Throughout the 19th century, the true value of pi was reported by several different authors. Unfortunately, they all gave differing values of pi.
In 1977, mathematician Underwood Dudley compiled the 50 results presented above and came to an interesting comclusion:
He concluded that π is decreasing. The best fit is πt = 4.59183 – 0.000773t, where t is the year A.D. — it turns out we passed 3.1415926535 back in 1876 and have been heading downward ever since.
And that means trouble: “When πt is 1, the circumference of a circle will coincide with its diameter,” Dudley writes, “and thus all circles will collapse, as will all spheres (since they have circular cross-sections), in particular the earth and the sun. It will be, in fact, the end of the world, and … it will occur in 4646 A.D., on August 9, at 4 minutes and 27 seconds before 9 p.m.”
There is some good news, though: “Circumferences of circles will be particularly easy to calculate in 2059, when πt = 3.”