Happy π Day! Pi has been known to most cultures since antiquity, with the earliest known calculations dating back to the Great Pyramid at Giza, whose perimeter measures about 1760 cubits and a height of about 280 cubits, giving the ratio 1760/280 ≈ 6.2857 which is approximately equal to 2π ≈ 6.2832. The earliest verifiable use of the lower case Ancient Greek letter π (pi) to symbolize the ratio of the diameter of a circle to its circumference was by the mathematician William Jones in his 1706 work a New Introduction to the Mathematics. In that work, however, Jones says that the ‘truly ingenious Mr. John Machin’ used it before him. There are many ways to derive π (pi), from the rough approximation of 22/7 to the most recent calculations that extend π (pi) to over a trillion digits, calculated over months and years with supercomputers.
Apologies to all those not in the Eastern Time zone of the United States-this post should hit your dashboard on 3/14 at 1:59.
Enjoy π (pi) day, and have a slice of pie!