From bonsais to jet engines, computer scientist Darrell Whitley’s work cultivates new approaches

darrell whitley and his bonsai treesDarrell Whitley didn’t set out to be an internationally known computer scientist – or an award-winning bonsai cultivator. But, following his passions, he has accomplished both. And he recently joined the Colorado State University College of Natural Sciences Dean’s Office for a year as acting associate dean for academics.

Whitley, who is a professor of computer science, has built a career in machine learning and optimization, with his work being applied to jet engines and satellites. In his spare time though, he gets offline, way offline – turning to work with his many miniature trees. Last year, he was named Featured Bonsai Artist of the Year by the Denver Botanic Gardens,  which hosted his work in a solo show.

But Whitley’s early academic career found him neither at a computer terminal nor trimming tiny branches. Far from it.

Archeologist to computer scientist

Whitley began his academic career digging for archaeological artifacts in Mexico and studying local cultures in India. He received his B.A. in anthropology and geology and continued his studies in anthropology, earning his Ph.D.

While he was studying evolutionary and population dynamics, he was drawn to mathematical approaches to the research. He had started taking computer science courses on the side and found himself more and more engaged in the power and potential of the discipline. Soon he was teaching these classes as a computer science graduate student. As he was finishing his graduate degree in 1986, Whitley arrived as an assistant professor of computer science at CSU.

Optimizing learning

Whitley’s focus on machine learning and optimization has ties to his evolutionary research roots.

“The background I had in evolutionary theory and population genetics from anthropology did help me,” he said. “The simulated evolution I do is very close to optimization, and optimization shows up in machine learning, but it also shows up in all sorts of design, scheduling and all types of different problems. The cool thing about evolutionary algorithms is that they make no assumptions about what the solution is going to look like.”

That has led to highly efficient machine-developed solutions that no human would have considered.

This approach has allowed his work to help GE engineers design a better engine for the Boeing 777 and has helped the U.S. government schedule satellite communication – and even track space junk. In the case of the jet engine, he said, “they were trying to design an engine that was as fuel efficient as possible, and the algorithm just found an engine design that was radically different than anything that had been seen before,”  adding that he enjoys seeing these real-world applications of his research.

Whitley served as chair of the CSU computer science department from 2003-2018 – a busy 15 years for the department. In just the past 10 years, the number of majors has more than doubled, from about 300 in 2008 to about 750 in 2018, and interest from students in other disciplines has burgeoned as well. In his tenure as chair, Whitley helped to build a department known for exceptional research – from artificial intelligence to security – and thoughtful instruction. “You just hire good people and try to help them do the things they need to do,” he said.

darrell whitley tends to his bonsai trees

Grand vision – in miniature

A few years after joining CSU, Whitley found himself stumbling onto yet another passion: bonsai. “I saw a collection in 1990 in Delray Beach, Florida, and thought it was completely cool,” he said. When he returned home to Fort Collins, he decided to try his hand at the practice.

“For the first couple years, I tried to do things on my own, and that didn’t work so well,” he said with a smile. But he soon found the Rocky Mountain Bonsai Society, “and once I got connected with them, things started improving.”

He has been honing his practice ever since. It is a balance of science, in keeping the trees healthy, and of art, in shaping the trees into elegant designs – “it takes both,” Whitley noted. He has not contained his work to traditional species. Although he has some junipers and maples in his collection, he has focused in large part on local Colorado species, such as lodgepole pines and limber pines.

Whitley has started his trees from all sorts of sources. “I’ve grown them from cuttings, and I’ve used trees from Home Depot,” he said. He has even collected native species from the Roosevelt National Forest near Red Feather Lakes. “It’s the same place you can get your Christmas tree,” he said. In the summer, you can pay the same fee to collect a tree as well.

Some of his current plants are about as old as his bonsai hobby – nearly 30 years. Others, such as those collected from the mountains, could be as old as 400 years.

Next steps

Whitley stepped down from his role as chair last June, handing the reins over to Professor Craig Partridge. He has now brought some of his ficus bonsais to enjoy the southern exposure in his new temporary workspace in the Dean’s Office while he serves in place of mathematics Professor Simon Tavener, who is on sabbatical. After that, Whitley will be back to his role as full-time faculty in the computer science department, teaching as well as working on his research. And, of course, making time for his tiny trees.