Archimedes: Streaking Around

Archimedes was a Greek mathematician who lived in the third century BCE. Hero, the king of Syracuse, gave Archimedes the task of determining whether Hero’s new gold crown was composed of pure gold, which it was supposed to be, or whether the jeweler had substituted an alloy and pocketed the extra gold. Archimedes figured that if he could measure the density of the crown and compare it to that of pure gold, he’d know whether the jeweler had been dishonest. But although he knew how to measure the weight of the crown, he couldn’t figure out how to measure its volume in order to get the density.

Needing some relaxation, he decided to bathe at the public baths. As he stepped into the full tub and saw the water overflow, he realized that the volume of his body that was submerged was equal to the volume of water that overflowed.

He had his answer for measuring the volume of the crown. Legend has it that he got so excited that he ran home naked through the streets, yelling, “Eureka, eureka!” (I’ve found it!).