Jeffery DelViscio: It’s Pi Day.
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This is Scientific American’s Science, Quickly. I’m Jeffery DelViscio.
Well, another 3.141592653589793238462—you get the idea day is upon us.
It’s that special day in March when we collectively celebrate the irrational number represented by the Greek symbol pi.
In the simplest definition, pi is the ratio of a circle’s circumference to its diameter.
Pi shows up everywhere in mathematics. In 1960 the illustrious Martin Gardner, then our Mathematical Games columnist, quoted mathematician Augustus De Morgan’s description of pi as “this mysterious 3.14159 … which comes in at every door and window, and down every chimney.”
Pi shows up, outside of its circular home, in the motions of springs and pendulums, probability and our 365-day calendar. It shows up in nature everywhere there’s a circle or a spiral, such as in planets and DNA. Pi even shows up in the bends of rivers—their sinuosity, specifically.
The existence of pi has also led to mass baking on March 14th, to pizza discounts and to memorization contests.
Humans have known about the existence of pi for at least the past 4,000 years. But in the past few hundred years, we have been trying to increase the precision of our calculations of the digits of pi. In 1949 the electronic computer ENIAC was used for 70 machine hours to calculate pi to more than 2,000 decimal places. Just last year Google Cloud calculated it to 100 trillion digits.
And along with the race to calculate pi has come a parallel contest to try to memorize its unending string.
Today on Science, Quickly, we talk to someone who has created another way to honor, and try to remember, the digits of pi—through song.
Devin Powell is a science writer and multimedia creator. And he joins us today.
Devin Powell: Thanks Jeff.
DelViscio: So, humans have managed to memorize incredibly long sequences of pi decimals. How did you get interested in doing this a different way?
Powell: Yeah, so, a few years ago I was challenged to one of these pi digit memorizing competitions. Nothing like the world records, you know. We were trying to get to 50 digits. And a few years prior to that I had covered the world memory championsh
