Suppressing the Square Root of Two

(Everyone had Lockdown hair in 1980.)

 The video I wanted to post on Saturday for the Solstice would also have made a good Father's Day post, but I still can't upload it so here instead is more classical revisionism. The tone of Carl Sagan's "Cosmos" is so placid and harmonious throughout that when our host suddenly goes on the attack, you listen, especially when the subject of that attack are two of the most revered minds in history.

 "In the recognition by Pythagoras and Plato that the Cosmos is knowable, that there is a mathematical underpinning to nature, they greatly advanced the cause of science. But in the suppression of disqueting facts, the sense that science should be kept for a small elite, the distaste for experiment, the embrace of mysticism and the easy acceptance of slave societies, their influence has significantly set back the human endeavour."

 The "but" Sagan sounds here rings like a bell. He also suggests Plato tried to burn the works of Democritus and even Homer, which shows how little I know. But then again all of this was two and a half thousand years ago, so how much can we know? Here for example is a drawing of the Pythagorean philosopher Hippasus, made two thousand years after his death by drowning. Who knows if he looked like this?

 Some write that Hippasus was drowned as a punishment, either for propogating the knowledge that the square root of two could not be expressed as a ratio of two whole numbers (the original meaning of "irrational") or else for teaching the existence of the dodecahedron, and Sagan explains in the clip above why both might have been considered heretical. Documentary-maker Errol Morris investigates the circumstances surrounding Hippasus' death further here, as far as it's possible to investigate such a thing, and it seems likely he actually just fell in the sea and was martyred after the event, and that his "forbidden" knowledge wasn't suppressed so much as simply extinguished by its own unpopularity. After all the Platonists could never have kept the dodecahedron a secret for ever.
 Sometimes iron pyrite just gets lucky.

Source.