# 101 Pi Facts

## The easiest way to learn everything about Pi is by breaking down every single detail or facts related to it. We've put together 101 of the best facts on PI and the importance.

The easiest way to learn everything about Pi is by breaking down every single detail or facts related to it. Let’s get to know Pi more by learning about its etymology, the number and its symbol, it’s role and usage to the people, a few fun facts about Pi, how NASA uses Pi, and the most wonderful celebration for all the Math enthusiasts - Pi Day!

## The Etymology of Pi 1. Pi has been known and used by civilizations for almost 4,000 years.

2. Reports show that Ancient Babylonians were the first to discover pi, about 4,000 years ago. Evidence also indicates that the Babylonians calculated it as 3.125.

3. Pi has been an integral part of many civilizations and mythologies such as in Ancient Egypt. Early Egyptians believed that the pyramids of Giza were built on the tenets of pi. They once believed that the vertical height and perimeter base of the pyramid has a direct relationship with each other as is the relationship of the circle's radius and its circumference.

4. The pyramids are enigmatic structures, which was proclaimed as one of the seven wonders of the world, was built through pi calculations. At present, the necropolis attracts tourists from all walks of life including scientists due to its archeological significance.

5. The Christians’ King James Bible also cited an approximate value of pi which is the length of the forearm from the elbow to the tip of the middle finger.

6. The symbol for Pi was first introduced in the year 1706 by William Jones, an Anglo-Welsh Philologist. Leonhard Euler, an 18th-century Swiss mathematician, popularized the use of the symbol pi.

7. For over 250 years, the symbol for Pi has been used as an integral part of Mathematics especially in Geometry.

8. In ancient times, mathematicians were obsessed with the number pi and use various and unique methods in calculating it. In ancient China, a mathematician utilized about 200 and then over 3,000 sides of a polygon to reach the value at 3.14159.

9. One of the earliest known records of pi was inscribed by Ahmes in 1650 BC on Rhind Papyrus, a famous scroll from the Egyptian Middle Kingdom bearing mathematical tables and problems. Unfortunately, Ahmes was off by less than one percent of the modern estimation of pi.

10. The Rhind Papyrus was the first attempt to compute pi by building a square inside the circle then measure the diameter of that circle.

11. The “squaring the circle” technique of understanding pi has perplexed mathematicians because the circle in ancient customary practices represents the infinite, eternal, immeasurable, and spiritual realm while the square points to the comprehensive and measurable world.

12. Around A.D. 800, Al-Khwarizmi, who lived in Baghdad, worked on pi calculated to four digits. The term “algorithm” originated from his name, and his text Kitab al-Jabr wal-Muqabala (The Book of Completion Concerning Calculating by Transposition and Reduction) sprung the word “algebra” (from al-Jabr, meaning “restoration” or “completion”).

13. Over the years, the uses and applications of pi have evolved. Prior to the 17th century, pi was only used for circles. In the 17th century, pi was used to compute areas of curves including arches and hypocycloids. In the 20th century, applications of pi expanded to many areas such as probability and mathematical theories.

14. Many mathematicians deemed that it is more appropriate to state that a circle has infinite corners than say it has none. It is plausible to infer that the infinite number corners of the circle correspond to the infinite number of pi.

15. According to history, the Chinese were ahead of the West in searching the digits of pi. Many mathematicians believed that the Chinese language is conducive to mathematical operations especially in the pi game for two reasons: 1) decimal notations, and 2) symbol for the number zero.

## The Number and Symbol 16. Pi is one of the most studied and recognized constants in Mathematics and in the real world as well. Its digits will go on forever and seemingly in a random order which can not be expressed as a ratio or fraction.

17. The record for calculating pi, as of Pi day 2019, is 31.4 trillion digits which broke the previous world record of 22 trillion digits.

19. The Greek symbol ℿ comes from the first letter of the word periphery and perimeter.

20. The ℿ symbol was standardized in the 1700s while the equal sign (=) emerged in 1557.

21. We can never calculate the exact value of pi, thus, we will never know the accurate circumference of a circle.

22. Pi is an irrational number and mathematicians can express it as algorithms and sequences.

23. One can measure a circle in two ways: one is the circumference which is the distance around the perimeter and the other one is the diameter which is the distance across the part of the circle.

24. It won’t matter how big or small the circle, the ratio of the circumference to the diameter is the value of Pi.

25. There is an interesting aspect the name pi came into existence. Before the term “pi” was coined, the scientific community particularly had to say numerous words. The descriptive phrase for pi they could employ was “the quantity which when the diameter is multiplied by it, yields the circumference”. William Jones, a non-so-popular mathematician, was the brainchild behind coining the term pi.

26. The number of digits in pi is a marvel and perplexing in itself. In its essence, humans can never find all the decimal numbers of pi. In 1665, Sir Issac Newton enumerated pi to its 16 decimal places. This remarkable event was even before the computers were developed, thus, being able to identify more than 15 digits was a feat.

27. In the early 1700s, Thomas Lagney, a French mathematician, calculated 127 decimal places of pi making him a record holder of his time.

28. In the 20th century,  the number of pi digits increased unlocking from about 2,000 decimal places to 500,000. In 2017, a Swiss scientist broke the world record to a whole new level by accomplishing more than 22 trillion digits which took him more than a hundred days to calculate.

29. 99,959 zeros, 99,758 1s, 100,026 2s, 100,229 3s, 100,230 4s, 100,359 5s, 99,548 6s, 99,800 7s, 99,985 8s, and 100,106 9s are the first million decimal digits of pi.

30. Pi has a special bond with the circle. Coincidentally, the circle’s angle spans 360 degrees as its circumference in which the number 360 is the 359th digit position of pi.

31. Did you know? the first 144 digits of pi summed up to 666, which many people say is “the mark of the Beast”. Also, 144 = (6+6) x (6+6).

32. The first six digits of pi, which is 31415, pop up in order at least six times in the first 10 million decimal places of pi.

33. The Feynman point, after physicist Richard Feynman, is a sequence of six 9’s which occurs in the 762nd decimal place of pi.

34. Under Diophantine approximation, 22/7 is widely used as a fraction or rational number for pi.

35. Since pi is closely associated with the circle, it is found in many formulas, particularly in the disciplines of geometry and trigonometry, concerning circles, spheres, or ellipses.

36. The circumference and area of a circle and the volume and area of a sphere use pi to calculate them.

37. Piphilology is the practice of recalling the digits of pi which utilizes mnemonic techniques.

## Pi to the People 38. One of the most important and influential figures of the Renaissance era, artist and scientist Leonardo da Vinci briefly worked on “squaring the circle,” or calculating pi.

39. Many brilliant minds and geniuses have a relation with the Pi day. World-famous physicist Albert Einstein was born on Pi Day, March 14, 1879. On the other hand, renowned English theoretical physicist Stephen Hawkings died on 3/14, Pi day at the age of 76.

40. John Donne denounces any efforts to find the exact value of pi or to "square a circle" as this correlates an attempt to rationalize God.  This personal view is manifested in his poem "Upon the Translations of the Psalms by Sir Philip Sidney, and the Countess of Pembroke, His Sister."

41. On 21 March 2015, Rajveer Meena of VIT University, Vellore, India achieved a world record title for reciting the most number decimal places of Pi. For an astonishing 10 hours, Rajveer was able to recite 70,000 decimal places. He wore a blindfold throughout the duration of the recall to maintain the credibility of the record.

42. Mike Keith wrote an entire book, entitled ‘Not a Wake’ which was created in an entire language made on the number Pi. Some people love pi that they invented a dialect in which the number of letters in the successive words spells the same digits of pi.

43. Some pi enthusiasts labeled pi as a transcendental number. In 1760, Swiss mathematician Johann Heinrich Lambert proved that pi is irrational by showing the tangent of x in continued fraction.

44. Meanwhile, Carl Louis Ferdinand von Lindemann, a German mathematician, upheld that pi is a transcendental number, which means that it is not a root of any polynomial.

45. In Carl Sagan’s book Contact, scientists dig deep into the mystery of the number pi to unearth and unlock the cryptic messages from the creator of mankind.

46. Ludolph van Ceulen published his 20-decimal value of pi in 1596 which he later expanded to 36 decimals. The Dutch-German mathematician spent a major part of his life calculating the numerical value of pi that after his death, the first 36 digits of pi was engraved on his tombstone in Leiden.

47. British Mathematician William Shanks also worked on discovering the numbers of pi by hand. He exhausted many years and found the first 707 digits which he calculated manually. Unfortunately, the 527th digit he found was wrong which rendered his efforts of finding the remaining digits pointless as they are incorrect by default.

48. In 1888, an Indiana country doctor declared that he learned the precise measure of a circle with the aid of the supernatural. Cognizant of his supernatural knowledge, he filed a proposal and sought the assistance of Indiana’s legislature to pass a bill that he could copyright his genius findings of rounding of pi to 3.2. However, a math professor in the legislature objected that the proposed bill would result in a flawed value of pi.

49. An example of a mnemonic for pi was generated by James Jeans, an English Scientist, which translates to "How I want a drink, alcoholic of course, after the heavy lectures involving quantum mechanics."

50. Michael John Blake, an Austin-based musician, produced the musical representation of pi to 31 decimal places at 157 beats per minute, which is 314 halved.

51. Michael Caine, Chris Klein, Taylor Hanson, and Billy Crystal are some celebrities who were born on Pi day (March 14).

52. In present-time internet culture, computer scientist Donald Knuth is one of many individuals who pay homage to pi in which he devises the version numbers of his program TeX by 3, 3.1, 3.14, and so on. 53. Many people find pi as just another weird or boring number in the realm of Mathematics.

54. Due to its significance in structural planning, Pi as the core principle has a special place in the hearts of architects.

55. The first three digits of pi which is 3.14 look like PIE backward.

56. In the TV show Star Trek episode “Wolf in the Fold,”  protagonist Mr. Spock fooled a devious computer into commanding it to compute pi’s last digit and destroys it.

57. There have been debates on the usefulness of pi albeit loved by many especially math lovers. Some recognized that tau (2π) is an intuitive irrational number as it can be multiplied with radius and find the circumference of the circle more intuitively. Mathematicians are more inclined to intuitiveness which tau has more appealing than pi.

58. Each year, a circular parade is held at the Exploratorium science museum and participating individuals hold one of the digits in the number pi.

59. The film Pi: Finding Faith in Chaos is a 1998 American neo-noir thriller film which portrays the protagonist’s search for answers about pi and, in turn, the truth about the universe itself. The search made him crazy in the process. However, the good news was that the movie won the Director’s Award at the Sundance Film festival.

60. In 2008, a crop circle was found in Wiltshire, England which exhibited a coded image comprising the first ten digits of pi.

61. Computing pi is a stress test for computers since it will process a huge volume of decimal numbers. Picture this out in your mind: if you were to print a billion decimal values of pi in normal font and size, it would span from New York to Kansas. The stress test works just like a cardiogram indicating the level of the processor's activity.

62. The pi phenomenon has also reached the fragrance industry where Givenchy made a cologne for men and named as such. The product marketing emphasizes that the cologne is capable of boosting the sexual appeal of intellectual and visionary men.

63. The number Pi was used in the famous O.J. Simpson murder trial where the defense attorney and FBI agent’s argument centered around the value of pi. However, the argument over pi showed that the federal agent’s findings in the case were inconclusive due to the inexact usage of pi.

64. There are instances where comedians use pi as punchlines or crack a joke. Comedian John Evans, once made a joke in his performances saying, “What do you get if you divide the circumference of a jack-o’-lantern by its diameter? Pumpkin π.”

65. Umberto Eco’s famed book Foucault’s Pendulum associated pi with the mysterious pendulum in the novel.

66. The numerical value of pi is infinitely long. However, the number 123456 does not appear in the first million decimal values of pi. Thus, it is interesting enough that if a million digits of pi do not have the sequence 123456, then such constant is the most unique number.

67. Due to pi’s mysterious infinite value, human beings are obsessed with it that some are looking for analogies and patterns in this number to almost everything from the tangible to the intangible.

68. Math lovers will find how amazing the number pi is when used in calculating many mathematical operations. As an example, rounding the number pi to nine decimal digits in computing the earth’s circumference would result in an amazing precise figure. Amazingly, the number pi will only err to 1/4th of an inch for every 25,000 miles.

69. Some people are going crazy about finding the most number of digits of pi and some considered it like a competition that never ends. In 2010, an Ameican computer wizard and a Japanese engineer broke the world record for the most number of pi digits by computing up to five trillion digits. Astonishingly, they did not use any supercomputers rather with desktop computers, 20 external hard disks, and their wits.

70. For cosmological computations, mathematician JÖrg Arndt recommends that 39 digits of pi are ample enough to compute the size of the universe to the nearest atom.

71. In real-world applications, some industries such as manufacturing plants use pi in calculations that would reduce waste production by ensuring that resources are optimized. Other practical uses pi in real-world applications are: 1) tracking population dynamics by statisticians, 2) studying the eye’s structure as well as the function of the DNA, 3) engineers can calculate the areas of the aircraft’s exterior, and 4) navigation purposes such as geographical positioning system or GPS.

72. There is a website with a domain name “The Pi-Search Page” which searches a person’s birthday and other notable numbers in the digits of pi.

73. In 2014, the largest human pi symbol was formed with 589 people at a grammar school in Germany.

74. In 2017, the longest human representation of pi digits was carried out by 520 teachers and students in Todi, Italy.

## NASA and Pi

75. With the help of pi, engineers can determine the size of the parachute required to generate the drag needed to slow down a rover or lander during Martian missions.

76. During Saturn missions, engineers used a method called pi transfer to change the spacecraft’s orbit.

77. In mapping unexplored worlds, scientists use pi in the formula for surface area to determine the number of images it will take to map a planet or celestial body.

78. Due to uncertainty in landing rover or lander on Mars, engineers use pi as a tool to estimate the amount of uncertainty relative to the position.

79. Space scientists use pi to search for other planets that orbit another star other than the Sun.

80. NASA uses pi to locate the inner and outer fringes of the habitable zone and with the use of Kepler's third law, scientists can calculate other useful information such as how long does an exoplanet revolves around its star and identify if it's in the habitable zone.

81. Astronomers also use pi to study Martian earthquakes which will soon be termed as marsquakes.

82. Engineers use pi to communicate with the spacecraft in deep space network to send messages and process those that are sent back.

83. For Mars rovers to operate and function such as taking pictures, moving robotic arms and turning wheels, there is a need to measure the degrees and radians, thus, pi is regularly used for calculating these operations.

84. Pi is valuable for engineers to put spacecraft into orbit around other planets by determining the gravitational pull, compute the brakes, among other tasks.

85. To track the movements of asteroids, scientists can find the object's angular velocity which is measured in radians per second, which is slices of a circle or pi.

86. To keep the rover wheels turning, pi is used to identify how far the rover should travel which is done by calculating the distance from one wheel mark to another.

87. Scientists use pi to investigate extraterrestrial ice by computing beamwidth of the laser and determine how much energy is hitting the targeted area.

88. Pi is critical in calculating how much fuel is available in spacecraft tanks and how fast the fuel travels through the fuel lines.

89. Pi is also crucial in calculating the size of features on the surface of cosmic entities such as Earth.

90. Planetary geologists take advantage of pi in computing craters which in turn reveal clues on how it was formed and the surface it impacted.

91. Without visiting, planetary scientists can study the physical make up of planets and asteroids through the help of pi by determining the volume, densities, and mass of planetary materials.

92. Despite the thick, swirling strong winds in the atmosphere of gas giants like Saturn and Jupiter, scientists are also able to study the composition of the planet's atmosphere with the use of pi and a spacecraft sensor data.

## Happy Pi Day! 93. Physicist Larry Shaw, known as the Prince of Pi, started Pi day on March 14 at  San Francisco’s Exploratorium.

94. In many parts of the world, people, especially nerds and geeks, celebrate March 14 or 3/14 as pi day that corresponds to the first digits, 3.14. However, the celebration takes place at 1:59 pm following the symbol’s exact number 3.14159.

95. Accordingly, the purpose of celebrating pi day was to increase people's enthusiasm for math and science

96. In 2009, the US through the House of Representatives passed a resolution recognizing Pi Day.

97. Some countries, including the UK, use the format for Pi day by writing the day first then followed by the month which would make it look like 14.3. Some countries like America find it confusing.

98. Some universities celebrate Pi day by sending application decision letters to potential students to arrive on Pi day itself.

99. On Pi day 2019, this was the first time the power of the cloud was used to calculate with such magnitude that it achieved 31.4 trillion digits.

100. At Princeton University, they organize an Albert Einstein lookalike event on Pi day.

101. On March 14, 2018, 1,182 participants secured their place in the Guinness book of world records for creating a human Pi chain. They are from The Sultan’s School in Seeb, Oman.

Whew! That was a lot! If you think we missed other important Pi facts on this list, do let us know! There's nothing more we want than satisfying your crave for knowledge on everything Pi.