Memorize 39 Digits of Pi
You Only Need 39 Digits of Pi
Posted Saturday, March 28, 2015
Why 39 digits? You only need 39 digits of pi to measure the circumference of the observable universe within the width of one hydrogen atom. Memorize 3.14159265358979323846264338327950288419 at http://memorize39digitsofpi.com and buy the t-shirt to show off to your friends!