Everybody! Happy Pi Day! This is truly a glorious day to celebrate, sadly it often goes by unnoticed and unacknowledged. I never knew about Pi Day until I came to L.A. The first few numbers of Pi are 3.14, which correspond to today’s date in America. Here, the date is written with the month preceding the date i.e. 3.14.17. In Singapore however, the custom is to write it with the day preceding the month, i.e. 14.3.17, which explains why I never knew about Pi day, since there are only 12 (and not 14) months. Thankfully, National Pi Day was brought to my attention exactly two years ago in 3.14.15, which was especially significant because those are exactly the first 6 numbers of Pi!

For this very special day, I intend to celebrate with a post on a delectably tart and crumbly melt-in-your mouth Cranberry Apple Pie that I cobbled together a couple of months ago. But before diving into that, I feel that it is only right to tip my hat towards the very special number we are celebrating today.

What is Pi or rather π ?

π is the ratio of a circle’s circumference to its diameter, it is also an irrational number, meaning that it CANNOT be expressed as a fraction. “But wait,” you may say if you were paying attention in High-school Math Classes, “isn’t π =22/7?”

Interestingly, the fraction 22/7 is only an approximation of the number, as is 3.142, which you may have used in many of your math calculations as a student. The actual value of Pi goes on with no discernible pattern, past the decimal point, all the way to infinity. Because there is no way to reduce Pi to an exact number, the exact value of Pi is inherently unknowable, and it is this nebulous quality about Pi that has intrigued and frustrated Mathematicians throughout history.

If you ever watched the movie “The Life of Pi” you may recall that there was a scene where the main character, Piscine Molitor Patel, in a clever bid to stop his classmates from calling him “Pissing,” declares to his class his new adopted name, “Pi.” He goes up to the board to explain its significance and writes out the number, starting at the top corner with “3.1415…” and going on and on with a sequence of patternless numbers till the board is filled and the school bell rings, and the students start to get ready to rush off to the next class.

However random the number Pi may appear to be, it is anything but random in its actual relevance and use in life.

The number appears everywhere in the natural world where there’s a circle, and can be used to describe natural phenomena in our physical surroundings, such as the disk of the sun, the spherical design of flowers, and the concentric rings that travel outward when a stone hits the surface of a pond. Pi also governs the mysterious inner workings of our own bodies, from the spiral of the DNA double helix, to the pupil of the eye, to the rotation of our elbow joints.

Because of the prevalence of circles and circular movement in all aspects of life, Pi has many practical applications. It is used in modern engineering and math, in the physics of waves, in nuclear research, probability and statistics, in human biology and even in astrophysics! Imagine, without Pi, we wouldn’t have been able to launch the first man into the moon!

Whichever way you cut it, Pi is so much more interesting (and delicious) that what was taught in most of our high-school math classes. I hope this little piece on Pi has inspired you in one way or another.

I will make that promised post on the yummy cranberry apple-pie tomorrow, but for now, here’s a picture of it!