##### Based on the obituary by Robert Adler, published in the Bulletin of the IMS, January 2006 (*adapted by Krzysztof Burdzy*)

Ronald (Ron) Pyke was associated with the Department of Mathematics at the University of Washington from 1953 to 2005, except for a few short periods. He was first a graduate student, then a member of the faculty, and finally a Professor Emeritus.

Ron Pyke passed away on October 22, 2005, as a consequence of amyotrophic lateral sclerosis. He was 73. Ron was born on November 24, 1931, in Hamilton, Ontario, and graduated from Westdale High School in Hamilton in 1949. He married Gladys Mary Davey on December 19, 1953, in Hamilton.

Ron graduated with honors from McMaster University in 1953 and then moved to the University of Washington. He completed an MSc in Mathematical Statistics in 1955 and a PhD in Mathematics in 1956 under Bill Birnbaum on the topic "On one-sided distribution free statistics."

Immediately following his PhD, Ron moved to Stanford for two years, followed by another two at Columbia. In 1960 he returned to Seattle, where, except for sabbaticals at Cambridge (64/65), Imperial College (70/71) and the Technion (88), he settled permanently. Ron retired from the University of Washington in 1998.

In his early professional years, Ron made a number of important contributions to topics as diverse as statistical hypothesis testing (mainly centering around Kolmogorov-Smirnov and other goodness of fit statistics), Markov renewal and branching processes, empirical processes, fluctuation theory and two-armed bandits, to give but an abbreviated list. A significant majority of the papers were published in the Annals of Mathematical Statistics, and even briefly running through his early papers one sees any Search Committee's dream candidate in terms of their breadth and quality.

When Ron first arrived at the University of Washington there was no independent Statistics department, and activity in Statistics was concentrated in Mathematics. In 1965 a 'Biomathematics Group' interdisciplinary program was set up, in which Ron was heavily involved. Ron also worked tirelessly towards the establishment of an independent Department of Statistics, which was finally established in 1979, and is now one of the leading departments in the US, with over 25 faculty members. Although Ron originally joined the infant department, he shortly thereafter returned to Mathematics.

In 1973 Ron published his first paper on the Brownian sheet (also coining the name that then stuck to this remarkable process). While Ron's interest in the Brownian sheet grew out of his work on Kolmogorov-Smirnov type statistics, from the 1970's onwards he was concerned more with its amazing local sample path properties. Retirement did not stop Ron from working, and his last paper, written with long-time friend and colleague Willem van Zwet, appeared in the Annals of Probability in 2004.

Over the years Ron supervised 15 PhD students, many of whom are now well known names in statistics and probability.

Ron began what was to be a lifelong commitment to the Institute of Mathematical Statistics by taking an active leadership role. In 1963, at the age of 32, Ron chaired his first Institute of Mathematical Statistics committee, the Program Committee. In the Institute of Mathematical Statistics, Ron was probably best known as a previous President (1986/7) and as the editor of the fledgling Annals of Probability in the first four years of its existence, from 1972 to 1975.

As one would expect from a scholar of his calibre, Ron was a Fellow of the American Statistical Association and Institute of Mathematical Statistics, an Elected Member of the International Statistical Institute, and had a long list of invited addresses and other honors. He served as the Institute of Mathematical Statistics President in 1986/7, and also as International Statistical Institute Vice President from 1989 to 1991.