If you woke up this morning and saw today’s date, you probably already know: It’s Pi Day! Not the tasty pie with an ‘e’ but the elegant mathematical constant that has the same first three digits as today’s date (3/14).

Here at Julianna Rae, we love pi day.

Yes, it does help that it sounds like we are talking about that wonderful baked goodness of fruit or cream in some kind of pastry shell… But it’s mainly a reminder of  beauty and discovery in its many forms. However you enjoy the day, pi deserves a lot of respect.

The circles, big and small

Pi is defined as the ratio of the circumference of a circle to its diameter. Whether the circle is the size of a pin or our planet, if you lay a piece of string along the circle’s diameter then tie together slightly more than three pieces of that string (approximately 3.14 pieces) you will know the distance around the circle. Of course that’s an estimate because pi keeps going and going and going.

In math, the term “irrational” means there’s no known ending in site and no recognizable pattern. That’s pi. (Now you see where the common meaning of “irrational” gets its roots!). For a few thousand years, when math was done by longhand or by an abacus, pi was calculated as 3, or about 3. Today, computers can spit out trillions of digits of pi. Yet there’s always one more number beyond what is calculated. And no one knows what that will be. So cool, right? It’s irrational and infinite. Here is pi’s numerical value to a few hundred digits (in case you’re ever asked at a dinner party!):

3.141592653589793238462643383279502884197169399375105820974944592307816406286208998628034825342117067982148086513282306647093844609550582231725359408128481117450284102701938521105559644622948954930381964428810975665933446128475648233786783165271201909145648566923460348610454326648213393607260249141273724587006606315588

From waves to eyes

If you’re like most people, you probably learned about pi at school and don’t give it a lot of regular thought. Yet it is a part of your everyday life. Pi is used in almost all scientific and mathematical fields, from engineering to understanding how rivers flow. Everywhere there’s a circle or near circle, pi can help understand it. Mathematicians have used pi in equations that help explain everything from atoms and waves to electronics and even nature, itself. Petals, our eyes, planets, the oceans, sound waves – all owe an understanding to pi.

Pi has fascinated the human race for so long it’s no surprise that artists have worked to translate its beauty. Here is one visualization of pi’s first 1,000 digits by artist Cristian Ilies Vasile, and you can see a few other amazing images on this blog about science.

Want to celebrate Pi Day?

Here’s something to read about a few impressive women mathematicians who often get lost in the history books:

and a fascinating profile at The Guardian of the self-taught mathematician, William Jones, who first used the Greek pi symbol.

And, lest you think there’s still no reason for you to pay attention to pi, here’s eight free or discount pi-related deals put together by Parade magazine! Enjoy!

Share with us when you first learned abut pi or drew your first pi symbol!