# De Witt Sumners named an inaugural fellow of American Mathematical Society

Little did Florida State University Professor Emeritus De Witt Sumners know that the merit badges he earned as a Boy Scout for tying all kinds of complicated knots would serve as a harbinger for his much later and greater success with knots. In September, Sumners was named to the first-ever class of fellows of the American Mathematical Society (AMS) for his lifetime of pioneering work on the mathematical principles behind knots and for applying knot theory to DNA structure and function.

"This is a tremendous honor for De Witt and FSU,” says Sam Huckaba, interim dean of the College of Arts & Sciences and himself a math professor. “The inaugural class of fellows of the AMS includes the most accomplished and distinguished mathematicians in the profession. On behalf of the college, I stand in applause."

As Huckaba’s indicated, being elected during the first year of the program is especially prestigious. Currently, the AMS has about 30,000 members, and it was planning to offer fellowship status to about 800 members during the first year of the program, according to a **fellowship proposal on the AMS website**. After the first year, AMS plans to add about 75 new fellows each year until the fellowship ranks number about 1,500 people, or about 5% of the total membership of AMS.

“It is a great honor for me to be named an inaugural AMS fellow,” Sumners says. “Being elected a fellow by one’s professional peers is as good as it gets.”

Although Sumners has been officially retired since 2007, he still maintains an active research agenda in an area of pure mathematics known as topology, including being invited to spend September and October 2012 at the Isaac Newton Institute in Cambridge, England to participate in the program “Topological Dynamics in the Physical and Biological Sciences.”

De Witt Sumners is in Cambridge, England in September 2012 at the Isaac Newton Institute with his wife, Neddy (left), and with his former Ph.D. student Mariel Vazquez.

“Topology is the study of the shape of flexible objects,” the mathematician says by email from England. “When can one thing be deformed into another, and when is it impossible to deform one object into another?”

There is some career symmetry to his being in Cambridge after retirement, as Sumners first went there in 1963 as a Marshall Scholar and then stayed on to earn his doctoral degree in 1967. Later that very same year, he joined the Department of Mathematics at Florida State University faculty, where he earned tenure; won the Robert O. Lawton Distinguished Professorship, the university’s highest award to one of its own; and eventually served as department chair for six years. In 2004, he was elected a Fellow of the American Association for the Advancement of Science (AAAS).

Yet you might say that untangling the mathematical mysteries of knots has been the central theme of Sumners’s professional life.

“My Ph.D. from Cambridge University was in knot theory, a branch of pure mathematics that studies spatial entanglement of strings,” Sumners says. “It turns out that this branch of pure mathematics is applicable in molecular biology because DNA is a long stringy molecule, and DNA entanglement is a problem that cells must solve in order to survive. Proteins are large flexible molecules that interact with DNA, and topology can be used to compute spatial protein-DNA interaction that is vital to cellular metabolism.”

While at Cambridge this fall, **Sumners holds a Microsoft Distinguished Visiting Fellowship** and has served as a co-organizer of a Newton Institute Workshop on DNA topology. He also has been named a visiting scholar at Pembroke College, Cambridge for his two-month stay, a designation that gives him “high table” privileges.

To envision “high table” dining, just picture the wizards table in the Harry Potter series. While Sumners will probably not have to wear a robe at high table because he is a guest, he does indeed recall his robe-wearing days as a student.

“In the old days (the ‘60s when I was at Cambridge), everyone wore robes to dinner in the evening—the fellows at high table, and the students at the other tables,” Sumners says.

“Also in the old days, students and lecturers wore robes to lectures, and one saw the robes flapping in the breeze as the students went by on bicycles. The students were required to wear robes in the evening when they went out to pubs, etc., and there were Cambridge University officers (the proctor and the bulldog [constable]) in Elizabethan collars going about town checking on students to enforce the robe requirement.”

Sumners remembers one particular evening when he ditched the robe requirement.

“One time they caught me with my wife coming out of a restaurant, but I told them I was an American tourist and got out of the problem.” He explains that, when caught, “one had to go have a glass of sherry with one’s college advisor and get chastised about the robe requirement.”

Sumners adds that it is great to be in Cambridge for an extended period for the first time since his student days.

“My wife and I are enjoying seeing friends from those days, and visiting places remembered—like the Eagle pub, where Watson and Crick announced the double helix structure of DNA; punting [boating] on the [River] Cam in the late evening with the soft light illuminating the backs; and high tea at Grantchester,” Sumners says. “We are really enjoying being back in Cambridge.”

When he is back home in Tallahassee, the knots that Sumners ties these days are used to secure stuff in the back of his pickup truck rather than to earn merit badges. But as long as there are knots in the world, there are still practical mathematical problems to be solved.

In addition to his work on DNA, Sumners is the co-author of a theorem that says if you take a sufficiently long random string, there is a high probability that it is knotted.

“It is a phenomenon well known by those who use extension cords,” he says. “The 25-foot cord is much easier to untangle than the 100-foot cord. It’s a topological version of Murphy’s Law.”

A knotty problem indeed.