Ludolph van Cuelen (1540 – 1610) spent most of his adult life calculating π to 35 decimal places.

He was buried at Leiden in the Netherlands. In Germany, π was for a long time referred to as, “The Ludolphine Number”.

There is a memorial to him in the church there. (See left).

In the latter part of the 17th century, Newton and Leibniz independently developed Calculus and new, highly efficient algorithms to calculate approximations for π as sums of infinite series became possible.

In August 2021, researchers at the Swiss University Fachhochschule Graubünden broke the world record for the most calculated digits of π, moving beyond the previous record of 50 trillion digits to reach 62.8 trillion digits using a supercomputer. They also completed their record run nearly four times faster than the previous one.

Marc Rayman is the director and chief engineer for NASA's Dawn mission.

When asked how many digits of π NASA used in its calculations, he replied that for interplanetary navigation, NASA uses 3.141592653589793, (16 digits).

He went out to point out that if you wanted to calculate the circumference of a circle with the same radius as the universe (46 billion light years) to an accuracy equal to the diameter of a hydrogen atom you would need at most only 40 decimal places of π.