Pythagoras' theorem

Mathematics can maintain a sense of wonder. Logic with surprising paradoxes, geometry with optical illusions, calculation with automatic magic tricks are some of the areas where this sense of wonder is encountered, generated by the underlying presence of a mathematical principle. Admiration can also arise from the unexpected, even incredibly beautiful way a problem is solved, thanks to a deus ex machina, this sort of divine intervention that triggers the ha ha, "the flash of understanding" as Martin Gardner called it.

Since the end of the Middle Ages, it has become customary to reduce a quantity to one hundred to compare different data. The rise of the banking system and loans with interest further reinforced the use of percentages to define rates and calculate increases and decreases. Very present in economics, percentages are now used in many other fields, invading the language of journalists and political discourse. Their very delicate handling leads to multiple errors, sometimes bringing confusion where one wanted to be clear and precise.

Pythagoras is much more than a mathematician, whose theorem, famous since Antiquity, has traversed generations and has sparked, over the centuries, an impressive number of proofs. Whether one speaks with deference of the Pythagorean school or with distrust of the sect of Pythagoreans, one cannot forget that this mysterious figure, about whom almost nothing is known, is at the center of a philosophical framework perpetuated by his disciples that influenced, beyond mathematics and astronomy, music itself.