Tracy Hall • 15 years ago
All valid points, and useful criticisms of Pi Day, a day which I somewhat reluctantly endorse just because of the value of anything at all that celebrates mathematics. My main issue with the cult of pi goes deeper, though: we have named and are celebrating the wrong constant. The more fundamental constant is the ratio of circumference to radius, not diameter. This is the form that shows up all over mathematics, and most of the facts about pi in fact make more sense if they are translated to be facts about twopi. It's really unfortunate that Euler gave his imprimatur to a name for the wrong constant, and we're pretty much stuck with the convention now. I count this as as unfortunate a convention as the sign of electrical charge--but Franklin had nothing to go on and Euler should have known better.
Incidentally, that whopper of a number 292 so early in the continued fraction is what accounts for the astonishing accuracy of the approximation 710/113 for the fundamental constant.
I think you're missing the point of memorizing digits of pi. The point isn't for usefulness; it's just a fun challenge. Sort of like collecting milk jugs, but not as easy. Of course isn't useful mathematically to memorize more than a few digits of pi - unless you're testing an algorithm, in which case it might help to have memorized 10 or so digits so you can check your results.
I memorized more than 300 digits not because I thought they would be more useful mathematically than 5 digits, but because it was a fun way to test my memory. I don't celebrate Pi Day, so I didn't memorize for any contests.