Institute was immense. The Honorary Degree of Doctor of Science was conferred on him by the University of Alaska in 1958 and the old home of the Institute was named for him in 1968 . (For 'Chapman Day' on campus, commemorating his 80th birthday, see the Annual Report for 1967-68.) Dr. Chapman died at Boulder, Colorado, on June 16,1970, at the age of 82. He is survived by his sons Cecil, Robert and Richard and by a daughter, Mary. His wife, Katharine died in 1967.
Sydney Chapman was born at Eccles, Lancashire, in England on January 29, 1888. He attended the University of Manchester (B.Sc. in engineering 1907, M.Sc in physics in 1908, D.Sc. 1912) and the University of Cambridge (BA in mathematics 1911, M.A. 1914). He was Chief Assistant at the Royal Observatory, Greenwich; lecturer in mathematics at Trinity College, Cambridge; Professor of Mathematics and Natural Philosophy at the University of Manchester, Chief Professor of Mathematics at the Imperial College of Science and Technology, and Sedleian Professor of Natural Philosophy at the University of Oxford. Subsequently he became associated with many institutions, either as visiting professor or on a continuing part-year basis, among them the University of Alaska, the University of Michigan, New York University, the University of Istanbul, the State University of Iowa, the High Altitude Observatory at Boulder, the Gottingen Academy in Germany, Ibadan University and the University of Mexico. A Fellow of the Royal Society of London and a foreign member of the National Academy of Sciences of the USA, he was honored by many countries and scientific bodies with medals, prizes, honorary memberships and honorary degrees. He contributed assiduously to the organizational and social aspects of science, having been president of seven professional societies (the London Mathematical Society, the Royal Astronomical Society, etc.) and international president of the I.G.Y. He and the late Lloyd Berkner have been called the 'fathers of the IGY'.
What Professor Chapman contributed to mathematics and science of geophysics---inadequately cataloged by a mere listing of his more than 450 papers---is well narrated in the book compiled by his colleagues and former students and presented to him on his 80th birthday (Sydney Chapman, Eighty---from his friends, edited by S.-I. Akasofu, B. Fogle and B. Haurwitz, sponsored by the University of Alaska, the University of Colorado and the University Corporation for Atmospheric Research). As Walter Orr Roberts remarks in the Testimonial of that book, "Graduate students entering astro-geophysics today, challenged by his astonishing command of the tools of their trade, fine it hard to believe that this is the same Sydney Chapman who, nearly five decades ago published his great works on the kinetic theory of gases". In 1939, Chapman, with T.G. Cowling, published the classic volume The Mathematical Theory of Non-Uniform Gases. It was followed in 1940 by the monumental two-volume work Geomagnetism (co-authored with the late J. Bartels). A much simplified and abridged account of the geomagnetism had been published as a Methuen monograph in 1936, The Earth's Magnetism. His popularly written book on the International Geophysical Year, The IGY, Year of Discovery, won the Thomas Alva Edison Foundation Award in 1959 for the best science book for youth. In applied mathematics, the kinetic theory of gases, astronomy and geophysics the name of Chapman has been a standard reference for generations of students and researchers. He has a permanence in the literature. And because he was a master of the English language as well as the subject matter, his expositions, either written or verbal, always possessed an unexceptionable precision---for whatever level of audience he addressed himself.
On a more personal note, an attribute which often impressed me was Sydney Chapman's memory for detail---dates, places, faces, names, references, etc.---which, even with advancing age, seemed rarely to fail him (even such things as the price of an airline ticket from London to Cairo and what it cost in pounds sterling to make the same journey by P.&O steamer in the 1930's). One of our younger men was giving a seminar in which he described an allegedly new method for making a certain auroral measurement. Sydney listened patiently then gently remarked to the effect 'You have rediscovered in the 20th Century what was rediscovered in the 19th Century and discovered in the 18th Century', and proceeded to quote chapter and verse. His knowledge of the history of science and the origins of scientific ideas was profound and gave that scholarly edge to his lectures which is (regrettable) increasingly unfamiliar to younger scientists. The leavening awareness of the paths of emergence of what, today, we call science is one of the factors, I believe, that gave Sydney the balance and perspective noticed by all who knew him. It was often in discussion of historical points that his astonishing memory and wide reading manifested itself---and I early learned, after coming to Alaska, that to tangle with him on dates and names or the precise nature of an early accomplishment was to invite disaster! He mildly upbraided me one evening for not having read Roger Bacon's Opus Tertium, Opus Minus, Compendium Philosophiae, a 13th Century treatise, which, he pointed out, was in the Institute library. It was duly delivered to my desk the following day by the librarian at Sydney's request. My interest waned sharply, however, on finding the entire text to be in Latin, although that did not seem to have deterred Sydney.
One winter evening at my house, sitting round the fire, conversation turned to Spain (I cannot remember why, except that Sydney was interested in the San Fernando magnetic records about then) and thence drifted to the Moslem influence on Europe, to the Moslems, to Arabic science in general, and the Arabian scientist Alhazen---in the way after-dinner conversations go with coffee and cognac (though Sydney declined the latter). All this led to a friendly dispute on the origin of Snell's law of refraction and precisely what Alhazen had contributedÉ leading, as usual, the following day to a memo from me which began: Dear Sydney, I looked up Alhazen and found that you were right. It was Ptolemy of Alexandria in the 2nd Century who made the first approximationÉ" (Incidentally, Chapman regarded Alhazen's computation of the height of the atmosphere as about 10 English miles as a remarkably fine achievement for its time, the 11th Century.) He read widely in history and prehistory, in fields far remote from his own. Joseph Needham's studies on science in China were absorbed as they arrived, volume by volume, and he was equally familiar with the work of the Leakeys on ancient man in Africa. We often talked about such things on winter evenings at the house. When, as rarely happened, I was able to draw his attention to a book he had not encountered he invariably found and read it---and generally this would be the first topic the next time we yarned One which especially interested him was Casson's The Ancient Mariners, an account of ships and shipping in classical times. It led to prolonged discussion of the design of triremens and the meaning of the 'sixes', 'twelve's', 'twenties', etc. to by Greek and Roman writers---also to Sydney expressing his belief that Necho's expedition really did circumnavigate Africa in the 6th Century BC
To the University of Alaska over a span of nearly twenty years, the presence of Sydney Chapman on campus meant a scholarly culture and supreme standard that in earlier days made its pointed mark and never ceased to exert a spell upon the Institute.