Some of you know Pythagoras as the guy who correctly came up with the ratio of the sides of a right triangle. Now it's time you know him as a murderous cult leader. Maybe.

The dry, yet powerful Pythagorean Theorem haunts the minds of school children (and presidents), but Pythagoras was not the fusty old scholar that many make him out to be. To be sure, he was a math nerd. He loved numbers, and rationality. He just loved them a little too much. Around 500 BC, he founded a religion that came to be called Pythagoreanism. Pythagoras and his followers were sure that numbers explained everything in life, from nature to music. What's more, they were sure that everything in the universe was expressible as the result of rational numbers.

Rational numbers are numbers that can be expressed as the ratio of two whole numbers - in other words, as a fraction. If it wasn't expressible as x/y, they didn't want to hear about it. And I mean they really didn't want to hear about it.

Along, according to legend, came Hippasus. Hippasus was a Pythagorean, and he was an excellent mathematician. That didn't work out well for him. He noticed something about the pentagram. Namely that, if it's divided up, there is a certain ratio between the carved up pieces. Hippasus took the measure of the length of the red side divided by the green side. It's equal to the length of the green side divided by the blue side. And that's equal to the length of the blue side divided by the purple side. And none of these things are expressible as the ratio of two whole numbers. They form the golden ratio, which, in decimals, is approximately 1.61803.