Science in classical antiquity
Thales of Miletus lived between 624 and 546 BC. He proposed that all things originated from water. This idea stood in stark contrast to the mythological stories told by his neighbors about how the cosmos came into being. Anaximander, who died around 546 BC, argued against Thales. He suggested a substance called the boundless instead of water. Anaximenes, active until 525 BC, returned to air as the primary element. He used simple experiments like breathing on one's hand to show how air could change through rarefaction and condensation. Heraclitus of Ephesus believed change was more fundamental than any specific substance. Fire played a central role in his theory of constant flux. Empedocles of Acragas combined earlier views. He claimed four elements existed: Earth, Water, Air, and Fire. These elements mixed and separated under forces he named Love and Strife. Leucippus and Democritus introduced atoms. They described matter as small indivisible particles moving through void space. Xenophanes of Colophon observed fossils of sea creatures. He concluded that earth and sea periodically mix to form mud.
Hesiod wrote Works and Days around 700 BC. His text regulated seasonal activities using star appearances and moon phases. By 450 BC, parapegmata texts compiled these observations for civil calendars. Greek medicine lacked a single licensed profession. Physicians competed with temple healers associated with Asclepius. The Hippocratic text On the Sacred Disease attacked rivals who attributed epilepsy to divine wrath. This author insisted on natural causes but offered vague treatments. Hippocrates of Kos lived from 460 to 370 BC. Tradition calls him the father of modern medicine. He used prognosis and clinical observation to categorize diseases. Most writings in the Hippocratic Corpus were attributed to him without justification. These texts influenced Islamic and Western medicine for over a thousand years. Temple healers and herb collectors all claimed qualification to treat patients. Public debate raged over disease causes and proper methods. Observations continued despite lack of consensus. Aristotle and Theophrastus later compiled works on animals and plants. Theophrastus classified minerals and rocks systematically. Pliny the Elder summarized this mineralogical work in Natural History.
Plato founded the Academy before 347 BC. He inscribed geometry requirements at its entrance according to later accounts. Plato believed material things reflected eternal unchanging ideas. Truth came through rational argumentation rather than empirical observation. Aristotle studied at the Academy until his death in 322 BC. He disagreed that truth was only found in abstract forms. Aristotle maintained the world is knowable through sensory experience. Directly observable things held reality while forms existed within matter or mind. He emphasized observation of material entities embodying forms. Mathematics played a secondary role compared to Plato's focus. Change took precedence over eternal ideas in his philosophy. Aristotle distinguished four causes: material, formal, efficient, and final. Final cause referred to purpose. Marine animal research at Lesbos showed organs served specific functions. Aristotle left the Academy after Plato died. He founded a school adjacent to the Lyceum. His physical theory included five elements: earth, water, fire, air, and aether. Light elements moved away from universe center. Heavy elements moved toward it. Celestial bodies made of aether moved in circles. Theophrastus succeeded him at the Lyceum. He wrote books on plant and animal life. Tourmaline attracted straws when heated due to pyroelectricity. Pliny referenced these mineral descriptions in Natural History.
Alexander the Great spread Greek thought across Egypt and Asia Minor. Alexandria became a major scientific center during the third century BC. Ptolemy I Soter ruled from 367 to 282 BC. Ptolemy II Philadelphus reigned until 246 BC. They established the Library and Museum with official support. Royal patronage enabled anatomical dissection. Herophilos lived between 335 and 280 BC. Erasistratus existed from around 304 to 250 BC. These men performed live dissections on condemned criminals under Ptolemaic rule. Herophilos reversed Aristotle's notion that heart was seat of intelligence. He argued for the brain instead. Erasistratus differentiated sensory and motor nerves linked to the brain. Euclid authored Elements between 325 and 265 BC. This work served as main geometry textbook until early twentieth century. Archimedes lived from 287 to 212 BC. He wrote treatises including Quadrature of the Parabola. Apollonius developed conic sections theory between 262 and 190 BC. Aristarchus of Samos proposed heliocentric model from 310 to 230 BC. Hipparchus discovered precession in second century BC. He cataloged 1020 stars. The Farnese Atlas statue bears a celestial globe based on his star catalog.
Pliny the Elder published Naturalis Historia in 77 AD. His compilation recorded explanations alongside material lists. He correctly described amber origin as fossilized pine resin. Trapped insects within samples supported this inference. Pliny provided eyewitness accounts of gold mining in Spain. His work survived Dark Ages and became standard reference for Renaissance scholars. Hero of Alexandria invented windwheel and aeolipile steam engine. Galen practiced medicine during second century AD. Around one hundred of his works survive today filling twenty-two modern volumes. Born in Pergamon, he studied under various philosophical schools. In 158 AD Galen served chief physician to gladiators. He studied wounds without human dissection. Living arteries contained blood contrary to dead animal theories. His error regarding ebb-and-flow motion became medical orthodoxy for thirteen centuries. Claudius Ptolemy lived between 100 and 170 AD. He wrote about astronomy, astrology, cartography, harmonics, and optics. Almagest systematized astronomical observations mathematically. Geography drew accurate maps using astronomical data. Harmonics and Optics included instructions for experimental instruments. Tables facilitated ease of data presentation. Ptolemaic system dominated celestial motion models until seventeenth century.
Antikythera mechanism dates from 150 to 100 BC. This thirty-seven gear mechanical computer calculated Sun Moon and five planet motions. It predicted lunar and solar eclipses based on Babylonian periods. Fragments of geared calendars attached to sundials appeared fifth or sixth century Byzantine Empire. Scientist al-Biruni described similar devices around 1000 AD. A thirteenth-century astrolabe contained clockwork mechanisms. Hero of Alexandria created earliest recorded steam engine called aeolipile. Syracusia construction demonstrated combining mathematical knowledge with technical expertise. Eratosthenes measured Earth size and distance to Sun between 276 and 195 BC. Archimedes approximated pi value in Measurement of the Circle. Sand Reckoner expressed very large numbers through new nomenclature. Hipparchus invented earliest known astronomical devices like astrolabe. These inventions reflected complex engineering traditions transmitted to later civilizations. Mechanical devices built during Middle Ages remained simpler than Antikythera mechanism yet followed similar principles. The legacy included both theoretical advances and practical applications across astronomy, mathematics, and medicine.
Common questions
When did Thales of Miletus live and what was his theory about water?
Thales of Miletus lived between 624 BC and 546 BC. He proposed that all things originated from water.
Who were the early Greek physicians and when did Hippocrates of Kos die?
Hippocrates of Kos lived from 460 BC to 370 BC. Tradition calls him the father of modern medicine and he used prognosis and clinical observation to categorize diseases.
What elements did Aristotle include in his physical theory and when did he die?
Aristotle died in 322 BC. His physical theory included five elements: earth, water, fire, air, and aether.
How many stars did Hipparchus catalog and when did he discover precession?
Hipparchus discovered precession in the second century BC. He cataloged 1020 stars which appear on the Farnese Atlas statue celestial globe.
When did Pliny the Elder publish Naturalis Historia and what did he say about amber?
Pliny the Elder published Naturalis Historia in 77 AD. He correctly described amber origin as fossilized pine resin with trapped insects supporting this inference.
What is the Antikythera mechanism and when was it created?
The Antikythera mechanism dates from 150 BC to 100 BC. This thirty-seven gear mechanical computer calculated Sun Moon and five planet motions.