Dear reader, it's the fourteenth day of the third month of the year, and if you're reading this blog, some charlatans or overenthusiastic youth (the subject of whose enthusiasm is not what they think it is) have probably tried to convince you to celebrate it as "Pi Day." You see (these quacks implored you) π is around 3.14, and March fourteenth is 3/14. And furthermore (they may have put to you) furthermore this year's Pi Day is special, because it's 3/14/15, which is like 3.1415! Why (an especially impudent few might have continued to venture), we should plan some grand spectacle on 9:26 a.m. on the day, which is like 3.1415926! With (and this is the part that is most inevitable and offensive) pie! Get it, because it sounds like pi and is shaped like a circle?
Dear reader, it is lies or it is worse than lies; it is blasphemy, treason, superstitious superficiality, degenerate folderol, and frivolous depravity! Do not mistake me; of course I can see as clearly as any other ape can that the numeric subsequence of the string "3.14" is same as that of the string "3/14". The former string represents an occasionally useful approximation of the circle constant which is ubiquitous in mathematics (give or take a factor of two); the latter is how people in my country abbreviate today's date. Perhaps to those who don't have anything really interesting to think about, this trivial coincidence might be worth a passing mention; apes love anything for an innocent distraction, and why begrudge that?
What is intolerable, however, is for a mathematically meaningless coincidence to be marketed as a day to celebrate mathematics, which marketing can only propagate the cruel slander that mathematics is about memorizing and manipulating figures. Not that seekers of true mathematical knowledge don't have occasion to manipulate figures from time to time—we do—but we do it because the figures actually mean something. And the similarity between the decimal number "3.14" and the date "3/14" ... doesn't really mean anything. Our dominant culture happens to prefer a base-ten place-value system, in which the representation of the quantity π happens to start with 3.14. That means: three (times ten-to-the-zeroth), plus one-tenth (which is one times ten-to-the-negative-first), plus four one-hundredths (which is four times ten-to-the-negative-second), plus other terms that our to-two-decimal-places approximation neglects. Whereas 3/14 means: the fourteenth day of the third month. It's not the same number as 3.14, even if its standard representation happens to involve the same digits in the same order.
If there must be a Pi Day, I can imagine sensible arguments for holding it once every three years and fifty-two days (around π years), or on January fourth at 3:23 a.m. (about π days into the new year), or on one of the solstices or equinoxes (when the Earth is π radians around the sun from some imagined "zero" at the opposite solstice or equinox).
But March fourteenth? What is wrong with the world such that such a travesty could gain common currency? Can't our innocent distractions at least rise to making a pretense of meaning something? Don't our cultural symbols deserve to have semantics deeper than mere empty tokens that can only be recognized, compared, and gawked at?
For the children.