The face of math is changing, and mathematics professor Kenneth Brown epitomizes that transformation. Though he used to be a solitary sort of mathematician, "it's becoming less and less common for people to work alone," he said. "Getting together and talking to other people is the way most of the work gets done nowadays. Collaboration is really a crucial part of the work."

Malott Hall, home of the math department, provides physical proof of the importance Brown and his colleagues place on collaboration. The long halls are broken by benches inset in the walls for casual meetings; the large math lounge offers four separate arrangements of armchairs and couches. Chalkboards cover three of the walls for spur-of-the-moment equations.

The nearly 100 colleagues and current and former students of Brown who attended the Oct. 9-11 "Approaches to Group Theory" conference in his honor testify to the importance of face-to-face contact for mathematicians. So many people attended that the banquet room couldn't hold them all, according to organizer and mathematics professor Karen Vogtmann.

"Ken's such a quiet and humble person it's easy to forget that his mathematics and his work have influenced so many people," said Laurent Saloff-Coste, chair of the math department.

One pleasant surprise at the conference came from former Cornell postdoctoral researcher Kai-Uwe Bux, now in Germany, who reported that he had solved a problem Brown had formulated in the first edition of his seminal work, "Buildings." "It was really nice to see it solved," said Brown with a smile.

Group theory, Brown explained, is "a very beautiful, elaborate theory that's developed from the study of symmetry. Buildings are geometric objects made of things someone called apartments because they were divided into pieces called chambers -- no applications to architecture at all."

Melanie Stein, M.S. '88, Ph.D. '91, a conference speaker and a professor at Trinity College, said that "without Ken's mentoring and guidance I would not have a career in mathematics. He is as patient and kind a person as you could find, very nonjudgmental and accepting of others. The combination makes him a wonderful teacher and mentor." Cornell agrees: Brown has received both the Clark Teaching Award and the Mathematics Department Senior Faculty Award.

Although Brown characterizes himself as "basically a pretty shy person," he said he thoroughly enjoyed the conference, which many of his former students helped organize, and felt honored by it. He particularly appreciated the effort the speakers made to be understandable to the audience. This in itself was a testimonial to Brown, who has "an uncommon clarity of thought and expression," said Saloff-Coste.

"I like being able to show students there's something beautiful they weren't able to see before," said Brown. And because he loves teaching so much, he's chosen a phased retirement so he doesn't have to give it up right away.

Cornell was Brown's first -- and last -- job after he received his Ph.D. from the Massachusetts Institute of Technology in 1971. He served as chair of the department, 2006-10, and in summer 2009, directed the Summer Math Institute.

"I love Cornell," said Brown, an avid tennis player and local choral singer. "The department is very friendly; we don't have infighting. Here you knock on someone's door, and they're always open to talk to you."

Brown is also the author of "Cohomology of Groups"; both his books have been extremely influential works, according to Stein and Saloff-Coste. "What I really like the most is when different subjects that don't seem to have anything to do with each other get connected. That's when math gets really fun," said Brown.

Linda Glaser is a staff writer for the College of Arts and Sciences.