Have you ever watched the TV show, Numbers? You know, the one where a mathematics professor uses maths to solve crimes? Well, this month I’ve come across a real-life version of this (in fact, he also consults for the show to make sure the maths is fairly ‘honest’). But this mathematician isn’t just solving tough crimes (although he is doing that too), he’s using it to beat terrorism.

Dr Jonathan David Farley is a research mathematician. That in itself is not all that common. His main areas of research are lattice theory and the theory of ordered sets and he is doing some amazing work in several distinct areas. But the most intriguing, I think, is his work on counterterrorism.

A Lieutenant Colonel in the U.S. Air Force said “I am familiar with this work and can attest that his thinking has influenced real-world decisions of highest operational importance to the Department of Defense.”

So, exactly how does Dr Farley use maths to fight the forces of terrorism? Well, he’s been researching quite a wide variety of factors that help terrorists operate. He’s investigated how terrorists evade capture and what governs the structure of the perfect terrorist cell and he’s also looked at the mathematics of counterterrorism efforts.

His most recent counterterrorism-related publication is called How Al Qaeda Can Use Order Theory to Evade or Defeat U.S. Forces. In it, as the name suggests, he uses order theory to investigate terrorist cell structures to determine which structure is most likely to enable a terrorist cell to continue to function in the event a subset of its members is captured. This paper specifically looks at cells that have a single leader and where no member has more than two immediate subordinates.

Now, many of us view advanced maths as boring and complicated. But that publication is the most entertaining science publication I’ve ever read. Dr Farley didn’t just describe the maths he used to investigate the problem. He turned it into a little story. Here’s how it starts:

I arrived at Ted K.’s cell. “Cell” was the wrong word: As the door swung open, I walked into what you would think of as a plush apartment. All that would strike you as strange was the absence of any windows.

“I still can’t get over how well they take care of you here,” I said, shaking my head. “Is that flat-screen TV new? I’m surprised they let you watch the news.”

Ted was sitting at a large glass table, papers with his neat handwriting littering the surface—ordered chaos. His grey-black beard and hair were as wild as ever. “Don’t worry: it’s just for playing video games.”

I highly recommend you read the entire (short) publication. But if you’re curious about the structure that works best, it’s this one:

Now, how does this actually help counterterrorism forces? Well, once they know how terrorists can protect their cells, they can take steps to overcome that protection. They also have more intelligence about the likely impacts of them having captured particular members of a given cell based on whether the cell has an optimal structure or not.

Dr Farley is a truly amazing and inspiring mathematician. When we’re at school, many of us feel that most of the maths we’re taught is pretty useless unless you want to be a pure mathematician who doesn’t get involved with any practical applications. And let’s face it, few of us ever aspire to that. But Dr Farley’s focus on fighting crime and terrorism demonstrates that learning some of the more advanced maths we get taught at school isn’t a waste of time. He’s applying maths to crucial real-world problems, and he’s even started a maths company (Phoenix Mathematics, Inc.,) so he can develop mathematical solutions to homeland security-related problems. So, if you’ve got a school-aged child, tell them about Dr Farley next time they complain about having to do their maths homework.

## Expert’s bio

Jonathan David Farley graduated *summa cum laude* from Harvard University with the second-highest grade point average in his graduating class.

Seed Magazine named Dr Farley one of “15 people who have shaped the global conversation about science in 2005.” The City of Cambridge, Massachusetts (home, of course, to Harvard University and MIT) officially declared March 19, 2004 to be “Dr Jonathan David Farley Day”.