The Pythagorean theory is probably more widely known than any other complex mathematical idea. The theorem was first used by the Eygptians , butthey had no mathematical proof that the idea was correct. Pythagoras is credited with being the first to prove the theorem.

The Pythagorean theorem, which is important in all technology, proved that the sum of the squares on the short two sides of a right triangle is equal to the square of the hypotenuse. (A right triangle has one angle of 90 degrees.)

Pythagoras was born about 582 B. C. in Samos Greece. Almost nothing is known about his personal life. He traveled through the Mediterranean, visiting the Eygyptian centers of learning. In 529 B. C., he was driven from Greece by the tyrant King, Polycrates. With his followers, Pythagoras founded a kind of a religious brotherhood devoted to mathematics as well as religion and philosophy. The members of the society were all aristocrats, sworn to secrecy. As a result, the brotherhood was looked at with suspicion by the common people. The people killed most of the brotherhood's members in a political uprising. No one knows if Pythagoras escaped or was killed. The entire brotherhood was destroyed in 400 B. C.

Pythagoras and his followers believed that the human soul was immortal and returns to earth after it's body is killed into different people. Today, this is called reincarnation. He believed that animals and men are related and that a human soul might be born again in a animal. This, he said, could be avoided if a man lived a perfect and righteous life. As a result, self-discipline, purity, and temperance were all virtues that the Pythagoreans tried to keep.

The society gave Copurnicus the first inkling that the sun was at the center of the universe. Pythagoras believed that the path of the planets must be circular. The circle, he argued, was the most perfect path. The earth, the stars, the planets, and the universe as a whole were also spherical, he said, because the sphere is the most perfect solid figure.

In addition to astronomers and mathematicians, the brotherhood had biologists and anatomists. They discovered the optic nerve and the Eustachian tubes.

The Pythagoreans brought their knowledge of science into the realms of music. Pythagorus siad that a musical note is a pure sound that is pleasing to the ear. He noticed that when certain pitches were played together, harmony was produced, while when other pitches were played together, the sound was altogether jarring. He discovered that a simultaneous note produced by strings had the lengths in simple ratios one to the other to produce harmony. Musicians know these combinations to be the purest.

Two hundred years later, Aristotle said this of the Pythagoreans, 'They applied themselves to the study of mathematics and were the first to advance in science." Present day scientists are still trying to reduce the universe to the certainties of mathematical formulas, just like Pythagoras.