Robert Osserman, professor emeritus of mathematics, died Nov. 30 at his home in Berkeley. He was 84.

He joined the Stanford faculty in 1955 and served as chair of the Department of Mathematics from 1973 to 1979. He was the Andrew W. Mellon Professor of Interdisciplinary Studies from 1987 to 1990.

From 1990 to 1995, he served as the deputy director of the Mathematical Sciences Research Institute in Berkeley, an organization that he helped to found in the early 1980s. He helped it become one of the world’s premier research centers for mathematics and served as its director of special projects until his death.

During his long career, Osserman held visiting appointments at the University of Colorado, the Courant Institute, Harvard and the University of California-Berkeley, and was also the recipient of Fulbright and Guggenheim fellowships. In 1960-61, he was head of the Mathematics Branch of the Office of Naval Research in Washington, D.C.

Osserman received his PhD from Harvard University, where he wrote his thesis under the direction of Lars Ahlfors. He initially worked in the field of Riemann surfaces and complex analysis. Early in his career, he became aware of minimal surfaces – mathematical generalizations of soap films – that minimize area among all surfaces with the same boundary.

As far back as the 18th century, mathematicians studying minimal surfaces wrestled with questions that were easy to state but stubbornly difficult to solve, until Osserman and Ahlfors made important breakthroughs.

## Mathematical study of minimal surfaces

Osserman was able to exploit the classical connection between formulas that represent these surfaces and complex analysis. He created far-reaching extensions of this relationship, and then used these insights to resolve many open questions in the field. His monograph Survey of Minimal Surfaces, first published in 1969, with a second edition in 1986, remains a standard reference in the subject and has introduced this beautiful subject to generations of mathematicians.

Minimal surfaces and their generalizations are central to geometric analysis, an area of research that has connections to many areas in physics, the calculus of variations, Riemannian geometry and partial differential equations. During his tenure as chair of Stanford’s math department and for the decade that followed, Osserman played a key role in hiring and nurturing many of the world’s best mathematicians in this area, helping the university to become a world leader in this very important field of mathematics.

Osserman authored or co-authored more than 70 research papers. He was the thesis supervisor for nine graduate students, many of whom have gone on to be successful researchers and professors in geometry, topology and computer science.

“Bob Osserman was my thesis adviser, my colleague and my very dear friend,” said Blaine Lawson, who was his first PhD student and is now a professor of mathematics at Stony Brook University and a member of the National Academy of Sciences. “He was a mentor of tremendous influence in my mathematical development and on my outlook on mathematical life. He was a man of immense erudition and personal warmth and charm.”

Osserman was a much-loved teacher and in 1985 received a Dean’s Award for teaching. For several years in the 1980s he collaborated with Professors Sandy Fetter, physics, and James Adams, mechanical engineering, to design and teach the course Values in Technology, Science and Society. This was an innovative project intended to teach mathematical, physics and engineering principles to undergraduates majoring in nontechnical fields.

That experience was the beginning of an exploration that led to him to write P*oetry of the Universe: A Mathematical Exploration of the Cosmos*, which was published in 1992. The popular science book brought in themes from Dante and elsewhere to describe the geometry behind modern cosmology. He was elected a fellow of the American Association for the Advancement of Science in that same year.

## Helped create the ‘Fermat Fest’

In July 1993, he was part of a team that created a public event (the “Fermat Fest,” at the Palace of Fine Arts Theater in San Francisco) about Fermat’s Last Theorem, a proof of which had been announced a little less than two months earlier.

After the Fermat Fest, Osserman became more involved in the public presentation of mathematics and its intersection with the arts. A conversation he conducted with playwright Tom Stoppard on “Mathematics in Arcadia” was the first in a series of public Conversations with Bob Osserman he conducted with artists and musicians, including Steve Martin, Michael Frayn, Persi Diaconis, Merce Cunningham and the musicians of the Merce Cunningham Dance Company, Alan Alda, Philip Glass, origamist Robert Lang and pianist Christopher Taylor.

In 2010 Osserman published two papers about the shape of the Gateway Arch in St. Louis, one in the *Notices of the American Mathematical Society*, the other in an architectural journal, and produced an accompanying video explaining the mathematics of its curve. Less than two months before his death, he held a final public Conversation with James Simons, a mathematician, financier and philanthropist. Videos of most of these events are available on the MSRI website.

Born 1926 in New York City, Osserman grew up in Washington Heights and attended the Bronx High School of Science, where he was a member of the first class that entered as freshmen. As a young man he had interests in music (piano and voice) and in many areas of science, including astronomy and entomology, interests that he pursued throughout his life; in 2004, he traveled to Princeton to see the hatching of a family of periodical cicadas.

He served in the Air Corps at the end of World War II. Deployed to Japan in the second half of 1946, he repaired airplane navigational signal equipment. This background was useful when, in 2004-05, he chaired the committee charged with preparing materials for the April 2005 Mathematics Awareness Month, whose theme was “Mathematics and the Cosmos.”

With astronaut Michael Foale, he produced a film called *The Right Spin*, about the use of mathematics to put the space station Mir into a regular spin after a failed docking attempt induced a tumbling motion that prevented the solar panels from facing the sun. Without power, navigation was impossible, evacuation was inevitable, and Mir would have burned up re-entering Earth’s atmosphere. The film is available as a DVD from the American Mathematical Society.

Osserman lived since the early 1980s in Berkeley, where his wife, Janet Adelman, a noted Shakespearean scholar, was a professor in the English Department at UC-Berkeley. She died in April 2010. He is survived by his first wife, Maria Osserman; their son, Paul, of Cobb, Calif.; two sons with Janet: Brian of Davis, Calif., and Stephen of Portland, Ore.; and one grandchild.

A memorial service will be conducted by the Department of Mathematics at a later time. The family requests that memorial donations be made to any of the following organizations: Nature Conservancy, Mendocino Land Trust, San Francisco Chamber Orchestra, California Academy of Sciences, Mathematical Sciences Research Institute and Kehilla Community Synagogue.