Explains History and Simple Properties of Density

Ever since Archimedes, a Greek mathematician, inventor and physicist who lived from 287 - 212 B.C., exploded out of his bathtub and ran down the street naked yelling "Eureka," which means "I found it," the principles of water displacement and buoyancy have been understood. In order to determine that King Heiro's crown was indeed made of gold and not silver covered with gold, Archimedes needed two measurements, volume and density.
When a solid object is immersed in water, it moves the same amount of water that it occupies as a solid object. …