Piphilology


Piphilology comprises the creation and use of mnemonic techniques to remember a span of digits of the mathematical constant pi|. The word is a play on the word "pi" itself and of the linguistic field of philology.
There are many ways to memorize, including the use of piems, which are poems that represent in a way such that the length of each word represents a digit. Here is an example of a piem: "Now I need a drink, alcoholic of course, after the heavy lectures involving quantum mechanics." Notice how the first word has three letters, the second word has one, the third has four, the fourth has one, the fifth has five, and so on. In longer examples, 10-letter words are used to represent the digit zero, and this rule is extended to handle repeated digits in so-called Pilish writing. The short story "Cadaeic Cadenza" records the first 3834 digits of in this manner, and a 10,000-word novel, Not A Wake, has been written accordingly.
However, poems prove to be inefficient for large memorizations of. Other methods include remembering patterns in the numbers and the method of loci.

History

Until the 20th century, the number of digits of pi which mathematicians had the stamina to calculate by hand remained in the hundreds, so that memorization of all known digits at the time was possible. In 1949 a computer was used to calculate π to 2000 places, presenting one of the earliest opportunities for a more difficult challenge.
Later computers calculated pi to extraordinary numbers of digits, and people began memorizing more and more of the output. The world record for the number of digits memorized has exploded since the mid-1990s, and it stood at 100,000 as of October 2006. The previous record was set by the same person on July 2, 2005, and the record previous to that was held by Hiroyuki Goto.
An institution from Germany provides the details of the "Pi World Ranking".

Examples in English

The most common mnemonic technique is to memorize a so-called "piem" in which the number of letters in each word is equal to the corresponding digit of π. This famous example for 15 digits has several variations, including:
Short mnemonics such as these, of course, do not take one very far down π's infinite road. Instead, they are intended more as amusing doggerel. If even less accuracy suffices, the following examples can be used:
This second one gives the value of π as 3.1415926535, while the first only brings it to the second five. Indeed, many published poems use truncation instead of one of the several roundings, thereby producing a less-accurate result when the first omitted digit is greater than or equal to five. It is advantageous to use truncation in memorizing if the individual intends to study more places later on, otherwise one will be remembering erroneous digits.
Another mnemonic is:
In this mnemonic the word "point" represents the decimal point itself.
Yet another example is:
In this example, the spelling of Archimedes is normalised to nine.
Longer mnemonics employ the same concept. This example created by Peter M. Brigham incorporates twenty decimal digits:

Poems

Some mnemonics, such as this poem which gives the three and the first 20 decimal digits, use the separation of the poem's title and main body to represent the decimal point:
Another, more poetic version is:
Extensions to 30 or 31 decimals of the same proceed as follows:
There are minor variations on the above rhyme, which still allow pi to be worked out correctly. However, one variation replaces the word "lexicon's" with "lesson's" and in doing so, incorrectly indicates that the 18th digit is seven.
The logologist Dmitri Borgmann gives the following 30-word poem in his book, :
In the fantasy book, Somewhen by David Saul, a 35-word piem both provides a description of the constant pi and the digits. The text is also laid out as a circle to provide another clue to the readers as to the purpose of the poem. In this example, the word "nothing" is used to represent the digit zero.


The following sonnet is a mnemonic for pi to 75 decimal places in iambic pentameter:
Note that in this example, 10-letter words are used to represent the digit zero.
Other poems use sound as a mnemonic technique, as in the following poem which rhymes with the first 140 decimal places of pi using a blend of assonance, slant rhyme, and perfect rhyme:
Note that "dreams number us like pi" corresponds to "314159," and so on. Sound-based mnemonic techniques, unlike pilish, do not require that the letters in each word be counted in order to recall the digits of pi. However, where sound-based mnemonics use assonance, extra care must be taken to distinguish "nine" and "five," which contain the same vowel sound. In this example, the author assumes the convention that zero is often called "O."

Piku

The piku follows the rules of conventional haiku, but with the added mnemonic trick that each word contains the same number of letters as the numerals of pi, e.g.

Songs

In 2004, Andrew Huang wrote a song that was a mnemonic for the first fifty digits of pi, titled "I am the first 50 digits of pi". The first line is:
In 2013, Huang extended the song to include the first 100 digits of pi, and changed the title to "Pi Mnemonic Song".

Lengthier works

There are piphilologists who have written texts that encode hundreds or thousands of digits. This is an example of constrained writing, known as "Pilish". For example, Poe, E.: Near a Raven represents 740 digits, Cadaeic Cadenza encodes 3835, and Not A Wake extends to 10,000 digits.

Sound-based mnemonics

It is also possible to use the rhythm and sound of the spoken digits themselves as a memorization device. The mathematician John Horton Conway composed the following arrangement for the first 100 digits,
_ _ _
3 point 1415 9265 35
^ ^
_ _ _ _ _ _ __
8979 3238 4626 4338 3279
** **^^ ^^ ****
. _ _ __ _ _ _. _.
502 884 197 169 399 375 105 820 974 944
^ ^ ^ ^
59230 78164
_ _ _ _
0628 6208 998 6280
^^ ^^ ^^
.. _ .._
34825 34211 70679,
^ ^
where the accents indicate various kinds of repetition.
Another mnemonic system used commonly in the memorization of pi is the Mnemonic major system, where single numbers are translated into basic sounds. A combination of these sounds creates a word, which can then be translated back into numbers. When combined with the Method of loci, this becomes a very powerful memorization tool.

Examples in other languages

Persian

Counting the letters in each word gives 10 decimal places of : خرد = 3, و = 1, دانش = 4, و = 1, آگاهی = 5,...

Hungarian

An interesting alternative:
Another alternative:

Albanian

German

This statement yields π to twenty-two decimal places:
English translation that doesn't encode pi:
Looser English translation that encodes pi:

French

The following poem composed of Alexandrins consists of words each with a number of letters that yields π to 126 decimal places:
An alternative beginning:

Katharevousa (archaizing) Greek

Yielding π to 22 decimal places:

Spanish

The following piem, giving π to 31 decimal places, is well known in Argentina:
Another. This piem gives π to 10 decimal places.

Irish

Romanian

One of the Romanian versions of Pi poems is:
There is another phrase known in Romanian that will help to memorize the number by eight decimal places:
Așa e bine a scrie renumitul și utilul număr. — "This is the way to write the renowned and useful number."

Russian

In the Russian language, there is a well-known phrase in the reform of 1917 orthography of old tradition:
A more modern rhyme is:
A short approximation is: "Что я знаю о кругах?"
In addition, there are several nonfolklore verses that simply rhyme the digits of pi "as is"; for examples, see :ru:Пи |the Russian version of this article.

Russian

In the Russian language, there is a well-known phrase in the reform of 1917 orthography of old tradition:
A more modern rhyme is:
A short approximation is: "Что я знаю о кругах?"
In addition, there are several nonfolklore verses that simply rhyme the digits of pi "as is"; for examples, see :ru:Пи |the Russian version of this article.

Polish

The verse of Polish mathematician Witold Rybczyński :
The verse of Polish mathematician Kazimierz Cwojdziński :
:
An occasionally seen verse related to Mundial Argentina and the Polish football team :

Portuguese

Or in Brazilian Portuguese:
A piem written in a more poetic manner:

Japanese

piphilology has countless mnemonics based on punning words with numbers. This is especially easy in Japanese because there are two or three ways to pronounce each digit, and the language has relatively few phonemes to begin with. For example, to 31 decimal places:
This is close to being ungrammatical nonsense, but a loose translation prioritizing word order yields:
Japanese children also use songs built on this principle to memorize the multiplication table.

Chinese

It is possible to construct piphilogical poems in Chinese by using homophones or near-homophones of the numbers zero through nine, as in the following well known example which covers 22 decimal places of π. In this example the character meaning "mountain" is used to represent the number "three", the character meaning "I" is used to represent the number "five", and the characters meaning "temple" and "die" are used to represent the number "four". Some of the mnemonic characters used in this poem, for example "kill" for "three", "jug" for "five", "happiness" for "six" and "eat" for "seven", are not very close phonetically in Mandarin/Putonghua.
This can be translated as:

Turkish

Czech

Serbian

Italian

Sanskrit

The Katapayadi System of verses is basically a system of code so that things can be defined in a way so that people can remember. The code is as follows:
123456789
कखगघ ङ चछ जझ
टठडढणतथदध
पफबभ म
यरलवशषसह क्ष

With the above key in place, Sri Bharathi Krishna Tirtha in his Vedic Mathematics gives the following verse:
गोपी भाग्य मधुव्रात श्रुङ्गिशो दधिसन्धिग |
खलजीवित खाताव गलहालारसंधार |
If we replace the code from the above table in the above verse, here is what we get.
31 41 5926 535 89793
23846 264 33832792
That gives us π/10=0.31415926535897932384626433832792

Slovene

The following piem gives π to 30 decimal places.

Memorization record holders

Even before computers calculated, memorizing a record number of digits became an obsession for some people. The record for memorizing digits of, certified by Guinness World Records, is 70,000 digits, recited in India by Rajveer Meena in 9 hours and 27 minutes on 21 March 2015. On October 3, 2006, Akira Haraguchi, a retired Japanese engineer, claimed to have recited 100,000 decimal places, but the claim was not verified by Guinness World Records.
David Fiore was an early record holder for pi memorization. Fiore's record stood as an American record for more than 27 years, which remains the longest time period for an American recordholder. He was the first person to break the 10,000 digit mark.
Suresh Kumar Sharma holds Limca Book of Records for the most decimal places of pi recited by memory. He rattled off 70,030 numbers in 17 hours 14 minutes on October 21, 2015.