Today is pi day, 3/14. You know, pi, the irrational number, 3.141592654… We all learned the basic formulas for a circle involving pi in school:
- (circumference equals pi times diameter)
- (area = pi times the radius squared)
OK, no more formulas. I promise. With today’s computers, the value of pi has been calculated to millions of decimal places. However, not so long ago, the computations had to be made by hand, and it was a lot more difficult to determine the value of pi. The history of pi is one of progressive refinement:
- The Babylonians initially calculated pi to the not-very-precise value of 3.
- The Egyptians used a value of 22/7.
- And in the 5th century, the Chinese mathematician , Zu Chongzhi, determined pi to be 355/113. This last value was within 8.5 millionths of a percent of the now-known value of pi! Not bad for a guy with pencil and paper.
There are many websites devoted to pi, so I will not repeat all their information here. To get started with your pi learning, I would suggest www.exploratorium.edu. For even more information about pi, you can go to www.pi314.net.
Pi is not reserved for only the mathematicians. Pi has also been explored by musicians. Here is a fun, creative musical pi video:
So, how are you planning to celebrate pi day? Let me know. And me? What am I planning for my pi day celebration? I think I will have a piece of pie.