Asked in Physics
Who invented the law of displacement?
May 31, 2012 6:37AM
The mathematician Archimedes of Syracuse.
The most common story (which was first told by Vitruvius but doesn't pop up in Archimedes' known works) goes that King Hiero II had a votive crown forged for a temple, and he supplied the pure gold the goldsmith was to use. However, when he got the crown, the King asked Archimedes to determine whether the goldsmith had used all of the gold supplied or substituted silver for some of the gold. Archimedes couldn't melt the crown down into a regular shape to find its density, because he had to leave the crown intact, so he puzzled over the problem for some time. While taking a bath one day, he noticed that the water level rose as he stepped in, and realized that he could use this effect to solve the problem, and supposedly ran through the streets screeching "εὕρηκα!" (heureka!, Greek for "I've found it!") naked. When he performed the test with the crown, he found that the goldsmith had indeed substituted silver for some of the gold.