Make a joyful noise for today, oh happy day, is Pi Day, 3/14. As you surely know by now, either because you remember *some* maths or because you don’t live in in the wild, 3.14 are the first few digits of π. And, as we know, Pi are squared. Although, as my 8th grade math teacher Louise Blanchfield told us with a mischievous old-lady I’ve-been-telling-this-joke-for-forty-years grin, “Pi are not squared, Pi are round.” Meanwhile, I am proud to say that the establishment of this august day of celebration first occurred in my neck of woods, a day recognized by Larry Shaw at the San Francisco Exploratorium back in 1988. The rest is a lot of fun history.

## Achtung Lieber! It’s a Miracle!

One particularly curious fact about Pi Day is that it also happens to be Albert Einstein’s birthday. He didn’t have anything to say about pi, *pier se* (see what I did there? that’s not the last pun I am about to inflict on you either)… anyway, Einstein wasn’t a geometer, but he was a brainy guy and did a lot of math. Actually he failed math, which is always used as an example of how you could buckle down and make something of yourself even if you start a failure.

However, I always thought it was a better example of how to successfully buck the establishment, since it’s likely that Einstein failed math because he kept telling the teachers they were wrong. And they were. It’s more like Stephen Hawking crumpling up his physics homework and throwing it in the trash because he didn’t think his proofs were elegant enough. Other students would get them out of the trash so they could understand how to do physics.

RIP Stephen Hawking–who coincidentally passed away yesterday–or maybe it was today since it’s 12 hours ahead in Cambridge. (And you know those smart people always want to be ahead of everybody else.) Stephen and Albert can now argue about the exact shape of the curvature of space-time until infinity or until the end of pi. Maybe they can borrow some of Newton’s apples to use for examples.

Guck mal, Schatzi – der ist am Pi-Tag geboren!

–Einstein’s mother

## The Miracle of Pi

Pi is a shorthand definition for the ratio of a circle’s circumference to its diameter, which stays the same no matter how big or small the circle gets. On the one hand, that seems like an amazing fact, a miracle of nature like the Golden Ratio or that ontogeny recapitulates phylogeny. On the other hand, it reminds me of the Monty Python skit where the scientist says, “If you enlarge a penguin to be the size of a human, its brain would still be smaller than a human brain, BUT–and this is the important point–the brain would be much larger than it was!”

Pi is an irrational number, which means it’s better if you don’t give it too much to drink or get it started discussing politics. It’s notoriously hard to calculate. This British dude, Wiliam Shanks, apparently spent 15 years calculating the first seven hundred digits by hand (or with an abacus or slide rule or whatever they used in 1840) but unfortunately he made a mistake at digit 528.

Mathematicians have been trying to create the right definition or series to represent pi since the Egyptians started wearing funny hats. Historians note that the Great Pyramid at Giza seems to be built in a ratio very similar to pi, so it might have originally been called a pi-ramid.

Another weird fact about pi involves the ancient city of Carthage, which is that place that brought all the elephants into Italy. There were 22 of them going down 7 mountains, and they still haven’t forgotten about that. Wikipedia points out that Lord Kelvin told this story about Queen Dido working on what’s come to be called the isoperimetric problem. She was trying to figure out how to enclose the lands bordering the sea for her new city, “using a single given oxhide, cut into strips.” As the legend goes, Aeneas came along, seduced her, and stole her treasures, which caused Dido to commit suicide by throwing herself onto a pyre. (*Or was that a pi-re?*) (*Hey, I told you I’d leave no pun unturned.)*

And so an ungrateful and unreceptive man with a rigid mind caused the loss of a potential mathematician. This was the first blow to mathematics which the Romans dealt.

–Morris Kline,Mathematics for the Nonmathematician

The Greeks went on to show that a circle would have enclosed a greater area than any polygon with the same perimeter, so Dido was avenged by pi. Pi says, *you’re welcome.*

Euler started using the Greek letter π, to refer to this ratio about the perimeter of a circle. Every time I hear his name, I hear Ben Stein as the teacher taking attendance in that droning voice, “*Euler? Euler?*”

## How Many Digits of Pi Does it Take to Screw in a Lightbulb?

Once computers started getting in the act of calculating digits of pi, the ENIAC calculated 2037 digits using an arctan series. The arc of the tangent is kind of like the Ark of the Covenant because it holds the mysteries of the universe, though Steven Spielberg did not make a movie about it.

New records keep going to set digits of pi, using Eigen values, Fourier transformations, and Gaussian integrals. I mean, everybody knows how integral the Gaussian is. The one place you never want to get hit is in the Gaussian. Memorizing digits of pi, too, is very popular. According to the *Guinness Book of World Records*, Rajveer Meena recited pi to 70,000 in 2015.

The question about all this furious calculating and memorizing might be * Why*? If you’re at 5 trillion now, would it be better to get to 5 trillion and 3, or 5 trillion and 3.14? This seems like breaking the record for eating hot dogs. After 50 dogs, man, just stop!

## Fun facts about Pi Day

The site piday.org lists a plethora of fun happenings that occur around the world on pi day. Which is a little curious, since as we know from looking at world religions and history, many other cultures use different calendar systems that don’t generate the number 3.14. Today on the Jewish calendar is the 27th of Nadar in 5778 which sounds impressive but doesn’t have the same ring to it (ring! get it?).

Many events will take place which involve the reading of the digits. I work for an educational company which hosts an annual event on Skype where they read the first 100 digits. I’m sure it’s a riveting spectacle. MIT sends out its acceptance emails today, by tradition, so geeky teenagers all over the country will be letting out whoops of joy. *Runner’s World* suggests people run 3.14 miles, kilometers, blocks, or circles around their house. I’m opting to just run rings around the logic of pie.

## The Miracle of Pie

The other fun thing to do on pi day is, of course, to eat pie. Any kind of pie! Gooseberry pie, pizza pie, banana cream pie, steak and cheddar pie, shepherd’s pie… My wife loves shepherd’s pie, but we had some at an Irish pub the other night which had the effrontery to replace most of the mashed potatoes with cheese. The nerve! I’m still hearing about it.

The secret to a really good, flaky pie crust is the way that the butter or shortening is cut into the flour. The fat should be laid in little thickets; pea-sized would be too small and would make the crust mealy, not flaky. The fat– and there is a large debate about butter vs. shortening, but no debate about the rectangularization of the fat–should have enough size that it might even be visible blocks in the crust. When it heats in the oven, it will melt and evaporate into steam. The steam will create an air pocket in the crust. Voila! Le Flake!

As for pizza dough, one of the keys to getting a crispy enough crust on the outside is to gently brush the dough with a little olive oil before adding the toppings. Use high heat–one guide calls for over 500 degrees–to get enough crisp. Then, you can cut the pizza into either six or eight slices. It depends on whether you’re hungry enough to eat all eight; if not, just cut it into six.

## All Part of the Great Cosmic Unconsciousness

Pi has come to be revered as part of the great cosmic unconsciousness, one of the mysteries of the universe. Given how many cultures have wrestled with its formulation and calculation, pi has a certain stature across the ages.

Consider that 3.14 written in mirror script spells P-I-E, and you can buy a T-shirt here that proves it. Now leet, also known as 1337, is a system of symbolic spelling and verbiage used by the mysticians on the internets, also known as nerds. They have carefully pointed out also that:

Pi x 1337%=42

–the internets

For those who are not leet-savvy, 42 is the answer to everything.

Now, I just can’t wait for 10/23, which is Mole Day.