Making stronger connections

Ken Kelton’s not sure how or when it started, but he got the science bug early.

His fascination might have been sparked by the chemistry set his older sister bought him when he was just 5 years old.

And it was later fed by the freedom he had as a young boy growing up in rural Arkansas to experiment with chemistry projects that he admits he might not allow as a parent today.

Kelton recalls with great glee making gunpowder for his sixth-grade science project; the most amazing part was that his teacher actually let him demonstrate it outside to the class.

“I also made rockets and rocket fuel,” he says. “I burned the field by our house — my dad had the fire department out I think two or three times. It wasn’t until one of my homemade rockets actually did get off the ground and landed on top of the house while it was still burning that he decided that the rockets had to stop.”

But his father, John — who, like Kelton’s mother, Helen, lacked a high-school education — was a wise man. While he insisted that rocket building had to stop, learning would not.

John and Helen wanted their son to have a college education, but because there was no college in Hot Springs, Ark., where they lived, and no way to afford sending him off, they moved to Russellville, Ark., home to Arkansas Polytechnic College (now Arkansas Tech University). They had heard that it was a very good school, and Ken could attend it while living at home.

His parents’ sacrifice was not wasted. Four degrees later, including two from Harvard University, Kenneth F. Kelton, Ph.D., today is Washington University’s first Arthur Holly Compton Professor in Arts & Sciences and its new chair of the Department of Physics.

‘Highly regarded’

Kelton is an expert in a phenomenon called nucleation, which is the most common way that physical systems change from one phase to another — such as the formation of a crystal from a liquid — and is a governing process in nearly all phase transformations.

His book “Nucleation in Physical and Biological Systems,” co-written with Professor A. L. Greer at Cambridge University, is scheduled to be published next year by Elsevier. It is a comprehensive review of the phenomenon of nucleation in everything from solids and cells to beer and champagne.

Within the field of materials physics, Kelton has particular interests in the study and production of novel phases such as titanium-based quasicrystals and metallic glasses; experimental and theoretical studies of time-dependent nucleation in condensed systems; investigations of the relationship between developing short-range order in supercooled liquids and nucleation processes; and studies of the potential use of quasicrystals for hydrogen storage.

“Ken is highly regarded by the national and international community of researchers in materials physics,” says Patrick C. Gibbons, Ph.D., a WUSTL professor of physics who has known Kelton since 1984 when Kelton came to interview as assistant professor of physics. Kelton joined the physics department in fall 1985 after a two-year postdoctoral fellowship at Harvard. The two have collaborated on projects ever since.

“Most physicists are either experimenters or theorists, but usually not both,” Gibbons says. “Ken is an exception in that he has done theoretical work and computer simulations of nucleation and growth processes, usually in amorphous metal alloys that are beginning to crystallize during heat treatments.”

And Kelton, who directs the Laboratory for Materials Physics Research, has a special trait, according to Gibbons: “He is able to persuade colleagues that difficult new projects are worth undertaking.”

Using an electrostatic levitator — a complex, highly sensitive instrument that Kelton persuaded NASA researchers to move from the Marshall Space Flight Center in Huntsville, Ala., to the Advanced Photon Source at Argonne National Laboratory in Chicago — he led a research team in 2003 that validated a 50-year-old hypothesis explaining how liquid metals resist turning into solids.

The research made a splash in the scientific community, appearing in Physical Review Letters and as the cover story for the July 2003 issue of Physics Today, illustrated by a striking photo of a solid drop of metal suspended inside the levitator.

“What we’re trying to do is to better understand how phases crystallize, how they change from one phase to the other, because if you can control that, then you can control what’s called the microstructure,” Kelton says. “If you can control the microstructure — that’s how parts of the new phase are put together, how big they are, how they’re joined — you can control the properties.”

An example of work his research group is doing is a project for the Air Force: “We’re trying to look at how you could take aluminum-based metallic glasses and process them to make them into strong materials for airplane applications.”

The ‘ah-ha moment’

Since taking over as chair in July, he has had to make a great sacrifice of his own — giving up teaching, except for one graduate course, “Materials Physics I.”

As science has “just fit” him for as long as he can remember, he also has always enjoyed explaining things to others.

Whether it’s been as a third-grader helping the second-graders with their math or reading or as a senior at Arkansas Polytech designing lab work for freshmen or as a master’s degree student at the University of Tennessee teaching his first course, Kelton has found showing students the “ah-ha moment” to be “thrilling.”

“The most fun is where you’re teaching them something, and you can see when you make that connection,” he says. “Where they go, ‘Oh!’ And it puts a piece in the puzzle for them, and they can see how this relates to something else or how they understand this better. That is to me the most exciting time, when you can really see that you’ve helped them make certain leaps in their own understanding.”

Because he has had many mentors along his academic path giving him opportunities to experience the excitement of research and of discovery, Kelton is quick to do the same for his students.

He first invited an undergraduate physics major to do research in his lab in 1987. Philip N. Sabes, Ph.D., an associate professor in the Department of Physiology at the University of California, San Francisco, recalls that experience.

“Ken was absolutely wonderful as a research mentor,” says Sabes, who earned a bachelor’s degree in 1989. “He was generous with his time and energy, he was a good teacher, and he gave me excellent opportunities to grow as a student and scientist.

“In my senior year he let me present a talk at the annual American Physical Society meeting — quite a rare thing for an undergrad to do. He did this despite the fact that it was reasonably important work, and there is no doubt he would have presented it better.

“Ken was my first scientific mentor and, in many ways, the best — and I’ve been in science for over 18 years,” Sabes says.

Kelton has served as advisor to 22 graduate students and two postdoctoral scientists. One of those graduate students he advised, along with Gibbons, was Ann M. Viano, Ph.D., associate and J. Lester Crain Professor of Physics at Rhodes College and president of Sigma Pi Sigma, the national physics honor society.

“Ken provides a very encouraging atmosphere and makes himself very accessible but also allows his graduate students to investigate, learn and connect ideas on their own,” says Viano, who earned both her master’s degree (1994) and doctorate (1996) in physics from WUSTL.

“This independence is essential to the development of excellent physicists,” she says. “I learned a great deal from Ken — not just how to go about planning and executing important experiments, but how to lead effectively without demeaning or undermining the confidence of those who are still learning. I use this same approach with my own students today.”

In his new role as chair, Kelton will be using his skill to lead effectively on a larger scale.

He has a number of goals in mind, with the most important one being strengthening the ties physics already has with departments and making new ties with others.

“Everything I’ve done throughout my career would be characterized as interdisciplinary,” says Kelton. “I see the connections that you make to other disciplines as being critical — I’d very much like to make stronger connections, so I’m reaching out as much as I can.”