History of Science in Classical Antiquity - Hellenistic Period

Hellenistic Period

Further information: Hellenistic astronomy, Hellenistic mathematics, and Hellenistic geography

The military campaigns of Alexander the Great spread Greek thought to Egypt, Asia Minor, Persia, up to the Indus River. The resulting Hellenistic civilization produced seats of learning in Alexandria in Egypt and Antioch in Syria along with Greek speaking populations across several monarchies. Hellenistic science differed from Greek science in at least two ways: first, it benefited from the cross-fertilization of Greek ideas with those that had developed in the larger Hellenistic world; secondly, to some extent, it was supported by royal patrons in the kingdoms founded by Alexander's successors. Especially important to Hellenistic science was the city of Alexandria in Egypt, which became a major center of scientific research in the 3rd century BC. Two institutions established there during the reigns of Ptolemy I Soter (reigned 323 - 283 BC) and Ptolemy II Philadelphus (reigned 281 - 246 BC) were the Library and the Museum. Unlike Plato's Academy and Aristotle's Lyceum, these institutions were officially supported by the Ptolemies; although the extent of patronage could be precarious, depending on the policies of the current ruler.

Hellenistic scholars frequently employed the principles developed in earlier Greek thought: the application of mathematics and deliberate empirical research, in their scientific investigations.

In medicine, Herophilos (335 - 280 BC) was the first to base his conclusions on dissection of the human body and to describe the nervous system.

Geometers such as Archimedes (ca. 287 BC – 212 BC), Apollonius of Perga (ca. 262 BC – ca. 190 BC), and Euclid (ca. 325 BC – 265 BC), whose Elements became the most important textbook in mathematics until the 19th century, built upon the work of the Hellenic era Pythagoreans. Eratosthenes used his knowledge of geometry to measure the distance between the Sun and the Earth along with the size of the Earth.

Astronomers like Hipparchus (ca. 190 – ca. 120 BC) built upon the measurements of the Babylonian astronomers before him, to measure the precession of the Earth. Pliny reports that Hipparchus produced the first systematic star catalog after he observed a new star (it is uncertain whether this was a nova or a comet) and wished to preserve astronomical record of the stars, so that other new stars could be discovered. It has recently been claimed that a celestial globe based on Hipparchus's star catalog sits atop the broad shoulders of a large 2nd-century Roman statue known as the Farnese Atlas.

The level of Hellenistic achievement in astronomy and engineering is impressively shown by the Antikythera mechanism (150-100 BC). It is a 37-gear mechanical computer which computed the motions of the Sun and Moon, including lunar and solar eclipses predicted on the basis of astronomical periods believed to have been learned from the Babylonians. Devices of this sort are not found again until the 10th century, when a simpler eight-geared luni-solar calculator incorporated into an astrolabe was described by the Persian scholar, Al-Biruni. Similarly complex devices were also developed by other Muslim engineers and astronomers during the Middle Ages.

The interpretation of Hellenistic science varies widely. At one extreme is the view of the English classical scholar, Cornford, who believed that "all the most important and original work was done in the three centuries from 600 to 300 BC" At the other is the view of the Italian physicist and mathematician, Lucio Russo, who claims that scientific method was actually born in the 3rd century BC, to be forgotten during the Roman period and only revived in the Renaissance.