Derek Brehm: Applying Physics Outside the Field

When Derek Brehm left the Marines to start college, he hadn’t yet decided what he should study. Then he began reading popular science books that left him with questions only a physicist could answer. His next step became clear. “Nothing brought my imagination to life like physics,” he says.

He studied astrophysics at George Washington University, where he used machine learning to classify celestial objects using early classification algorithms. He then went on to study theoretical physics at Johns Hopkins. “I was not a good theorist,” he says. “I had good ideas, but I was slow at making progress.”

After three years, Brehm switched to experimental particle physics. Research he conducted at CERN included looking for signatures of theorized particles. He found that the data science techniques involved in analyzing this information was a better fit for him, something a former professor had once predicted. “One piece of advice is to take other people’s advice,” Brehm says with a smile.

Soon after graduation, Brehm was alerted to an opportunity in the Cost Assessment and Program Evaluation office at the US Department of Defense. Today, he’s an operations research analyst for the office, which provides the department with data used to support strategies and draw up budgets. Among Brehm’s colleagues are chemists, biologists, economists, and fellow physicists.

The work allows Brehm to use the skills he developed when conducting statistical analysis and designing particle experiments. “I’m still solving problems,” he says. “I still do programming and data science. I just analyze different things.”

An example case might involve looking at whether the Defense Department’s buildings and platforms are resilient in the face of climate change. How, for instance, does the changing salinity of the ocean affect US ships? Based on his findings, Brehm is then tasked with developing a range of possible solutions. “I think about the problems critically, break them down, and consider how I might solve them, step-by-step,” he says.

Brehm’s division receives new assignments each year, and the promise of fresh topics and analytical techniques appeals to the lifelong learners that most PhDs are, he says. Still, unlike academia, it’s an environment that values timely answers over comprehensive ones. As a PhD physicist there’s a tendency, Brehm says, to attempt to fully solve a problem by examining every possible detail. Instead, he offers policymakers and government leaders a mostly correct result that might take another 18 months to fully explore.

“You don’t have time to search out all the nooks and crannies,” he says. “You need to get a close enough answer that will help someone get to two or three possible solutions. The details that are fun and exciting are sometimes not what’s needed.”

For those interested in work of this kind, Brehm advises first being open to a career outside academia. “There are a lot of opportunities in the private and public sector for a PhD physicist,” he says. “You know how to do analysis. You know how to work with machine learning algorithms. Now you can just apply it to something else.”

The views of the interviewee are his own personal views and are not necessarily the views of the Department of Defense or of the United States Government.