I am very interested in the history of $\pi$. I am first trying to find out who calculated it. Many sources have different answers, from the ancient Egyptians, to Archimedes, to the Babylonians. I still can't find an answer to who first discovered $\pi$, or found a way to calculate it to any degree of accuracy. So who, or which group of people, were the first one(s) to discover/calculate $\pi$?
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2$\begingroup$ It's pretty trivial to notice that pi is about 3 based on stuff like wrapping a rope around a tree. I doubt that that you are going to find a first person who estimated it. $\endgroup$– user466Jan 24, 2015 at 19:30
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1$\begingroup$ To what degree of accuracy? If you want $\frac{22}{7}$, you'll have a very different answer than if you were to want $3.14159$. $\endgroup$– HDE 226868 ♦Jan 24, 2015 at 19:42
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$\begingroup$ To any degree of accuracy $\endgroup$– Anthony PhamJan 24, 2015 at 21:07
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7$\begingroup$ Nobody. Decimal expansion of $\pi$ has infinitely many digits and no pattern is known for them. Are you asking who first came up with a limit formula that can calculate it with any accuracy in principle? $\endgroup$– ConifoldJan 24, 2015 at 21:54
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$\begingroup$ @conifold: even better, it is known that there is no pattern $\endgroup$– Peter M. - stands for MonicaMar 7, 2018 at 3:33
4 Answers
It depends on the meaning of "calculate", since $\pi$ is a transcendental number it can not be "calculated" in the usual meaning of the word.
The first analytic formula (in the form of an infinite series) that in principle can calculate $\pi$ to any required accuracy is probably due to medieval Indian mathematician Madhava, who was first to conceive of infinite series explicitly, or one of his successors. In Europe this series was rediscovered by Leibniz, and is usually called Leibniz series in Western literature.
A semi-geometric "calculation" procedure capable in principle of producing arbitrary accuracy is much older. It consists of approximating a circle by inscribed and circumscribed polygons, and can be traced to ancient Greek orator Antiphon the Sophist. This method was mathematically justified by Eudoxus of Cnidus using what is now called method of exhaustion, and his justification is presented in Book XII of Euclid's Elements. Archimedes perfected the method in On the Measurement of the Circle. He proved rigorously that the ratio of the circle to the square on its radius was the same as the ratio of the circumference to the diameter, so it could be computed both ways.
Approximating the circumference with polygon perimeters is much simpler than approximating the circle area with polygon areas as Antiphon suggested. Using $96$-gons, Archimedes obtained what is now presented as the double estimate $3\frac{10}{71}<\pi<3\frac17$, although to Archimedes $\pi$ was not a number, and the result was phrased geometrically in terms of ratios of magnitudes. In 17th century Huygens refined the method further, and obtained the most accurate estimates to date, but after that analytic methods became more effective.
However, ancient Greeks also had a different concept of calculation, a purely geometric one, that was dominant in their time. A geometric magnitude was considered "calculated" if one could give a geometric construction for it. In the case of $\pi$ this meant constructing a square with area equal to the area of a given circle (or, after Archimedes, a segment with the length equal to half the circle's circumference). With straightedge and compass this is impossible (but it was only shown by Lindeman in 19th century), but Greeks also entertained more broad notions of "construction".
In this broader sense, the circle was first squared by Dinostratus around 350 BC using a curve, now known as the quadratrix. The curve itself was invented a century earlier by Hippias, who generated it by combining uniform linear and circular motions, and used it for angle trisection. In modern terms, from a segment of length $1$ it produces ("calculates") a segment of length $2/\pi$, and from that it is a simple matter to get a segment of length $\pi$ with straightedge and compass. Later Archimedes "calculated" $\pi$ in the same spirit using another curve generated by uniform linear and circular motions, the Archimedean spiral.
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$\begingroup$ Great point about the ultimate incalculability of transcendental numbers! $\endgroup$– DukeZhouJul 12, 2017 at 21:45
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1$\begingroup$ I would interpret it as the first algorithm what could - at least, theoretically - calculate $\pi$ with any precision. $\endgroup$– peterhSep 10, 2019 at 10:44
What do you mean "correctly or not"?
Here is a brief history. The Bible has a sentence which can be interpreted as implying that $\pi=3$.
The EXISTENCE of $\pi$ (the ratio of circumference to diameter) was rigorously proved by Archimedes. He also calculated it approximately. For many centuries it was called the "Archimedes number".
As centuries passed, they calculated it with larger and larger precision. Today it is known to more than a billion decimal digits and more. In 1990-th there was an interesting article in New Yorker magazine about the brothers Chudnovskii who evaluated the first billion digits. (With a huge computer they specially assembled for this purpose).
$\pi$ is a transcendental number, so you cannot "evaluate" it exactly (there is no finite or periodic decimal (or other) expression). This was proved by Lindemann in 1882.
Remark. Let me also add that there was a crank in 19-th century who "proved" that $\pi=4$. I think this is recorded in the Guinness book of records as the LEAST precise value of $\pi$ ever proposed. He offered his work as a gift to the State of Indiana. Indiana parliament had to decide whether to accept the gift. They could not decide. The decision was postponed. It is still postponed.
This gives some evil (or not informed) people a reason to say that "Indiana parliament LEGISLATED that $\pi=4$". Don't believe these people.
EDIT: My mistake: certainly "existence of $\pi$" was known to Euclid. Conifold: thanks for the correction. To address the same remark of Conifold: Euclid and Archimedes (and possibly Eudoxus) certainly understood perfectly what is a "real number" though they used somewhat different terminology of "proportions". Theory of proportions of Euclid is equivalent to the theory of real numbers.
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2$\begingroup$ For some amusement: en.wikipedia.org/wiki/Indiana_Pi_Bill, agecon.purdue.edu/crd/Localgov/Second%20Level%20pages/…, agecon.purdue.edu/crd/Localgov/Second%20Level%20pages/… $\endgroup$– HDE 226868 ♦Jan 24, 2015 at 21:57
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5$\begingroup$ Archimedes did not prove the "existence" of $\pi$, to him it was not even a number. He phrased his results in terms of ratios of magnitudes as did all other Greek geometers. Even if we modernize Greek ratios into "numbers" the "proof" is already in Euclid's Elements, and is usually attributed to Eudoxus aleph0.clarku.edu/~djoyce/java/elements/bookXII/propXII2.html Cruder estimates in terms of inscribed/circumscribed polygons were also done before Archimedes. $\endgroup$– ConifoldJan 24, 2015 at 22:11
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$\begingroup$ Alexandre Eremenko, @HDE226868 , do you guys know of other attempts besides Indiana Pi Bill? Indiana Pi Bill: Other attempts to establish mathematical truth by legislative fiat? $\endgroup$– BCLCMay 10, 2018 at 3:19
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$\begingroup$ Your presentation of the Indiana Pie bill isn't quite correct. The House actually passed it; the Senate is the one that blocked it, after some educative work in the background by concerned intellectuals and a lot of public backlash/mockery in the press. $\endgroup$ May 15, 2018 at 17:05
Since the question specifically says "to any accuracy," I will assume you mean approximations as well.
In this case, the first recorded approximation of $\pi$ comes from the Babylonians, who not only had an awareness of it as being a specific constant, had approximated it's value to $3\frac{1}{8}$ or $3.125$. This is recorded in a tablet fond near Susa dating from 2000 BC.
Both the Egyptians and Archimedes had a value for it but these date from much later.
From the Rhind Papyrus dating from around 1650 BC we find an Egyptian's scribe method for obtaining the area of a circle which is equivalent to using the value $\pi = 3\frac{1}{6}$ or $3.166$ repeating. This is perhaps nearly as good as the Babylonian approximation, but the Egyptians did not apparently have an awareness of it as being a specific constant, this is merely the effective value of it arising from their method.
From Archimedes there is given an approximation of $\pi$ more accurate than either the Egyptian or Babylonian, but this dates from almost 2000 years after the recorded Babylonian value.
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$\begingroup$ You're a little late to the party... Conifold's answer is good enough $\endgroup$ Jan 29, 2015 at 23:10
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4$\begingroup$ Well, it's your question, but you did specifically ask about Archimedes vs Babylon vs Egypt and Conifold left out the Babylonians even though they had an approximation nearly a Millenia before Archimedes or Antiphon or Eudoxus or any other Greeks. Indeed, the mathematical center of the world was at one point, Babylon. After that, it shifts slowly to Egypt, and after that, Greece and the Mediterranean. The top voted answer neglected two whole periods, I felt. $\endgroup$– iPherianJan 30, 2015 at 9:58
There is a terrific summary here which includes the degree of accuracy with chronology, if that is what you are interested in.
Pre computer calculations of π
Mathematician Date Places Comments
1 Rhind papyrus 2000 BC 1 3.16045 (= 4(8/9)2)
2 Archimedes 250 BC 3 3.1418 (average of the bounds)
3 Vitruvius 20 BC 1 3.125 (= 25/8)
4 Chang Hong 130 1 3.1622 (= √10)
5 Ptolemy 150 3 3.14166
6 Wang Fan 250 1 3.155555 (= 142/45)
7 Liu Hui 263 5 3.14159
8 Zu Chongzhi 480 7 3.141592920 (= 355/113)
9 Aryabhata 499 4 3.1416 (= 62832/20000)
10 Brahmagupta 640 1 3.1622 (= √10)
11 Al-Khwarizmi 800 4 3.1416
12 Fibonacci 1220 3 3.141818
13 Madhava 1400 11 3.14159265359
14 Al-Kashi 1430 14 3.14159265358979
15 Otho 1573 6 3.1415929
16 Viète 1593 9 3.1415926536
17 Romanus 1593 15 3.141592653589793
18 Ludolph Van Ceulen 1596 20 3.14159265358979323846
19 Ludolph Van Ceulen 1596 35 3.1415926535897932384626433832795029
20 Newton 1665 16 3.1415926535897932
21 Sharp 1699 71
22 Seki Kowa 1700 10
23 Kamata 1730 25
24 Machin 1706 100
25 De Lagny 1719 127 Only 112 correct
26 Takebe 1723 41
27 Matsunaga 1739 50
28 von Vega 1794 140 Only 136 correct
29 Rutherford 1824 208 Only 152 correct
30 Strassnitzky 1844 200
31 Clausen 1847 248
32 Lehmann 1853 261
33 Rutherford 1853 440
34 Shanks 1874 707 Only 527 correct
35 Ferguson 1946 620
Computer calculations of π
Mathematician Date Places Type of computer
Ferguson 1947 710 Desk calculator
Ferguson, Wrench 1947 808 Desk calculator
Smith, Wrench 1949 1120 Desk calculator
Reitwiesner et al. 1949 2037 ENIAC
Nicholson, Jeenel 1954 3092 NORAC
Felton 1957 7480 PEGASUS
Genuys Jan 1958 10000 IBM 704
Felton May 1958 10021 PEGASUS
Guilloud 1959 16167 IBM 704
Shanks, Wrench 1961 100265 IBM 7090
Guilloud, Filliatre 1966 250000 IBM 7030
Guilloud, Dichampt 1967 500000 CDC 6600
Guilloud, Bouyer 1973 1001250 CDC 7600
Miyoshi, Kanada 1981 2000036 FACOM M-200
Guilloud 1982 2000050
Tamura 1982 2097144 MELCOM 900II
Tamura, Kanada 1982 4194288 HITACHI M-280H
Tamura, Kanada 1982 8388576 HITACHI M-280H
Kanada, Yoshino,
Tamura 1982 16777206 HITACHI M-280H
Ushiro, Kanada 1983 10013395 HITACHI S-810/20
Gosper 1985 17526200 SYMBOLICS 3670
Bailey Jan 1986 29360111 CRAY-2
Kanada, Tamura 1986 33554414 HITACHI S-810/20
Kanada, Tamura 1986 67108839 HITACHI S-810/20
Kanada, Tamura,
Kubo 1987 134217700 NEC SX-2
Kanada, Tamura 1988 201326551 HITACHI S-820/80
Chudnovskys 1989 480000000
Chudnovskys 1989 525229270
Kanada, Tamura 1989 536870898
Chudnovskys 1989 1011196691
Kanada, Tamura 1989 1073741799
Chudnovskys 1991 2260000000
Chudnovskys 1994 4044000000
Kanada, Tamura 1995 3221225466
Kanada 1995 4294967286
Kanada 1995 6442450938
Kanada, Takahashi 1997 51539600000 HITACHI SR2201
Kanada, Takahashi 1999 206158430000 HITACHI SR