Peter Robert Wilson (1929–2007)

It is with great sadness that I report the passing of Peter Robert Wilson, a well-known and well-loved figure in the solar physics community. Peter was on the faculty of the Department of Applied Mathematics at the University of Sydney for 39 years, and Chair of the department for 24 of these years. He was the author or co-author of more than 80 scientific research papers and a book, Solar and Stellar Activity Cycles (1994), published by Cambridge University Press. He died suddenly of a heart attack, at his home in Glebe, Australia, in the early morning of 11 November 2007.

Peter was an organizer of, and participant in, many international conferences and workshops. He traveled extensively, holding visiting appointments at the University of Colorado (JILA), at Cambridge University, at the College de France (Paris), and at the California Institute of Technology [CalTech]. Most of his work was in the field of solar physics, but he also did some work on the philosophy of science and on tides.

Peter came from a line of mathematicians. His father, Robert Wilson, immigrated to Australia from Glasgow in 1911, and became a mathematics teacher at Scotch College, a private school in Melbourne. There his name was changed to 'Bill' because 'Bob' was already taken."

Peter's enjoyment of this story as characteristic of Australian academia (as any fan of Monty Python would understand) is indicative of his infectious sense of humor. In a similar vein, he claimed ancestry traced back to the eighteenth-century Scottish mathematician Alexander Wilson, Professor of Astronomy at the University of Glasgow. That Wilson is famous in the solar physics community for his discovery, known as the "Wilson Effect," of the photospheric depressions associated with sunspots. Peter himself could not resist writing a paper on this subject, and was delighted when the bait was taken by some less-informed colleagues who chided him for "naming an effect after himself."

"Bill" Wilson married Naomi Christian, a Melbourne native, and together they had three children. Peter was the eldest; he was born on 17 October 1929. He attended Scotch College, where his father taught, and went on to the University of Melbourne where he eventually earned an M. Sc. in experimental physics. This was not his cup of tea, however, and he first endeavored to follow in his father's footsteps, taking short-term appointments teaching mathematics at the secondary-school level abroad, in England, and in Scotland. After a few years Peter returned to Melbourne and took a post at Scotch College following his father's retirement. He soon decided, however, that teaching young boys in a private school was not his cup of tea either, and in 1959 he secured a position in applied mathematics at the University of Sydney. He had just married his first wife, Margaret, and they moved north together to start their family.

Peter flourished at the University of Sydney, but his advancement in rank was hampered by the lack of a Ph. D. The problem was solved by Ron Giovanelli, Chief of the Division of Physics at Australia's Commonwealth Scientific and Industrial Research Organization [CSIRO], an astrophysicist whose interest lay in the transfer of radiation through the outer layers in the Sun. Giovanelli took Peter on as a thesis student. This both earned him the needed Ph. D. and started him on his research career in solar physics. He now began to move up the academic ladder at Sydney.

To satisfy his love of adventure, Peter was also able to take a series of visiting positions in the United States, working with Dick Thomas and others at JILA and Sacramento Peak Observatory (National Solar Observatory) in New Mexico. During this time he created a framework for further collaborations that became known as the Sydney-Boulder Astrophysics Association [SBAA].

In 1971 Peter was appointed Professor and Chair of the Department of Applied Mathematics at Sydney, and for the next two decades he worked hard to strengthen this department. He was very successful in this endeavor; he had a reputation for fairness and honesty and was well liked. Under his leadership the department grew in both size and quality. Peter fostered a group of outstanding students, including Chris Cannon, David Rees, and Lawrence Cram. One of his proudest accomplishments was to recruit several women onto the faculty and to increase the number of female students. One of these, Nalini Joshi, is presently Head of School. After Peter resigned as Chair, he went on to several other positions associated with the governance of the University, including the Academic Senate, the Governing Council of the Women's College, and the Board of Trustees.

Peter and his first wife were divorced in 1982, after their two children, Sally and Michael, had grown up and left home. A few years later he met and married Geraldine Barnes, a Senior Lecturer in the English Department. This proved to be a fabulous match; they supported each other's academic pursuits, attended each other's conferences, enjoyed a rich social life centered around the university, and traveled extensively together. Their marriage helped both of them refocus their careers. Geraldine steadily advanced in rank, and is now Head of the School of Letters, Arts and the Media. Peter became one of the chief organizers of a series of workshops focused on the solar activity cycle.

The first solar cycle workshop was held in 1986 at CalTech's Big Bear Solar Observatory [BBSO], and it was at this meeting that I first met Peter. There were three subsequent meetings, roughly a year apart, held at the University of Sydney, at Stanford's Fallen Leaf Lake in the Sierras, and at Sacramento Peak Observatory, and these were very successful in bringing together the main players in this research field. My subsequent association with Peter involved several trips back and forth between Portland (Oregon), Boulder, and Sydney and collaborations on about a dozen controversial research papers. Together with Peter Fox and Pat McIntosh, we became the solar-physics "gang of four."

A dinner in Sydney with Geraldine, Peter, and their friends always meant liberal amounts of fine Australian wine, lively conversations on every imaginable topic (except physics), much laughter, and a deliciously endless meal. A weekend at their beach house in Killcare was even better, featuring long walks on the golden-sand beach and in the nearby bush. Kookaburras, Currawongs, and Rainbow Lorikeets frequented the outdoor deck, and the bush teemed with large and fascinating spiders. Back in Sydney, short-term visitors enjoyed lodgings and excellent breakfasts at the University of Sydney's Women's College, with Peter on the Council.

Peter was a man of many interests. He was an expert sailor, a small-plane pilot who took colleagues and friends on adventurous flights, and a lover of sports. He was a skier, a hiker, and a good tennis player who disdained proper form but usually won the point. In 1994, one day after his 65th birthday, Peter suffered a serious stroke. Recovery from this was extremely difficult, painful, and slow; he did, however, recover to a remarkable degree. He had to learn to walk all over again and his vocal chords were partially paralyzed, but after several years of determined work, Peter was able to play a little tennis and squash, and he could bowl and hike. During the last decade of his life he traveled to Easter Island, to the Galapagos, and to the Ross Ice Shelf in Antarctica.

Peter continued to take pleasure in his research to the end, in collaboration with close colleagues who were always among his closest friends. Among these was Chris Durrant, who had been Head of the School of Mathematics and Statistics from 1994 to 1998. They were writing a series of papers on the mechanism of the Sun's polar field reversals. I was looking forward to joining them this coming summer. My last visit with Peter was in Phoenix, Arizona, where Geraldine was participating in a conference. We hiked into the Superstition Mountains, and I remember him walking slowly, being careful of his balance, but going the whole distance with pride and in good spirits.

Peter was a truly remarkable man with, as Geraldine has put it, "a genuine gift for leadership and the encouragement of team spirit." He was a creative and productive scientist with a tremendous life force, a great sense of adventure, and a warm heart. My own collaborations with him were a joy. His death is a sad loss to all who knew him, and he will be sorely missed, but Peter R. Wilson lived life to the fullest and gave his best to the world. We should be glad for him. At the end of his (unpublished) autobiography, where he describes his recovery from the stroke, he writes:

"So as I forecast in 1994, I have continued to 'soldier on', and must admit that a miracle has indeed occurred, at least 80%; I wouldn't have missed the past ten years for anything. Who knows what the inevitable advance of old age may hold, but I cannot complain that I have been 'short changed' in any way."