Learning Digitally

March 2009 may well be remembered as one of mathematician’s all time-favorites. First we celebrated Square Root Day March 3rd, and today, March 14, take time we take time to celebrate perhaps one of the universe’s most famous numbers on National Pi Day

Defined as the ratio of circle’s circumference to its diameter, what I like about Pi is that it’s dependable; no matter the size of the circle, the value of Pi is constant, 3.1415926535 when rounded to 10 places.

But for mathematician’s Pi is also a very frustrating and obstinate number. Pi may be dependable when comparing circumferences and diameters, it can be irrational and transcendental. (Perhaps it was Pi’s transcendental nature that led to another age old truth, that you can’t fit a square peg into a round hole!)

Why does Pi deserve it’s own day each year? Because since the time of Archimedes, mathematicians have yet to find an end to Pi. It’s irrational nature stubbornly refuses to allow for the decimal value to repeat or come to an end. (Would you like to see what Pi looks like worked out to the first 10,000 digits? How about a million places?) But let’s not forget that it was Pi’s trillion digit length that allowed us to measure the size of the Earth to within a millimeter of accuracy and has kept programmers and their super computers busy for decades.

So if you are feeling in a celebratory mood may I suggest that today, 3/14 at 1:59pm (the next three numbers in Pi) you share a piece of pie with your favorite math teacher. Perhaps you might like to bring them a Pi necklace that you made yourself.  If you’re in San Francisco stop by the Exploratorium’s 21st annual celebration. And don’t forget wish Albert Einstein a Happy 130th Birthday; isn’t that a cool coincidence!

If you missed today’s celebration, don’t worry. You can celebrate Pi’s fraction approximation on July 22 (22/7) or the 314th day of the year on November 10th. Will the celebrating never end?