Saul Abarbanel

Oral History (pdf)

**Interviewer:** Philip J. Davis

Saul Abarbanel describes his work in numerical analysis, his use of early computers, and his work with a variety of colleagues in applied mathematics. Abarbanel was born and did his early schooling in Tel Aviv, Israel, and in high school developed an interest in mathematics. After serving in the Israeli army, he entered MIT in 1950 as an as an engineering major. He found himself increasing drawn to applied mathematics, however, and by the time he began work on his Ph.D. at MIT he had switched from aeronautics to applied mathematics under the tutelage of Norman Levinson. Abarbanel recalls the frustration of dropping the punch cards for his program for the IBM 1604 that MIT was using in 1958 when he was working on his dissertation, but also notes that this work convinced him of the importance of computers. Three years after receiving his Ph.D., he returned to Israel, where he spent the rest of his career at Tel Aviv University. He used the WEIZAC computer at the Weizmann Institute, and in the late 1960s worked on a CDC machine and an early transistorized Philco computer owned by the Israeli Army. Although Arbarbanel’s early work was more computational, his later work reflects his mid-career realization of the importance of theory in achieving practical results. He enjoyed his time at NASA’s Institute of Computer Applications to Science and Engineering (ICASE), which he believes served an important role by bringing together outstanding scientists and mathematicians and allowing them an opportunity to become better acquainted and to collaborate more extensively. Besides his extensive collaboration with David Gottlieb, Abarbanel worked with a variety of colleagues during his career, including engineers Earl Murman and Ajay Kumar. He discusses well- and ill-posed equations, and distinguishes ill posedness and instability from chaos. He believes that his training in engineering and aerodynamics gave him an advantage in doing applied mathematics. He thinks that today’s students in numerical analysis can benefit from exposure to the sciences and should receive training in a broad range of mathematical tools. He thinks that his work with David Gottlieb demonstrating that linearized Navier-Stokes equations can be symmetrized and highlighting problems of boundary conditions for infinite fields in electromagnetics as among his most significant contributions.

**Key words:** aeronautics, IBM 1604, WEIZAC, ill-posed problems, instability, Navier-Stokes equations, boundary conditions in electromagnetics

**Funding Agency:** NASA

**Time frame:** 1950's, 1960's, 1970's

**People:** Norman Levinson, Norbert Weiner, David Gottlieb

**Location:** Massachusetts Institute of Technology, Tel Aviv University, Weizmann Institute, ICASE

**Citation: **Saul Abarbanel, Oral history interview by Philip Davis, 29 July, 2005, Brown University, Providence, RI. Society for Industrial and Applied Mathematics, Philadelphia, PA

**Statement of Use Policy**: Copyright © by the Computer History Museum. Use of this the material for research purposes is allowed. Any such use should cite the SIAM History of Numerical Analysis and Scientific Computing Project (http://history.siam.org). Use of the oral history materials for commercial purposes requires the written permission of the Computer History Museum. Contact the Computer History Museum, 1401 N Shoreline Boulevard, Mountain View, CA 94043-1311 USA for permissions.