John H. Reynolds, Physics: Berkeley
John Reynolds--man of many parts, but foremost a physicist--died of complications from pneumonia in Berkeley on November 4, 2000. He was born in Cambridge, MA, on April 3, 1923. His mother and father were persons of letters, educated at Wellesley and Harvard. His father taught English at various colleges and John wrote that he was “undoubtedly predisposed towards the academic life by this home environment.” At school and college, he “enjoyed tinkering with electricity and radio and studied piano and harmony.” He achieved a Harvard A.B. degree summa cum laude in 1943 and then served as a Navy ordnance specialist on island bases in the South Pacific. On return from the Navy, his interest was “captured by the Chicago physics group on reading about the Manhattan project.” At Chicago, where he specialized in experimental mass spectroscopy, he was strongly affected by the nascent geochemistry and cosmochemistry developments there and by his Ph.D. thesis advisor, Mark Inghram, and by Harold Urey and Enrico Fermi. He attended two year-long courses by Fermi, “enrolled in neither but never missed a lecture.” This influence was felt in John's choices of applications of mass spectroscopy to problems ranging from the search for a hypothetical radioactive decay mode called “double beta decay,” to the age of the elements in the solar system, and later to key problems on the origin of man, the evolution of the continents and the history of the Moon. Eventually, the modern sciences of geochronology and nuclear cosmochronology grew in large part out of the work of Reynolds and his students.
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He was appointed to the Physics Department at Berkeley in 1950. Conditions at Berkeley were then such that interaction with geology and geophysics flourished from the beginning. Indeed, his selection by Francis A. (“Pan”) Jenkins during a recruiting trip to Chicago was influenced by previous suggestions by Francis Turner and John Verhoogen of the Geology Department that a physicist skilled in isotope spectroscopy would be “a useful adjunct.” As a new Assistant Professor he designed and built the first static (non-pumped) all-glass mass spectrometer for isotope analysis of the noble gases. For many years he kept his laboratory in the forefront, usually ahead of his competitors. He became known as the “father” of extinct radioactivities and, in geophysics, for his seminal contribution to plate tectonics. He was the first to detect isotopic anomalies, the study of which culminated in overwhelming evidence for preservation in the meteorites of pre-solar grains (sometimes called “stardust”). In 1960, for example, he detected the xenon isotope of mass 129 trapped in meteorites, and from that discovery inferred that the extinct radioactive isotope iodine-129 (half-life 16 million years and probably generated in a pre-solar system supernova or supernovae) was present when the meteorites formed. This indicated that the meteorites appeared in the early history of the solar system; in later studies he and collaborators showed that other short-lived species were present in the cloud of gas that turned into our solar system 4.6 billion years ago. He summarized these findings in his 1973 Faculty Research Lecture “Telling the Aeons of Forgotten Time.” Key improvements at his laboratory in the potassium-argon dating method, including invention there of the sensitive 39Ar--40Ar technique, led to seminal advances in earth science by his students and others he influenced, most notably the development of the paleomagnetic time-scale and the proof derived from it of seafloor spreading. By 1955, John Reynolds and his collaborators, Joseph Lipson and others, had the capability at Berkeley of applying the potassium-argon dating method to more difficult researches than hitherto. To name a few notable applications, in the Geology and Geophysics department, Professors Garniss Curtis and Jack Evernden dated crucial series of young rocks, thus opening the door for a quantitative geological time-scale and plate tectonics. (The history of John Reynolds's contributions, based partly on
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personal interviews, is set down in The Road to Jaramillo, William Glen, Stanford, 1982.) Of archeological importance, the volcanic ash layers at Olduvai Gorge were dated using the Reynolds spectrometer, enabling Professor Richard Hay to fix closely the fossil sequence of man's pre-history. As a consequence of these successes, Reynolds's potassium-argon methodology was adopted by new geochronology laboratories at the Australian National University, the U.S. Geological Survey, at the University of São Paulo, Brazil and at Coimbra, Portugal. While at São Paulo on Sabbatical leave John Reynolds worked with Umberto Cordani and others to establish the first geochronology laboratory in South America, “one of the most interesting projects I have ever undertaken.” For the latter collaboration, John was awarded the prestigious Order Nacional do Cruzeiro do Sul with grade of Comendor in 1968 (but returned it later on a matter of principle).
For his research and teaching John Reynolds received many honors:
John pursued a wide range of interests outside of academic physics. He was an avid sailor who played an active part in the Cal Sailing Club in the 1970s. He had long dreamed of returning under sail to the South Pacific. That goal was partly fulfilled in 1989 when, as a crew member aboard a sailboat in the California to Hawaii Transpac Race, he sailed from Long Beach to Honolulu. Among fond memories from a Sabbatical leave in the Physics
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Department, Perth, University of Western Australia, colleagues remember his one-mile ocean swims each morning seaward of the reef. In later years, he cruised extensively with his wife Ann in their 30-foot sailboat, Manx. They made summer cruises to Alaska as well as a two-summer passage through the Great Lakes and New England. He had just completed his second round-trip voyage to Alaska several weeks before his untimely passing. He was also an amateur astronomer, using the UC Leuschner observatory for enjoyable evenings viewing the night sky. Another pursuit was amateur radio, an interest that led to many ethereal contacts around the world. John also was an amateur beer maker and bread baker.
He took the responsibility of service to the University seriously and served as chairman of the Physics Department in the 1980s. During this time, he made several changes that benefited the department in lasting ways and promoted a feeling of harmony and cohesiveness that was appreciated by the faculty. His tenure as chair set an example of serious, thoughtful stewardship as well as fair and even-handed use of resources. Many younger colleagues remember warmly his considerable generous help over the years. He was President of the Faculty Club in 1968-70 and served again on the Board 1996-2000. He much enjoyed singing at the Club with the Monks. During his final hospital stay he wanted to make sure that the Club piano had been tuned for the Christmas parties. John's societal concerns extended beyond the walls of academia. He was a staunch believer in representative democracy and ran for the Berkeley Rent Board out of a sense of civic duty. He was also active in the League of Women Voters. John remained intellectually curious and eager for new knowledge to the last. On the morning of his passing, he called a colleague for a book he intended to read on the life of Ulysses S. Grant. He is survived by his wife, Ann Reynolds, his children, Amy, Horace, Brian, Petra, and Karen, and his sister Peggy, of Santa Fe.
Bruce A. Bolt Richard E. Packard P. Buford Price
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