# 3.14.15 Is Pie Day

Illustration by Ryan Miller.

March fourteenth, two thousand fifteen is pie day … an apple, a pear, a plum, a cherry, anything to make us all merry. March 14, 2015 expressed as 3.1415 is pi, or π.

The number is said to be infinite, expressed as a fraction 22/7 or 223/71, both work well enough. The Path of the Beagle site says “pi is infinite and non-repeating,” currently calculated to 10 trillion places. The author of the site comments in that string of digits is the name of every person who ever lived, as well as the date and manner of their death. There is something a touch eerie about pi.

The illustration demonstrated precisely what a math geek is good for. To point out gene sequences do well enough with just four variables, A, C, G, T, to the gain of every species on earth.

Despite pi is calculated to 10 trillion places we really need only 39. The diameter of the known universe is 8.8 x 10 26 meters, multiply by pi yields a circumference of only 39 digits. So why do people who ought have better things to do figure pi to 10 trillion places?

Archimedes, that old white guy, is credited with the creation of the ratio of the diameter to the circumference, what we call pi. A standing argument exists, whether the Greek letter stands for periphery or perimeter, the 16th letter of the 24 character Greek alphabet.

Archimedes gets the classroom credit for pi because he is the most convenient geek to hang the blame on despite pi as a construction concept was known in both Babylon and Egypt 4,000 years ago. If perhaps to wonder why we follow the precepts of a tribe as didn’t do math, didn’t do pyramids, or libraries, or pi, and who simplified the Godhead to a monopolistic corporation instead of a lousy intrigue-filled ugly rabble of gods who acted pretty human including the fist fights and sex. If they also allowed women their fair share of time on the throne.

In Babylon is a clay tablet dated to 1600 B.C. that treats pi as the fraction of 25/8. The pyramid at Giza, circa 2589-2566 B.C., took 23 years to build, has a perimeter of 1760 cubits, a height of 280 cubits, the ratio of 1760/280 equals 6.2857 or 2 π. This may be pure coincidence or it might be some worshipful recognition of that number. Or just plain creepy.

An Egyptian scribe, that we yet know the name of, Ahmes, produced a three-volume papyrus in which he sits down an “Accurate reckoning for inquiring into things and the knowledge of all things, mysteries and secrets.” In the first volume he explores number theory such as 2/15 = 1/10 + 1/30. Again creepy. That 2/101 = 1/101 + 1/202 + 1/303 + 1/606, all in all enough to give most people a headache as explains math geeks.

His second volume explores volume of granary storage, to suspect this bit of math played an important role in the marketplace forces of the Valley of the Nile, to calculate the volume of grain silos.

V = [(1 – 1/9) d 2 ] h

Expressed in more modern notation

Volume = (8/9) d2 h = (256/81 r2 h)

256/81 equals 3.1605, or pi close enough. Circa 2500 and change BC.

In volume three, Ahmes continues his computations involving bread and beer and how much feed is necessary for fowl and oxen. Feed to weight-gain efficiency, not so geeky. Sounding like any modern Extension researcher.

March 14, 2015 celebrates the once-in-a-century occurrence of 3.1415. There is one little problem with pi day … it’s wrong. Since the next digit is a nine, 3.1416 is closer than 3.1415. But the popular die has been cast, 3.1415 is designated pi day. To think celebrating pi, or π, or pie, or Archimedes, or ancient Babylon isn’t such a bad thing to do.

So go celebrate pie day, the choice is yours, “an apple, a pear, a plum, a cherry, anything to make us all merry.”