|Archimedes (är'kə-mē'dēz) Pronunciation Key
Greek mathematician, engineer, and inventor. He made numerous mathematical discoveries, including the ratio of the radius of a circle to its circumference as well as formulas for the areas and volumes of various geometric figures. Archimedes created the science of mechanics, devising the first general theory of levers and finding methods for determining the center of gravity of a variety of bodies. He also invented an early type of pump called the Archimedian screw.
An ancient Greek scientist, mathematician, and inventor. He is best known for his investigations of buoyancy.
Note: Archimedes is said to have shouted “Eureka!” (“I have found it!”) as he stepped into his bath and realized that the volume of an object can be measured by determining how much water it displaces. He used this insight to measure the volume of a crown supposedly made of pure gold. After measuring the crown's volume and weighing it, he could calculate its density. He then could prove that the crown was not dense enough to be pure gold.
Note: According to the “principle of Archimedes,” when an object placed in water is weighed, and its weight in the water is compared to its weight out of the water, it seems to lose a definite amount — an amount equal to the weight of the water it displaces. This principle holds not only for water, but also for gases, such as air. A boat floats, or a balloon rises, because it weighs less than the material it displaces. (See buoyancy.) Archimedes is also supposed to have said, with regard to levers and fulcrums, “Give me the place to stand, and a lever long enough, and I will move the Earth!”