Daniel Shanks (1917-1996)

Daniel Shanks was born on January 17, 1917, in the city of Chicago, where he was raised and where in 1937 he received his B.S. in physics from the University of Chicago. In 1940 he worked as a physicist at the Aberdeen Proving Grounds, moving the following year to the position of physicist at the Naval Ordinance Laboratory, a position he retained until 1950. In 1951 his post at the NOL changed to that of mathematician, and during the years from 1951 to 1957 he headed the Numerical Analysis Section and then the Applied Mathematics Laboratory. He left the NOL in 1957 to become consultant and senior research scientist in the Computation and Mathematics Department at the Naval Ship R&D Center at the David Taylor Model Basin. In 1976 after support for independent work had considerably diminished, he decided to retire, spending a year as a guest worker at the National Bureau of Standards. He joined the Department of Mathematics at the University of Maryland as an adjunct professor in 1977 and remained there until his death on September 6, 1996. He is survived by two sisters; his sons, Leonard and Oliver; an adopted son, Gabriel; and two grandchildren. Dan (he insisted that everyone call him Dan) received his Ph.D. from the University of Maryland in 1954, but it was as early as 1949, before having done any graduate work, that he presented his thesis to the somewhat surprised Department of Mathematics. It was at this point that he requested a Ph.D. in mathematics should the work be judged of sufficient quality. There was no question concerning the excellence of the work—indeed, the final thesis was little different from the original submission—but the University (as all universities will) insisted that he complete all their degree requirements before being awarded the degree. At the time Dan was raising a young family and working full time, so it was not until 1954 that he obtained his degree. His thesis was published in 1955 in the Journal of Mathematics and Physics and was entitled “Nonlinear Transformations of Divergent and Slowly Convergent Sequences”. It concerned methods of accelerating the convergence of slowly convergent sequences and is now considered a classic in its field. The transformation that he introduced is today referred to as the Shanks transformation. Dan considered this paper to be one of his two most important published works.