People love to describe and visualize pi. A lot.

What’s with our odd obsession with calculating or memorizing this irrational number out to seemingly absurd levels of precision? Whether it’s reciting the first 100,000 digits from memory (the current record), or calculating it out to 10 *trillion* digits, some people can’t help but dig deep into irrationality.

Frankly, much of that is to just prove that it can be done. While calculating pi out to ludicrous limits can be a good test for high-powered computing and to test mathematical theories, it’s no more necessary for science than you being able to shove 37 marshmallows in your mouth is to your life (or maybe 38 … push yourself).

But sometimes, just doing something to prove we can is worthwhile on its own. This is why people run marathons and eat 69 hot dogs in ten minutes.

So how much pi is enough pi? NASA can satisfy pretty much all of their spaceflight needs by reaching out to just 15 or 16 places, and the National Institute for Standards and Technology meets its most demanding computer benchmarks with just 32 digits.

And how many do we need? You could figure out your position on a circle with the radius of the Earth down to the *millimeter *with just 10 digits of pi. As for me, I won’t be memorizing anything more than where the “pi” key is on my calculator. As Albert Einstein once said, “*[I do not] carry such information in my mind since it is readily available in books.*”

It’s poetic, really. Pi is a sort of Platonic ideal. It’s a value that, no matter how far we dig back into its depths, we will never fully describe, its irrational tail stretching further and further back into infinity. The circle never ends.