We made it through the “Pi Day of the century” on Saturday. I took a spontaneous day trip to meet friends in Idaho, so I didn’t do any pi-related activities, but I saw plenty of pi coverage in the week leading up to the big day.
I too feel a profound disconnect with this holiday! Image: Dinosaur Comics by Ryan North.
Like many mathematicians, I’m pretty lukewarm about Pi Day. I’m generally a scrooge about most holidays, but I do appreciate the fact that Pi Day has given me a chance to write about some cool math topics I probably wouldn’t have otherwise. Last year I wrote about π(x), the prime counting function, and this year, I wrote about continued fractions, which get cooler every time I learn more about them. (I can’t help but brag about the fact that Mike Lawler did some continued fractions with his kids after reading my post. I love seeing my work in action!)
Of course, there were quite a lot of nice Pi Day posts around the math blogsphere this year. Pat Ballew wrote about pi and the Kruskal count, a fun mathemagic trick. JoAnne Growney posted at at her math poetry blog about Pilish, the “language” whose word lengths follow the digits of pi. Alex Bellos wrote a short post in Pilish for the Aperiodical. Dick Lipton and Ken Regan took the opportunity to discuss another pi: products. Specifically, how much does integer multiplication cost? Rafael Irizarry wrote about empirical evidence that pi is a normal number for Simply Statistics
The Aperiodical pulled out all the stops for Pi Day. If I counted correctly, they posted 15 articles about pi this past week. I especially enjoyed their first one, a video of mathematicians using various methods, from measuring the period of a pendulum to filling water balloons, to estimate pi. I also appreciated Katie Steckles’ rumination on the appropriate time to celebrate pi in several different timekeeping systems. Aperiodical contributor Christian Perfect bought the domain three.onefouronefivenine.com, where you can scroll down and see lots and lots of digits of pi.
Education-focused blogs Math Munch, Let’s Play Math, and Moebius Noodles used the occasion to publish fun, accessible posts about pi. Stuart Price, inspired by Joshua Bowman, wrote about π-th roots of unity, which relate quite nicely to continued fractions. Mike Lawler also used that activity with his kids.
I understand why math bloggers write about Pi for Pi Day, and they write a lot of neat stuff. General interest news media, however, can get weird about it. On the one hand, it is nice for math to get a little bit more focus than it usually does. On the other hand, the stories often divide the world into “us” and “them”: regular folks and freaks who like reciting numbers. Is there really no such thing as bad publicity? As Dan Meyer said on Twitter,
Some big media outlets did pretty well on Pi Day. Phil Plait wrote a fun piece for Slate, Alex Bellos wrote a few nice posts for the Guardian, including one about the first person to use the letter π for circles, and Manil Suri wrote an op-ed in the New York Times. Gary Antonick wrote a very nice post for the New York Times Wordplay blog. He focused on Euler’s identity and included an excellent new-to-me video explaining how exponentiation works when you start messing around with complex exponents.
Daniel Ullman wrote a good article for the Conversation that includes the fantastic tongue-in-cheek suggestion to celebrate Earth Day by eating foods that start with the letter ‘e’. Or, of course, we could do that to celebrate e Day on February 7th (2/7 for the US and Belize), July 2nd (2/7 for most of the world), or September 28 (the 271st day of the year in non-leap years, 272nd in leap years—either would be appropriate as e starts 2.718). Steven Strogatz wrote a lovely article about the Pi Day dilemma for the New Yorker. Pi is an important number, and it really is stunning that is appears in so many places. It’s frustrating when our attempts to talk about it are reduced to lists of digits.
Some big news outlets…didn’t do so well. Time gave us Pi Day Deals, Freebies, and Events for Math Lovers and Haters Alike. Select quote: “There are plenty of deals meant to appeal to C students who hated math too.” Thanks for making sure we “normal people” know that it’s still OK to openly despise math! (Can you imagine St. Patricks Day deals explicitly marketed to people who hate the Irish? It’s not a good analogy because the Irish are people and math is an idea, but it’s pretty odd to focus holiday coverage on people who hate the idea behind the holiday.) USA Today asked us to watch these stunning videos of kids reciting 3.14. The headline is bizarre, but the kids are lovely, and if they enjoy memorizing the digits of pi, good for them. I just wish the coverage had less gawking at non-mathematical activities in it.
Next Pi Day, 3/14/16, is a better approximation of pi than 3/14/15. I guess we’ll be meeting back in a year for another “Pi Day of the century”!