Once a year, nerds of the world unite in celebration of a positively exponential occasion. Pi Day is the coming together of two events. When written as 3.14, the date becomes the most celebrated digits of all, pi. The day also marks the birthday of the most influential figure in all of modern physics, Albert Einstein. We’ve gathered just a few facts about these two icons to keep in mind while geeking out.

Pi is an irrational number that represents the ratio of a circle’s circumference. The funny thing is, we can never calculate the true value of pi. No matter the size of a circle, there is no way of accurately calculating its circumference.

The conscious existence of pi is just as infinite as the number itself. While it may not have been known as “pi,” ancient civilizations such as the Babylonians or ancient Egyptians worked with such concepts.

The symbol π originates from an abbreviation of the Greek word *perimetros*, which loosely translates to “circumference.”

Pi is infinite and all encompassing so any grouping of numbers, your phone number for example, is, at some point, in this ongoing generation of digits and appears numerous times.

Piphilology is the practice of recalling the digits of pi using mnemonic techniques.

Ever looked at the digits 3.14 backwards? It looks like the word “PIE.”

In mapping unexplored worlds, scientists use pi in the formula for surface area to determine the number of images it will take to map a planet or celestial body.

Scientists use pi to search for other planets that orbit another star other than the Sun.

In Carl Sagan’s book *Contact, *scientists dig deep into the mystery of the number pi to unearth and unlock the cryptic messages from mankind’s creator.

Pi Day has been the date of a few notable happenings. Not only was Einstein born on 3.14 in 1879, so was Apollo 8 astronaut Frank Borman in 1928. The world also lost beloved physicist Stephen Hawking on this day in 2018.

This Pi Day, celebrate with pi-themed crafts of your own. Use the irrational number as a guideline for art or create a personalized version of a pi pie. The options are just as limitless as pi itself!