Celebrate Pi Day!
What is Pi Day? The holiday honors a special number: "Pi," which is pronounced just like "pie". Pi is an infinite, non-repeating decimal, so it's usually abbreviated to 3.14, hence we celebrate it on March 14! Mathematics represents pi with this symbol: $\pi$.
What does the number mean? For every circle, its distance around (circumference) is always a little more than three times its widest distance across (diameter). When you divide the circumference by the diameter, you get this fascinating number that has no end: 3.1415926535897932384... Indeed, computers have calculated pi to 105 trillion places (and counting) and have found no repeating sequences. As the ratio of a circle's circumference to its diameter, $\pi$ is irrational and transcendental—qualities sure to bring a twinkle to any mathematician's eyes.
How do people celebrate Pi Day?
- The International Day of Mathematics (IDM) is a world-wide celebration led by the International Mathematical Union. You can find a collection of talks and activities in many languages.
- Who came up with Pi Day? Learn about the day's history.
- Many composers have written music inspired by $\pi$. Noam Elkies, a mathematician, composed "Steganographic Étude #1," (PDF) based on the first 244 digits of $\pi$. Read about it.
- Take Math to Mars and Beyond with NASA's 2021 Pi Day Challenge.
- The Exploratorium in San Francisco hosts events every year.
- Google had a special doodle in 2010
- College and university math departments often have pies featuring Pi!
- The AMS bookstore will have a special sale on March 14.
However you celebrate, we hope you enjoy Pi Day!
Top image of 1,000 decimals of Pi by Carlos Francisco Cruz Fierro, CC0, via Wikimedia Commons
Lower image by Shisma, CC BY 4.0