Alex Yee

# A numerical sensation

## McCormick sophomore Alex Yee breaks mathematical world record

Most students find finals week to be one of the most stressful times of the year. They spend late-night hours cramming for exams and finishing up projects, looking forward to the end of the quarter. But the stresses of finals didn’t stop Alex Yee, a sophomore majoring in computer science, from finishing a project he’d been working on since high school — and breaking a world record in the process.

Yee made headlines around the country early this year by calculating the Euler-Mascheroni constant to more than 116 million digits, easily surpassing the previous record of 108 million set in 1999. The achievement was the summation of a project Yee started as a senior at Palo Alto High School in California. The assignment for his AP computer science class was to create a program that would add, subtract, multiply, and divide large numbers. Yee completed the assignment, but that was only the beginning of his work.

“After the homework was due, I carried on with the project to the point that I could do everything that a graphing calculator could do, except much faster and with much larger numbers,” Yee says. “At some point I put in the capability of computing constants, and then I started running down the list of constants.”

Around October of 2006, Yee found that his program could compute the Euler-Mascheroni constant with unusual speed. The constant is considered to be the third most famous constant, behind pi and e. While the calculation may be beyond the comprehension of most people, it is commonly used in numbers theory and high-level mathematics. “I saw that my program could compute it about as fast as some of the commercial products available, and I knew that I could make it faster,” he says. “I realized that the record of 108 million was beatable.”

Yee spent all of his free time between October and December refining the program to better calculate the constant. Once finals week came around, Yee didn’t need his laptop for classes and could devote the four days needed for the program to calculate the constant.

After 38 hours of computation and 48 hours of verification, Yee determined that he had broken the record. “I just stood there in disbelief,” he says. “Finally I picked up the phone to call my dad and told him that I had done it.”

If it wasn’t impressive enough for Yee to break the record as a college freshman, he also did it on an ordinary laptop — and not a supercomputer or server typically required for this kind of work. “My program is a lot faster and more efficient than other existing programs for laptops,” he says.

“The result itself doesn’t have great practical use, but the method he used to compute it is what’s really interesting,” says Robert Dick, assistant professor of electrical engineering and computer science. “The program and the methods he used to calculate this are a real contribution.”

In the months since Yee’s achievement became public, other mathematicians have already claimed to have broken his record. That doesn’t bother Yee — in fact, he anticipated it. “At the time I broke the record it had been standing for seven years, but I knew that it could probably be broken again soon,” he says. “But I’m not sure that anyone has broken it using a laptop. It would most likely be done on a really fast computer.”

Yee hasn’t spent his time defending his record but has moved on to something he describes as “more practical” — research on compression algorithms with Robert Dick.

—Kyle Delaney