Happy π Day

Happy π Day

Two significant events occur on March 14 this year. The first is the release of the “Veronica Mars” movie. The second is the annual celebration of PI (or π) Day!

Yes, PI Day — the geekiest of all the observed holidays. This is the day we get to reflect and pontificate on all things PI.

PI, of course, is the most well known of the mathematical constants — the circumference of a circle divided by its diameter. No matter how large the circle, this ratio remains constant. The first few digits of PI is 3.14, hence the celebration on March 14 (3/14). PI is a fundamental numerical constant in our universe, and the value regularly appears in mathematical models for physics, electronics, statistics and, yes, even rocket science. 

Here are some quick facts about the number PI:

PI is an irrational number. This means that PI cannot be expressed as a fraction of one integer divided by another integer. Since it cannot be expressed as a ratio of integers, the decimal representation of PI requires an infinite number of digits.

It is speculated that the ancient Egyptians were knowledgeable of PI. The Great Pyramid of Giza (constructed around 2600 BC) had a perimeter to height ratio of 6.2857. This ratio is approximately equal to two PI, or 6.2832.

The earliest written approximations of PI date about 1900 BC — 1600 BC from Egypt and Babylon. They both got the first two digits correct.

The earliest use of the Greek symbol to represent PI is by William Jones in 1706. Widespread adoption of the symbol began when the preeminent mathematician Leonhard Euler published Mechanica in 1736.

Modern PI Day celebrations began in 1988 at the San Francisco Exploratorium. The event was organized by Larry Shaw and involved marching around one of the circular spaces and eating fruit pies.

A popular approximation of PI is 22/7, and, in the geekiest of groups, July 22 is celebrated as Approximate PI Day.

Just for reference, the first 100 digits of PI are: 3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679.

My first recollection of the true meaning of PI is my Evans High School trigonometry class. While Mr. Johnson is most renowned for his rendition of the Pythagorean theorem, I vividly remember him marching around the unit circle. As we all know, PI is an integral part of the unit circle. I find the symmetry and elegance of the structure most soothing. PI over 6, PI over 4, PI over 3, PI over 2, and so on. The mathematical equivalent of rinse, lather and repeat. If only more things in life would behave like the unit circle.

In celebration of PI Day this year, I plan to have a busy day. First of all, I’m going awake early and go on a PI-mile run. Every meal will include some sort of pie. Breakfast will be the sausage breakfast pie from the Betty Crocker website; lunch will involve either apple pie or chocolate pie (haven’t decided which yet); and dinner will be a homemade pizza pie. I’ve ordered a unit circle clock for my office, and at 3/14 1:59 p.m. (3.14159), we will observe PI Day by reciting Euler’s Identity.

Finally, my wife and I will finish the day by going to the “Veronica Mars” movie… which is, of course, totally unrelated to PI. However, if the VM movie weren’t playing, we would sit home and watch the movie π.

Tweet us some pictures on how you are celebrating PI Day! 


Until next time, I’m off the grid @gregory_a_baker.

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