Student Sets Pi Day Record

Reese Petersen, an 18-year-old physics major from small-town Minnesota, broke a BYU record last week when he recited 806 digits of pi from memory at the student Pi Day celebration.


Later that afternoon, at a different Pi Day party hosted by the Society of Physics Students, Petersen recited 838 digits of pi. 


Each time, it took Petersen about 8 minutes to rattle through more than 800 digits.  “If it weren’t for the pauses,” Petersen said, “I think I could do it in five minutes.”  The pauses are when Petersen's recalling the mnemonic device he invented for the next string of numbers. 


“After digit 120, there are a lot of palindromes and repeating patterns,” Petersen said.  He started memorizing about three weeks before Pi Day, and most of this time was spent locating these palindromes and repetitions.


For the first 120 digits of pi, however, Petersen doesn’t need any mnemonic devices.  He has these numbers memorized by their sound.  To Petersen, these digits resemble a song, with each number having a different pitch and strings of numbers resembling  melodies then variations on those melodies.  Relying on his 10 years of piano experience, Petersen compares memorizing pi to memorizing a piano piece:  “After a while, you don’t think about the notes; your fingers just know it.” 


Because Petersen had the first hundred digits memorized vocally instead of mentally, he had to be careful not to talk too slowly at the Pi Day competitions.  “I have to maintain a minimum speed or else I’ll get stuck.”


Petersen was recently called to serve for the next two years in the Thailand Bangkok mission.  When he gets back, he plans on working to beat his record, but right now, the world record isn’t a goal.  Instead, Petersen hopes to earn a PhD in physics then work in research and development of nanotechnology applications.


Photography: ASHLEY FRANSCELL/Daily Herald