Why having more pi makes life more fascinating.

March 14th is designated as Pi Day, the International Day of Mathematics, because the date is known in American shorthand as 3/14, which is the first three digits of π. Beyond the decimal place, the actual number of digits stretches off into the distance. The date can be specified by truncating pi’s decimal expansion after the second decimal place (3.14).

However, pi gets more and more useful as you add more digits. We can get the Earth’s circumference from its radius using just 11 digits of π, and the error is only 0.5 millimeters. We can calculate the radius of a circle encircling the entire known universe using 38 digits and an idea.