After thousands of years of trying, mathematicians are still working out the number known as pi or “π”. We typically think of pi as approximately 3.14 but the most successful attempt to calculate it more precisely worked out its value to over 13 trillion digits after the decimal point. We have known since the 18th century that we will never be able to calculate all the digits of pi because it is an irrational number, one that continues forever without any repeating pattern. But there is a semblance of order to all that "random" chaos.