The Greeks were not the first to watch the sky or to count: Egyptians and Babylonians already had advanced mathematical and astronomical knowledge. The Greek novelty was the idea of explaining phenomena by natural causes and proving statements by reasoning. The modern scientific method has its roots here.
- c. 585 BCThales of Miletus, tradition says, predicts a solar eclipse.
- 6th century BCPythagoras and his school study numbers, geometry and music.
- c. 430 BCDemocritus proposes atomic theory.
- c. 400 BCHippocrates of Kos founds rational medicine.
- 4th century BCAristotle studies logic, physics and biology.
- c. 300 BCEuclid writes the Elements in Alexandria.
- c. 270 BCAristarchus of Samos proposes that the Earth goes round the Sun.
- c. 250 BCArchimedes discovers the principle of buoyancy and calculates pi.
- c. 240 BCEratosthenes measures the Earth's circumference.
- c. 150 BCHipparchus compiles a star catalogue and discovers the precession of the equinoxes.
- 2nd-1st century BCThe Antikythera mechanism is built.
- 1st century ADHero of Alexandria describes steam engines and automata.
- 2nd century ADPtolemy writes the Almagest; Galen systematises ancient medicine.
Mathematics
Thales is said to have measured the height of the pyramids by comparing their shadow with a stick's. Pythagoras and his followers linked number, geometry and music. Euclid's Elements, written in Alexandria around 300 BC, build all of geometry from a few postulates: the most used mathematics textbook in history, until the 19th century. Archimedes calculated areas and volumes with methods anticipating integral calculus.
Astronomy and geography
| Scientist | Contribution |
|---|---|
| Anaximander | First map of the known world; the Earth floating in space |
| Aristotle | Evidence for a spherical Earth from its round shadow in lunar eclipses |
| Aristarchus of Samos | The Sun at the centre: a heliocentric system 1,800 years before Copernicus |
| Eratosthenes | Measured the Earth's circumference by comparing shadows at Alexandria and Syene, close to the true value |
| Hipparchus | Catalogue of about 850 stars, discovery of the precession of the equinoxes |
| Ptolemy | The Almagest (geocentric model) and Geography, the basis of astronomy for 1,400 years |
Medicine
Hippocrates, born on Kos around 460 BC, separated medicine from magic: diseases have natural causes, and doctors must observe the patient's symptoms, diet and environment. The Hippocratic Oath, in modern form, is still taken by doctors. In Alexandria Herophilus and Erasistratus dissected human bodies, discovering nerves and studying the brain. Galen, a Greek physician in 2nd-century Rome, wrote works that dominated medicine until the Renaissance.
Technology
The Greeks built water clocks, lighthouses, cranes and aqueducts such as the Tunnel of Eupalinos on Samos, dug from both ends and meeting almost perfectly. Hero of Alexandria described the aeolipile, a sphere spun by steam, temple doors that opened by themselves and coin-operated holy water dispensers.
Legacy
Greek scientific works were translated into Arabic in Baghdad and studied and enriched in the Islamic world; they returned to Europe in the Middle Ages and Renaissance. Words such as mathematics, geometry, astronomy, physics, biology and technology are all Greek.
See also Greek philosophy and Aristotle.