Archimedes, Greek mathematician, physicist, and inventor. Born Syracuse, Sicily, about 287 B.C. Died Syracuse, 212 B.C.
Archimedes was the greatest mathematician and physicist of the ancient world. He discovered many basic principles of geometry. He developed a method that is nearly identical to modern integral calculus for computing the area and volume of geometric figures, and determined a value for π or pi, equal to 3.14. Archimedes also devised an exponential system of arithmetic notation. This exponential notation system enabled him to write very large numbers concisely. In the field of physics, Archimedes was the first to state the laws governing levers. He discovered the principle of buoyancy, known as Archimedes' principle; and he developed the science of hydrostatics, the study of pressure and equilibrium in fluids. As an inventor. Archimedes is credited with the Archimedean screw, long used to raise water for irrigating fields. It is said that during the siege of Syracuse by the Romans he invented weapons of war that delayed the city's fall.
One of the many legends about Archimedes describes his discovery of a way to find the volume of irregular or complicated objects when the volume cannot be calculated mathematically. Archimedes was asked by King Hiero of Syracuse to determine whether the royal crown was made of pure gold, or whether the goldsmith had dishonestly alloyed the gold with silver. Archimedes realized that a crown made of gold and the lighter metal silver would be lighter than a crown made of pure gold. The shape of the crown was so complex, however, that he could not calculate its exact volume, and so he was unable to compare its weight with that of an equal volume of pure gold. But as he lowered himself into his bath one day, he noticed the water overflowing, and realized that any object submerged in water must displace an amount of water equal to its own volume. The discovery of this principle enabled Archimedes to measure the volume of the crown and to prove that it was not pure gold. He is said to have been so overjoyed by his discovery that he dashed naked through the streets, shouting, "Eureka! Eureka!" ("I've found it! I've found it!").
From this discovery, Archimedes developed the principle of buoyancy, which states that a partially or totally submerged body is acted on by an upward force equal to the weight of the displaced liquid. This explains why submerged bodies seem to lose weight, and why divers can lift heavier objects under water than they can on land.
Archimedes was the son of Pheidias, an astronomer. He studied in Alexandria and spent the rest of his life in Syracuse. According to legend, he met his death during the Roman invasion of Syracuse. Archimedes was absorbed in drawing a geometric diagram in the dust. A Roman soldier stepped on the drawing, causing Archimedes to exclaim, "Don't disturb my circles!" The soldier, angered by the order, drew his sword and killed him.