If you’ve ever wanted to memorise the first nine digits of pi then you’re in luck. Inkycircus points to a video by Hard ‘n’ Phirm extolling the joys of pi. There’s even a rap bit which tells you how to memorise them backwards if you live in Quebec.

When ink and pen in hands of men inscribe your form bipedally,

They draw an altar on which God has slaughtered all stability.

No eyes could ever soak in all the places you anoint,

And yet to see you all at once we only need the point.

Flirting with infinity, your geometric progeny,

That fit inside you oh so tight,

With triangles that feel so right.

3.14159265358979323846264338327950288419716939937510582097494459Your ever-constant homily says flaw is discipline.

The patron saint of imperfection frees us from our sin,

And if our transcendental lift shall find a final floor,

Then Man will know the death of God where wonder was before.

…and then because there’s a rap that’s where the pi-related swearing starts.

It’s poetry. You can tell it’s poetry because it rhymes which is nine-tenths of poetry as far as I’m concerned. When I finally get round to reading Stephen Fry’s Ode Less Travelled I might have a more intelligent opinion on poetry, but for now I’ll stick with my stupid one. The song closes with over 170 digits of pi, so if you memorise the lyrics you’ll have all the pi you need.

The Wikipedia entry on Piphilology has this nice poem:

Sir, I send a rhyme excelling,

in sacred truth and rigid spelling,

numerical sprites elucidate,

for me the lexicon’s dull weight.

which encodes the first twenty-one digits. But that’s no help if you want to memorise pi backwards.

Because pi is an irrational number you can find any finite sequence of numbers in it if you look hard enough. You can (probably) find your birthday in the first 200 million digits of pi.

The thing that bothered me in school is that pi is the ratio of a circle’s circumference to its diameter. So how do you calculate pi accurately? You simply cannot measure a circle accurately enough (if you could find a perfect circle). If the Earth’s orbit were perfectly circular and you could measure it to millimetre accuracy you still wouldn’t reach twenty decimal places. So where do you get 200 million from? Mathworld gives you various ways to calculate it.