Julia Bowman Robinson

1919-1985

American Mathematician

Julia Robinson was a prominent mathematician who devoted her career to applying number theory methodology to the resolution of mathematical logic problems. The Julia Robinson Hypothesis led to the solution of Hilbert's Tenth Problem, which mathematicians had pondered for decades and feared was unsolvable. She also achieved scientific leadership positions previously not held by female mathematicians and used her influence to seek equal opportunities for all scholars. Considered a mentor and exemplary figure, Robinson inspired mathematicians of both genders to approach mathematical puzzles with ingenuity and resourcefulness.

Robinson was born in St. Louis, Missouri, on December 8, 1919, to Ralph Bowers and Helen (Hall) Bowman. When she was two-years old, her mother died. Robinson lived first in her grandmother's home in Phoenix, Arizona, and then in San Diego, California, when her father remarried. Suffering scarlet fever when she was nine, Robinson was quarantined. Within a year, she contracted rheumatic fever and was confined to bed. During this time, her tutor inspired her interest in mathematics. Initially, she began taking classes at San Diego State College and planned to qualify as a public school teacher, specializing in mathematics.

As she became interested in researching more abstract mathematical concepts, Robinson decided to study at the University of California at Berkeley, from which she graduated in 1940. Discouraged by employers' lack of respect for her intellectual abilities, Robinson returned to Berkeley for graduate school. Her assistant professor Raphael M. Robinson taught her number theory. She married him in 1941, but could not continue her employment in Berkeley's mathematics department because of nepotism rules. Instead, she joined the Berkeley Statistical Laboratory as an assistant to Jerzy Neyman, who was working on classified World War II projects. After the war, Robinson focused on obtaining a doctorate. Directed by Alfred Tarski, a logician, she wrote a thesis on number theory that explored how integers could be defined by the addition and multiplication of rational numbers. She graduated in 1948.

Along with her colleagues, Robinson then concentrated on solving Hilbert's Tenth Problem, so named because it was the tenth query posed on a list compiled by David Hilbert, who had wondered if a method could be devised to solve a Diophantine equation (a polynomial equation with several variables) using integers. Robinson wrote academic papers addressing various mathematical questions but essays on Hilbert's Tenth Problem comprised the majority of her professional publications. In 1961 she coauthored a paper with Martin Davis and Hilary Putnam. The two, who had contacted her after she spoke at the 1950 International Congress of Mathematics, sent her a theorem that they had been contemplating. The trio's paper stated that no algorithm existed to determine if an exponential Diophantine equation could produce a solution with natural numbers. Their ideas ultimately helped Yuri Matijasevic prove the absence of the desired method in 1970. Robinson later initiated working with Matijasevic and traveled to the Soviet Union to further explore his findings.

Robinson also applied her mathematical abilities to theoretical analysis for the RAND corporation and to hydrodynamics projects conducted by the Office of Naval Research. Appointed a full professor at Berkeley in 1976, she taught classes there, despite health problems exacerbated by scar tissue from her childhood ailments. She was the first female mathematician elected to the National Academy of Sciences, being honored in 1975. Five years later, she was the second woman to present an American Mathematical Society Colloquium Lecture. She also delivered the 1982 Emmy Noether Lecture for the Association for Women in Mathematics. In 1982 Robinson became the first woman selected as president of the American Mathematical Society, where since 1978 she had been one of that group's first female officers. She also received an honorary degree from Smith College and the $60,000 MacArthur Foundation Prize Fellowship in acknowledgement of her accomplishments in mathematics. Suffering from leukemia, Robinson died on July 30, 1985, in Oakland, California.

ELIZABETH D. SCHAFER