section_path: Culture/Science and technology
section_name: Science and technology
paragraph_text: Science and technology
  
  Ancient Greek mathematics contributed many important developments to the field of mathematics, including the basic rules of geometry, the idea of formal mathematical proof, and discoveries in number theory, mathematical analysis, applied mathematics, and approached close to establishing integral calculus. The discoveries of several Greek mathematicians, including Pythagoras, Euclid, and Archimedes, are still used in mathematical teaching today.
  
  The Greeks developed astronomy, which they treated as a branch of mathematics, to a highly sophisticated level. The first geometrical, three-dimensional models to explain the apparent motion of the planets were developed in the 4th century BC by Eudoxus of Cnidus and Callippus of Cyzicus. Their younger contemporary Heraclides Ponticus proposed that the Earth rotates around its axis. In the 3rd century BC, Aristarchus of Samos was the first to suggest a heliocentric system. Archimedes in his treatise The Sand Reckoner revives Aristarchus' hypothesis that "the fixed stars and the Sun remain unmoved, while the Earth revolves about the Sun on the circumference of a circle". Otherwise, only fragmentary descriptions of Aristarchus' idea survive. Eratosthenes, using the angles of shadows created at widely separated regions, estimated the circumference of the Earth with great accuracy. In the 2nd century BC Hipparchus of Nicea made a number of contributions, including the first measurement of precession and the compilation of the first star catalog in which he proposed the modern system of apparent magnitudes.
  
  The Antikythera mechanism, a device for calculating the movements of planets, dates from about 80 BC and was the first ancestor of the astronomical computer. It was discovered in an ancient shipwreck off the Greek island of Antikythera, between Kythera and Crete. The device became famous for its use of a differential gear, previously believed to have been invented in the 16th century, and the miniaturization and complexity of its parts, comparable to a clock made in the 18th century. The original mechanism is displayed in the Bronze collection of the National Archaeological Museum of Athens, accompanied by a replica.
  
  The ancient Greeks also made important discoveries in the medical field. Hippocrates was a physician of the Classical period, and is considered one of the most outstanding figures in the history of medicine. He is referred to as the " father of medicine " in recognition of his lasting contributions to the field as the founder of the Hippocratic school of medicine. This intellectual school revolutionized medicine in ancient Greece, establishing it as a discipline distinct from other fields that it had traditionally been associated with (notably theurgy and philosophy), thus making medicine a profession.