The concept of pi (π), the ratio of a circle's circumference to its diameter, was not invented by a single person but has a long history of development.
- The earliest known approximations of pi date back nearly 4000 years, with ancient Babylonians and Egyptians calculating rough values for the ratio
- The first rigorous calculation of pi is credited to the ancient Greek mathematician Archimedes of Syracuse (287–212 BC). He approximated pi by inscribing and circumscribing polygons around a circle and calculating their perimeters, determining that pi lies between 3 1/7 (about 3.14285) and 3 10/71 (about 3.14084)
- Later mathematicians, such as the Chinese mathematician Zu Chongzhi (429–501 AD), further refined pi's value using similar polygonal methods, achieving very accurate approximations like 355/113
- The symbol π to represent this ratio was first introduced by the Welsh mathematician William Jones in 1706 and was popularized by the Swiss mathematician Leonhard Euler in the 18th century
In summary, while Archimedes is credited with the first calculation of pi, the symbol π itself was invented by William Jones and popularized by Euler
. Thus, pi as a concept evolved over millennia through many mathematicians' contributions rather than being "invented" by a single individual.
