# PI DAY 2018: Think You Know Everything About Pi? Think Again …

It’s that time again. Today is March 14, the day hordes of math geeks everywhere celebrate Pi Day 2018. They go to pie-eating parties, they dance around Pi sculptures and they wear Pi beads to help them remember the seemingly endless irrational number.

And if they get good at that, they up the ante by entering day-long Pi recitation competitions. I can’t think of a better way to spend 10 hours, can you?

Click to enlarge

As insanely fun as that must be, I use the occasion every year to share obscure Pi trivia and Pi history facts with Pi lovers everywhere. This year, I’m also out to clear up the huge amounts of disinformation around that infinite number you get when you calculate the ration between any circle’s circumference and its diameter.

Hey, one can only take so much fake news …

But you already know everything about Pi, you say? Okay. Maybe you among the few folks around who know that the irrational number once called Archimedes’ number wasn’t invented by Archimedes at all. Archimedes merely named the number after himself and popularized it. The Babylonians, the Egyptians and even the Bible mention 3.14159.. centuries before that ancient Greek was even born sometime around 280 BC.

And perhaps you’re one of the few people around who know that it was William Jones of Wales (no known relation to Wikipedia founder Jimmy Wales) was the one to give Pi its name back in 1706. And you might also know that March 14 is both Pi Day and Albert Einstein’s birthday. Sadly, it is also now the day that Stephen Hawking passed away.

Haven’t stumped you yet? Well, read on. Following is some of my favorite obscure Pi triviata and factoids.  Enjoy.
And happy Pi Day 2018 from all of us here at the Heidelberg Laureate forum. Enjoy!

• Pi is usually described as the ratio of a computer’s circumference to its diameter, as mentioned above. But there’s another way to describe Pi: It’s the  number of times the diameter of a circle will fit around is circumference.
• Pi is an irrational number that is, apparently, infinite. It just keeps going and going, with no repeating series of numbers. Yet, anyway. It’s been calculated to well over a trillion places with no end in sight.
• Calculating Pi is cool, but not nearly as cool as the subculture of Pi fans worldwide who’ve made a sport out of memorizing and reciting it. Did you know there are actually clubs people join where they practice doing this?
• Japanese student, Kiroyuki Gotu, once recited Pi to 42,195 places (from memory!) during a Pi competition at the NHK Broadcasting Center in Tokyo. It took Gotu 112 hours to do it, and the crowd was with him all the way, going nuts. I saw it was great. Don’t get it? Maybe you just had to be there …
• Here’s a useful application for Pi you may not know. You can use it to figure out your hat size. Seriously! Measure the circumference around your head and divide it by Pi. Round off the result to an eighth of an inch and Bingo, you’ve got your hat size.
• And you never know if you’ll someday be asked to estimate the height of an elephant, do you? Well, Pi is what you’ll need to meet that challenge. First, measure the diameter of its foot and multiply that number by two. Then take that result and multiply the result by Pi. All your elephant keeper friends will be blown away. Trust me.
• As you might expect, a number that goes on as long and apparently as randomly as Pi is bound to lead to all kinds of conspiracy theories. And it has. There are entire sites online that are so inclined. Some let you convert pi into images, audio files and even alphabetic sequences that spell out messages. But never fear: The Satanical signature 666 doesn’t make an appearance until position 2240. Whew.
• My favorite Pi memorization trick? Try singing the line “Pi, Pi, three point one four one five ” to the tune of Don McLean’s 1970s hit, “Bye, Bye. American Pie.” Some kids in CA came up with this brilliant Pi version of the tune in 1999, right before the very first Pi Day was celebrated in San Francisco at its famed Exploratorium. They wrote a whole song to the tune, and they dedicated it to the day their “math team tied” as opposed to “the day the music died.” Watch it below.
• Math is beautiful, of course, but the peculiar beauty of Pi is most evident in its innate flexibility. You can find Pi in harmonic motion theory, superstring calculations, Einstein’s gravitational field equation and countless other key calculations and formulas. You’ve got to love that.
• Speaking of Pi songs, here’s one right here: It’s a song that was created by matching all the digits in the Pi string to individual notes. In other words, it’s the sound of Pi! Awesome.
• And I love this. Created just for Pi Day, it’s the Pi Domino Spiral. See if you are able to solve its many hidden references. Watch below.
• Would you believe you can calculate a circle the size of the entire universe (down to a proton) using Pi to just 39 places? It’s true.

Can you honestly say you knew all the Pi trivia and strange facts above? If so, we salute you.

Either way, have a terrific Pi Day 2018. Don’t party too hard. It’s a week night! And please, have some Pi for me …

Reporting from Hong Kong for HLF, I’m Gina Smith.

Infographic: San Francisco Exploratorium
https://www.exploratorium.edu/pi/pi-day-history

Cover art: Timothy Edward Downs for aNewDomain

### Posted by Gina Smith

Gina Smith is an award-winning journalist and the New York Times bestselling author of Apple founder Steve Wozniak's biography, iWOZ: How I Invented the Personal Computer and Had Fun Doing It (2006/2014, WW Norton) and The Genomics Age (2005/2015, Amacom), a Barron's book of the year. She holds a brand new PhD in cognitive psychology.

### 2 comments Write a comment

1. Pi’s decimal is infinite because using the circumference of a ‘solid’ object and it’s diameter would encounter measuring down to the atomic level and the electron orbits are always changing.

• Wrong.