A Brief History of Pi (π) and Pie (🥧)

The Wiley Network

A Brief History of Pi (π) and Pie (🥧)

Meghan Marino, Associate Manager, Field Marketing, Wiley

February 19, 2024

Happy Pi (π) Day! π isn’t just a random number; it’s the key to understanding circles. By comparing the circumference of a circle to its diameter, we arrive at the magic number of 3.141592653589(…), better known as – yes, you guessed it – pi.

But this mathematical constant isn’t just celebrated through numbers; it’s often paired with its homophone: pie. So, this year, we want to look at a history where mathematics and delicious treats collide – with materials from Wiley Digital Archives!

How old is Pi?
Pi has been around a long time – close to 4,000 years in fact. Ancient Babylonian tablets from circa 1900 BC calculated pi’s value at 3, while one tablet refined that number to an even closer 3.125. Flashing forward to around 1650 BC, the Ancient Egyptians found an approximate value of 3.16 before the first close approximation was done by the ancient Greek mathematician Archimedes (287-212 BC), who declared pi’s value somewhere around 22/7, or 3.142857. The brilliantly precise Chinese mathematician Zu Chongzhi took π even further during the 5th century, refining its value between 3.1415926 and 3.1415927.

Our understanding of this magical number has been a long, collaborative work in progress involving mathematicians from all over the world. By 1750, pi was given its current symbol, expressed by a value with over 100 digits. Even in the 21st century, researchers continue to expand its meaning. The current record sits at a value of 62,831,853,071,796 digits, a number that took Swiss mathematicians over 108 days to obtain.

Archimedes in the Archives
While many archival documents cover Archimedes, perhaps the oldest in our archives is dated from 1599. “Scholarum mathematicarum libri unus et triginta” or “Thirty-one books of mathematical schools” speaks of Archimedes’ first theorem on the dimension of a circle, among his other mathematical accomplishments.

View the collection: Pierre de la Ramee, Lazarus Schoner, RCP Library, M.D.XCIX, The Royal College of Physicians archive. (Available via trial or institutional access)

Zu Chongzhi in the Archives
From the times of ancient China and beyond, a manuscript highlighting accomplished scholars writes that Zu Chongzhi was “the first person who accurately calculated the value of π to seven decimal places.”

View the collection: Qin Shi, Essays, literary works, and biographical papers, 1992, The Royal Antropological Institute of Great Britain and Ireland archive. (Available via trial or institutional access)

A Bite-Size History of Pie
Before refrigerators, pie served as a tasty means to preserve food. So, how long have we enjoyed sweet and savory treats like apple pie and pizza pie? Well, the first written recipe was for a rye-crusted goat cheese and honey pie, and is credited to the Romans by the American Pie Council. But the true age of these treats is debatable; there is evidence of a recipe for chicken pie on a carved Ancient Egyptian tablet dating back to over 2000 BC.

Pie in the Archives
Pizza has become so ingrained in numerous cultures that it’s hard to picture a time when it was considered exotic. But a book on Naples from 1901 shares a perspective completely in awe of the food that many of us love and can’t picture life without.

“’Pizza’ may be seen in every street in Naples,” writes British author Arthur H. Norway. “It is a kind of biscuit, crisp and flavoured with cheese, recognizable at a glance by the little fish, like whitebait, which are embedded in its brown surface, dusted over with green chopped herbs.”

View the collection: Arthur H. Norway, Monographs, 1901, Royal Geographical Society (with IBG) archive. (Available via trial or institutional access)

In a newspaper article titled "America is a Bad Tourist Trap," a disgruntled British visitor expresses their dissatisfaction with American delicacies. The bold statement is made that “’homemade blueberry pie’ in the roadside diner is revealed at every trial as the same old tasteless slice of purple glue,” among many other quirky insights from a disappointed Brit.

View the collection: David Holden, William Buller Fagg Collection, n.d., the Royal Anthropological Institute of Great Britain and Ireland archive. (Available via trial or institutional access)

Curious About Mathematical History?
As we savor the rich history of pi and pie, we invite you and your researchers to see what else you can find on Wiley Digital Archives. Revisit the mathematical marvels that advanced our understanding of science, or journey through the history of delectable treats from all over the world with a free trial.

If you’re curious about other stories from the archives, we invite you to dive into the fascinating life of Sophie Germain, a self-taught mathematician who, under a male pseudonym, submitted college assignments and became the first woman to receive an award in the field of mathematics.