“If the radius of a circle is 14cm, find its circumference. Take 3.14 as π.” You have probably encountered such math exercises. At the time, unless you cared about the subject, chances are you did them for the marks and never cared about the origin of the PI symbol or who came up with the constant.
It turns out that Pi is more interesting than it was during the school days. Also known as the circular constant, Ludolph’s number, or Archimedes’ constant, PI refers to how the circumference of a circle relates to its diameter. Today we learn about some interesting Pi facts that will make your day.
1. The Symbol Has Been in Use since Time Immemorial
While it took until the 1700s for people to recognize the symbol π, its adoption and use prevailed. Documents show that ancient Egyptians used the idea to build the great pyramids as early as 1650 BCE. Today, the pyramids are among the 7 wonders of the world.
William Jones, a great mathematician from Wales, popularized the pi symbol. Before then, people used to refer to pi digits as “the quantity used to find the circumference of a circle after multiplying it with the diameter.” They eventually got tired of saying this, so William Jones, Isaac Newton’s friend, was their saving grace.
2. The Value of PI is Infinity
Pi’s value is irrational and infinity – you cannot express it as a simple fraction. Over time, people have tried to calculate its value with no success. All they keep finding is more digits. Before the 1900s, most math calculations, including Pi’s, were hand calculated. The records were set at 500s.
The introduction of computers did not result in a breakthrough, either. Instead, it resulted in more Pi numbers amounting to millions. Today, the number is in the trillions after Emma Haruka broke PI enthusiast Peter Tuareb’s record in 2019. She recently extended the Pi digits to 100 trillion.
3. Akira Haraguchi Holds the Record for the Most Memorized PI Digits
Since there is no specific limit for PI numbers, enthusiasts usually engage in part-time memorizing tests. Akira Haraguchi holds the unofficial record after reciting 100 000 PI digits in 2006. The event held in Tokyo took about 16 hours to complete.
However, as mesmerizing as Akira Haraguchi’s record is, the Guinness world records recognize Rajveer Meena as the holder of the highest memorized PI numbers. Rajveer set the record on March 21, 2015, after correctly reciting 70,000 π digits.
To improve its credibility, the contestant wore a blindfold throughout the 10 hours he used to set the record.
4. March 14 Is The National PI Day
Whether a circle is equal to the size of the world or smaller than an atom, the ratio of its circumference to the distance across it (diameter) is always equal to PI (π). So, to celebrate how special it is, we usually celebrate National PI Day every March 14. The first event was held in 1988 and was started by Larry Shaw.
The Exploratorium science museum usually hosts people who form circles, each holding a pi digit to mark the day. Authorities hope by doing this, they will encourage American students to take science and math lessons enthusiastically.
Pi Day is marked in other regions by dad jokes, symbol creation, numbers play, PI number memorization, and fun facts. For instance, did you know that π (piwas) is the 16th letter in the Greek alphabet while the letter P is 16th in English?
Here is an example of a dad joke: “What reptiles are likely to excel in a math contest?” The answer is “Pi-thons.” We shouldn’t have started this PI conversation, because it will continue forever.
5. Its Use Has Occasionally Been Debated
Since pi digits are infinite, we can never tell a circle’s exact area or circumference. With that in mind, the usefulness of the much-loved pi has occasionally been questioned. A few mathematicians believe that tau, an equivalent of 2 π, is a better alternative.
They argue that it’s more intuitive to calculate a circle’s circumference by multiplying tau by its radius. Additionally, if you divide tau by 4, the resulting angle is the circle’s quarter. So far, the debates have not held any water, so the pi continues to reign.
6. William Shanks Found the first 707 PI Digits.
William Shanks was an English Mathematician whose prowess earned him the nickname “computer.” Of course, this was before the massive revolution in the technological industry. He lived between 1812 and 1882. In 1873, he decoded the first 707 pi numbers.
This was a great deal at the time, considering he had no technological aid (calculators or computers). However, it was later discovered that he made a mistake on the 528th digit. Given that he got the first 527 digits correctly, it’s worth commending.
7. There Is a Common PI Magic Trick
Buffon’s Needle is a common math trick used to calculate the value of PI. You will need needles (but matchsticks with the heads cut off or toothpicks can do) and a piece of lined paper.
Start by measuring and recording the spaces between the lines of your piece of paper. Also, measure the size of your stick. Place your lined paper on a flat surface, for example, a table. Drop your stick from a height of about 5cm from the paper. Record the times the stick touches and fails to touch the paper lines.
Repeat the process a hundred times, then record the percentages. To calculate pi, use the formula π=2L divided by XP, where L is the length of your matchstick, X is the spacing between the lines on your paper, and P is the number of times the stick crossed a line.
So, assuming the percentage of the stick crossing the lines is 49, the length of your matchstick is 31, and the space between the lines is 40mm, your calculations should equal 3.16. While this is not the accurate value of pi, it’s close enough.