# A constant reminderJuly 23, 2009 4:08 AM   Subscribe

"This day may be celebrated in a variety of ways. Pause and give thought to the role that the number pi has played in your life. Imagine a world without pi. Attempt to memorise pi to as many decimal places as you can. If you're feeling creative, devise alternative values for pi. Go to a party (I will). Or just celebrate in the time-honoured fashion of ignoring Pi Approximation Day altogether."

Happy Pi Approximation Day.

Previously, approximately.
posted by swift (55 comments total) 3 users marked this as a favorite

(Also, my one-hundredth front-page post.)
posted by swift at 4:10 AM on July 23, 2009

Wait, wasn't Pi Approximation Day yesterday? 22/7? (22 / 7 = 3.14285714, 23 / 7 = 3.28571429)
posted by cometwendy at 4:21 AM on July 23, 2009

I thought it was March 14th at 1:59:26 in the morning.

We need to do something about these Orthodox Pitheists.
posted by robocop is bleeding at 4:30 AM on July 23, 2009 [5 favorites]

23/7 is correct to zero decimal places.

My fave is:

π = 4*(1 - 1/3 + 1/5 - 1/7 + 1/9 ...)

I get to celebrate every alternate day of January and April!
posted by DU at 4:30 AM on July 23, 2009 [2 favorites]

Does this mean I missed "So You Think You Can Dance?"
posted by swift at 4:32 AM on July 23, 2009 [1 favorite]

posted by DU at 4:37 AM on July 23, 2009

Are there celebrations at 3:55 and 1:13?
posted by jonp72 at 4:51 AM on July 23, 2009 [1 favorite]

I celebrate Pi Approximation Day on Mar 14 and Pi Day on Jul 22, since 22/7 is closer to π than 3.14 is. Maybe I'll just spend the day being Normal.
posted by Plutor at 4:54 AM on July 23, 2009 [2 favorites]

Every day is π approximation day. Give or take.
posted by Civil_Disobedient at 5:01 AM on July 23, 2009 [3 favorites]

I celebrate Pi Day Approximation Day every year on March 15th. Or close to it.
posted by PlusDistance at 5:07 AM on July 23, 2009

But really, these are all just Hallmark holidays.
posted by PlusDistance at 5:07 AM on July 23, 2009 [4 favorites]

I'm going to bake an approximate pie.
posted by pemberkins at 5:09 AM on July 23, 2009

Oh, I was just telling some people about http://en.wikipedia.org/wiki/Proof_that_22/7_exceeds_π without even realising I'd just missed the day.
posted by edd at 5:12 AM on July 23, 2009

Outside of Card:
Sorry I can't be "a-round" you today

Inside of Card:
But at least this card makes me feel closer!
Happy Pi Approximation Day!

Illustration:
Sandra Boynton drawing of an asymptotic function.
posted by PlusDistance at 5:22 AM on July 23, 2009 [13 favorites]

I just write it as: 10

in base pi, of course
posted by FishBike at 5:40 AM on July 23, 2009 [7 favorites]

You mean pinary?
posted by Plutor at 5:44 AM on July 23, 2009 [8 favorites]

Has Mathematics hired a pr firm? Must everything become advertising fodder? If I blog that the year 1732, when George Washington was born, was celebrated as The Square Root of Three Year you could get your 101st FPP.
posted by Obscure Reference at 5:46 AM on July 23, 2009

I always thought this fellow provided us with an approximation of pie.
posted by Spatch at 5:47 AM on July 23, 2009

7:48 restate my assumptions: 1. Mathematics is the language of nature. 2. Everything around us can be represented and understood through numbers. 3. If you graph these numbers, patterns emerge. Therefore: There are patterns everywhere in nature.
posted by drezdn at 5:47 AM on July 23, 2009 [1 favorite]

There was also agitated discussion about how circles would look, if the ratio of their circumference to their diameter would equal 3.

Viktor's theory was that they'd kind of be oval, all way round. I suggested that they'd look just like ordinary circles, but slightly smaller.

I propose they'd be like ordinary circles, but bigger in the middle. Like a circle with a potbelly.
posted by echo target at 5:54 AM on July 23, 2009 [2 favorites]

i love pies as much as the next guy, but prefer e day 'cause then i have an excuse to take drugs & go dancing.

now, if only pi day was immediately after. like, at 7 in the morning. then i'd love mathematics.
posted by breadfruit at 5:58 AM on July 23, 2009 [1 favorite]

waiting for user # 23881 to weigh in.
posted by brevator at 6:01 AM on July 23, 2009 [1 favorite]

I almost recited the fifty digits of pi that I know at our meetup last weekend. Thank goodness someone stopped me.
posted by greekphilosophy at 6:01 AM on July 23, 2009

I prefer i day, but people are always accusing me of making it up.
posted by Civil_Disobedient at 6:04 AM on July 23, 2009 [12 favorites]

The concept of base pi has broken my brain, which wasn't all that solid to start with.
posted by nax at 6:06 AM on July 23, 2009

πnary is kind of blowing my mind. The circumference of a circle is 20π radians. The area is 10r2. So simple. And yet every integer is transcendental. Or something. I can't even figure out how to count in πnary.
posted by DU at 6:09 AM on July 23, 2009 [2 favorites]

Every day is *sigh* day for me, but I prefer to tell people that I am celebrating Psi Day.
posted by Secret Life of Gravy at 6:09 AM on July 23, 2009

Is this something I'd have to be European to understand?
posted by jpdoane at 6:19 AM on July 23, 2009 [2 favorites]

in base pi, of course

I was considering the logistics of converting Tom Lehrer's "New Math" from base 8 to base pi and I think it gave me a minor stroke.
posted by backseatpilot at 6:41 AM on July 23, 2009 [3 favorites]

Base pi is just like base 8....IF YOU HAVE CIRCULAR HANDS.
posted by DU at 7:05 AM on July 23, 2009 [8 favorites]

What, base pi is simple! It's like any other base. The units digit has the value 1, digits to the left are valued with increasing exponents of pi (pi1, pi2, pi3, and so on). And of course, digits to the right of the decimal point (or is that pi point) are valued with decreasing exponents of pi (pi-1, pi-2, pi-3...).

Makes writing pi easy, but a normal number like 10,000 comes out as 100120100.2102022221 (approximately). Most of the digits will be 0, 1, or 2, but the occasional 3 is also possible.

To steal a line from Tom Duff (inventor of Duff's Device): Disgusting, no?

I imagine anyone with any formal mathematical training is being sick right now.
posted by FishBike at 7:08 AM on July 23, 2009

I'm still hung over from Avogadro's number day.
posted by Balisong at 7:10 AM on July 23, 2009 [1 favorite]

DU FTW

fwiw
posted by grubi at 7:12 AM on July 23, 2009

The units digit has the value 1, digits to the left are valued with increasing exponents of pi (pi1, pi2, pi3, and so on)

I wanted to say that. But then 10-1 > 2. Which...what?
posted by DU at 7:18 AM on July 23, 2009

I wanted to say that. But then 10-1 > 2. Which...what?

Indeed. In base pi, 10 - 1 = 2.0110211100, which is greater than 2 and less than 3, as expected. Isn't it horrible?
posted by FishBike at 7:21 AM on July 23, 2009

Even though it feels a bit irrational, I will nth pi day.
posted by effluvia at 7:31 AM on July 23, 2009 [2 favorites]

It's always fun when pi is 2.
posted by wobh at 7:36 AM on July 23, 2009

I prefer to celebrate my favorite numbers on e + 1 = 0 day.
posted by mathlete at 7:41 AM on July 23, 2009

posted by aniola at 8:00 AM on July 23, 2009

PI IS EXACTLY THREE!

Thank you. Now that I have your attention…
posted by paisley henosis at 8:16 AM on July 23, 2009

I've got a peaceful, e-zy feeling ....
posted by lukemeister at 8:17 AM on July 23, 2009

> PI IS EXACTLY THREE!

Oh no! All circles have become hexagons!

But that's okay, because I really enjoy hexagons.
posted by SteelyDuran at 8:23 AM on July 23, 2009 [1 favorite]

Pinary fits the occasion, but phinary (based on the golden ratio φ) is a bit more useful, especially since you can simplify numbers using the relationship:

φn + φn-1 = φn+1

So you can simplify 11φ → 100φ
posted by Plutor at 8:24 AM on July 23, 2009 [4 favorites]

No, no; cornbread are square. Pie are round.
posted by yhbc at 8:25 AM on July 23, 2009 [2 favorites]

posted by Makoto at 10:11 AM on July 23, 2009

Cobbler is approximately pie.
posted by notashroom at 10:26 AM on July 23, 2009 [2 favorites]

Last year, I had a Pi Approximation Day party where we brought various approximations of pie such as quiche, cobbler, etc. We also played pin the digits on pi.
posted by signalnine at 10:40 AM on July 23, 2009 [1 favorite]

I prefer to celebrate Pi Approximation Month every March.
posted by grateful at 10:41 AM on July 23, 2009 [1 favorite]

Hey, that's my site! I haven't celebrated Pi Approximation Day since 1998, but I did coincidentally eat a really good blueberry pie a couple of days ago, so that should keep the gods of mathematics reasonably calm.
posted by martinrebas at 1:07 PM on July 23, 2009

In base pi, 10 - 1 = 2.0110211100, which is greater than 2 and less than 3, as expected.

I don't think you mean "3". . .

but I'm not smart enough to FTFY
posted by flotson at 8:18 PM on July 23, 2009

Eh. A far more useful version of pinary would be to simply define all usable numbers as being x(real number)*some exponent of pi. So 10 pi + 1 pi = 11 pi, but 10 pi * 1 pi = 10 Pi^2, and 10 pi / 1 pi = 10. I can think of all kinds of applications for that, and you don't need to muck around with the silliness that comes from trying to use a base system designed for integers with a noninteger.
posted by kyrademon at 8:34 PM on July 23, 2009

I feel like these rare 'Pi days' happen about once every 3 months.
posted by iamkimiam at 11:10 PM on July 23, 2009

It's never occurred to me that in day/month ordering my birthday is a pi approximation. I feel like a failure. Maybe I can just blame the weirdness of mixed big- and little-endianness in writing dates.

Only have to wait π×107 seconds for the next one, though!
posted by fantabulous timewaster at 4:43 AM on July 24, 2009 [1 favorite]