Advances in microbial oceanography, cosmology, mathematical logic yield honorary degrees

University Communications

Oceanographer David Karl, astronomer Robert Kirshner and mathematician Anil Nerode will receive honorary degrees from the University of Chicago during the 503rd Convocation Ceremony June 12 on the Main Quadrangle.

Karl is a professor of oceanography at the University of Hawaii. His research has taken him to Antarctica more than a dozen times. He has participated in more than 70 major oceanographic cruises and 30 dives on research submersibles.

A member of the National Academy of Sciences, he also has received the Bigelow Medal in Oceanography from the Woods Hole Oceanographic Institution among his many honors. The impact of Karl's papers, which have been cited more than 12,000 times in the scientific literature, has been broad. Karl's colleagues in the National Academy of Sciences consider his work to be "innovative and consistently excellent." One NAS member wrote in a supporting nomination letter: "One could teach an entire graduate seminar in ocean biogeochemistry based solely on his [Karl's] papers."

"Karl is arguably the leading researcher in the world today in the fields of marine microbiology and marine biogeochemistry," wrote Albert Colman, Assistant Professor in Geophysical Sciences, in his letter nominating Karl for an honorary degree. "These fields are critically important in that they help us to understand how marine ecosystems function both undisturbed and in a warming, elevated CO2 world."

"In the late 1980s, Karl established the Hawaii Ocean Time-series, an oceanographic station in the heart of the world's largest biome, the North Pacific Subtropical Gyre. The high-frequency measurement campaign at HOT, continuing to this day, has rewritten numerous paradigms regarding nutrient limitation, carbon fluxes, and biogeochemical variability in oceans," Colman wrote.

During the 1980s, Karl directed the microbial component of one of the first sustained interdisciplinary studies of carbon dynamics in the oceans, which spanned the 1980s. This work revealed the major role of bacteria in mediating carbon fluctuations in the surface ocean and from the surface to deep-ocean. Much of this work linking microbes to carbon and nutrient cycling now is a staple of oceanography textbooks.

Kirshner is Harvard College Professor of Astronomy and Clowes Professor of Science at Harvard University. He is considered to be one of the leading cosmologists of his generation and the premier observer of supernovae, or exploding stars which manufacture the heavy elements that later become incorporated into planets and people. He also has made key contributions in mapping the distribution of galaxies in the universe. Supernovae played the central role in the discovery that the expansion of the Universe is speeding up and not slowing down.

Science magazine named the accelerating expansion of the universe as the "Science Breakthrough of the Year for 1998." The High-Z Team, of which Kirshner was a member, and another group independently used supernovae to make this discovery, which revealed the presence of mysterious "dark energy." Dark energy accounts for three-quarters of the Universe and has repulsive gravity.

"When he began his graduate career at Caltech, supernovae were little more than a curiosity because of the difficulty of getting quality data on these rare events that occur about once per 100 years in a typical galaxy," wrote Michael Turner, the Bruce V. & Diana M. Rauner Distinguished Service Professor in Astronomy & Astrophysics and the College, and Joshua Frieman, Professor in Astronomy & Astrophysics, in their nomination letter.

"Today, thanks in large measure to the efforts of Kirshner and the students and postdocs he has trained, high-quality data are obtained on hundreds of supernovae per year," Turner and Frieman wrote.

Kirshner and the High-Z Team shared the Gruber Prize for Cosmology in 2007. He is a member of the American Academy of Arts and Sciences, the National Academy of Sciences and the American Philosophical Society.

Nerode, AB'49, SB'52, SM'53, PhD'56, is the Goldwin Smith Professor of Mathematics at Cornell University. No other scholar has exerted a more profound impact upon the fields of mathematical logic and theoretical computer science than Nerode, says Robert Soare, the Paul Snowden Russell Distinguished Service Professor in Computer Science and Mathematics.

Nerode completed his PhD at UChicago under the supervision of the late Saunders Mac Lane, a recipient of the National Medal of Science. Nerode went on to mentor 50 PhD students of his own and now counts nearly 500 mathematicians and computer scientists among his academic descendants.

"He showed them how to analyze a structure, find algorithms for it when they existed, classify the relative complexity of the others, and to do so preserving the beauty of the underlying mathematics," Soare wrote in his nomination letter.

One of Nerode's colleagues has compared him to the German philosopher and mathematician Gottfried Leibniz (1646-1716). The comparison is appropriate, according to Soare. "Leibniz and Nerode were both child prodigies, and both absorbed an immense amount of mathematics very early in their careers," Soare wrote. "Most important, both had a vision and a passion for discovering and understanding effectively calculable processes across the entire span from the theoretical to the practical."

Nerode has consulted for more than 20 organizations, including the Institute for Defense Analysis, IBM, the National Science Foundation, and Argonne National Laboratory. He also has served as editor of nine journals, among them the Journal of Symbolic Logic, Annals of Pure and Applied Logic, Future Generation Computing, and Computer Modeling and Simulation.