HapPI day!

 

   

Hello Charlie, on this special day, the 14th of march, I wanted to celebrate the day of π!

I have always been fascinated by this constant, and here are some reasons of why this number is absolutely 

incredible:

• Π is infinite with every sequence you want in it, you could find your birthday followed by your parents 

  and siblings, or literally every sequence you can think of.

• Thanks to the incredible pun, you have the right to eat as much pie as you want on that day!

• On this day there are not only people eating pie but also researchers publishing results of studies on 

  this number and more generally as it is a day dedicated to mathematics. 

For instance on the 14th march 2019, the google employee Emma Haruka Iwao calculated pi to a new 

world record length of 31 trillion digits, far past the previous record of 22 trillion.

   

• Because you can tell plenty of jokes about physics (see pictures below) and because there are also plenty 

  of competitions of people learning by heart digits and trying to break the world record officially established at

  70 000 digits in 9 hours and 27 minutes by Rajveer Meena, but there are other unofficial performances 

  with much more digits though it is already incredible to retain that much numbers. During this day the 

  challenge  is to try to learn as many digits as you can and I will show you how to do that.

A picture of the board in my math club at Luminy - but technically it is the math club of the fac of St Charles - and 

on the picture in the right, one of my friends joking about how physics is approximative (I did cross it out afterwards).

I memorized about 150 digits of pi and I’ve got to say it is very practical when you don’t know what to do like in 

the subway, in *coughs* class *coughs* plenty of situations when you are stuck. You can memorize it with poems,

for instance:

Poe, E.: Near a Raven    

Midnights so dreary, tired and weary

Silently pondering volumes extolling all by-now obsolete lore.

During my rather long nap - the weirdest tap!    

An ominous vibrating sound disturbing my chamber's antedoor.

"This", I whispered quietly, "I ignore".

Perfectly, the intellect remembers: the ghostly fires, a glittering ember.

Inflamed by lightning's outbursts, windows cast penumbras upon this floor.

Sorrowful, as one mistreated, unhappy thoughts I heeded:

That inimitable lesson in elegance - Lenore -

Is delighting, exciting...nevermore.

Ominously, curtains parted (my serenity outsmarted),

And fear overcame my being - the fear of "forevermore".

Fearful foreboding abided, selfish sentiment confided,

As I said, "Methinks mysterious traveler knocks afore.

A man is visiting, of age threescore."

(...)

The poem goes on and gives 740 digits of pi. To find the digits, you need to count the letters of each word, for 

example “Poe” is 3 letters so it gives the first digit, then “E” is one, even though they cheated a little bit here… 

And the 0 is when a word is 10 letters long, like “disturbing”. If you want to read the full poem here is the link:

http://www.pi314.net/eng/poemes.php

There are also plenty of other poems like the famous one in french that I learned, just search it online, 

it is the same principle!

Another way to memorize it is a little bit more time consuming at first, as you need to combine two memorization 

techniques, or at least that is the way I do it. You first need a “mind palace” as Sherlock in the series would say ;) 

Unlike the title suggests, it can be wherever you want, a place you know well like your home. And I use it with 

association of images and numbers: each number from 0 to 99 is assigned a mental image because images and 

stories are easier to retain than plenty of numbers. Number 2 is a duck because of the shape it has, or number 11 

is The Thinker by Rodin because it is in bronze, so it is rhyming in French. But these are my associations, 

you have to create yours for it to work. Moreover, it is useful for memorizing information such as dates in 

history or phone numbers. Afterwards, I create a story with the different images in a memory palace and I create 

a story with the different numbers interacting with the next digits.

You can as well download applications that make you learn it, but the risk is to only know it in your muscle memory. 

It is like in music, I can’t tell all the notes written on the score by heart though I can play by memory. Today you can 

test it by searching “pi” in google, and it will start this kind of game.

As we have seen with poetry, pi can be used in art. I like linking mathematics to art because though it is not always 

the case, it is still sometimes like for designers who draw logos using functions, are Bach who was a mathematician 

and used plenty of patterns in his music. A great  example of an artist would be Martin Krzywinski (hopefully I don’t 

have to pronounce it), who uses pi as a base for his creations:

The Art of Martin Krzywinski, associating each number with a color.

 But you can also use Pi in music, by associating numbers with notes or with rhythm and find a theme among 

its digits! Though, you can’t use all the numbers in the order they are in without stopping as it would only make 

a random list of notes with no melody. There is this pianist on youtube that tried to harmonize a part of pi, but I 

think it still sounds random: https://www.youtube.com/watch?v=OMq9he-5HUU

Pi is also amazing because it has been a mystery since the papyrus of Rhind in 1800 BC, and plenty of important 

mathematicians spent their time trying to figure out the way to calculate pi.

Number of digits in function of time

Among them, Archimedes discovered a fundamental way to calculate digits and he is the first one to demonstrate 

his work. He was searching for a way to calculate the area of a circle, and he already knew how to calculate the 

area of a rectangle. So he cut a circle into triangles and assembled them into what resembles a parallelogram 

at first and then a rectangle. The more he cuts the circle into triangles, the more precision. But of course there 

are still small parts left as a circle is not a polygon. He proved by this way that ​223⁄71 < π < ​22⁄7.

Today another good way to understand how to find pi is by this animation showing that for a circle with a diameter 

equal to one, the perimeter was equal to pi:

That is all for today, I hope you enjoyed this article and I wish you a HapPI day!

Astrid