Your Blogmeister’s Desk
Happy Pi Day.
As of the current time, Pi is known to more than 22 trillion decimal places. However, only 39 decimal places are needed to calculate the circumference of a circle of a size of the known universe to the accuracy of the width of a hydrogen atom. The 355/113 approximation is so close to accurate that the circumference of a circle with a diameter of 113 miles is 1.9 inches short of 355 miles.
The only reason to ponder more are to show off one’s ability to memorize these kinds of things (I stopped at 50, and can now only do 42), or to show off the power of newer approximation methods (in the pen and paper era) and then the power of each new generation of hardware (in the computer era). As you can probably guess, the computer era set off an exponential growth.