Astronomy The Greeks

Archaic

Thales, anaximander, pythagoras

classical

socrates, plato, aristotle

Hellenistic

aristarchus, archumedes, eratosthenes

Thales

theoretical models

‘all things are matter’

Earth = disk

predicted solar eclipse

Anaximander

student of Thales

scientific experiment

gnomon

infinity

mechanical model

earth = floats in infinity

inhabited portion = flat

sun + moon = rings with fire

Pythagoras

geometry

‘cosmos’

morning + evening star = venus

sphere earth

five solids

Anaxagoras

moon = sphere made of matter

sun = hot stone

impiety —> imprisoned

Empedocles

air = finely divided matter

four elements

Leucippus and Democritus

atomic theory

matter = indivisible particles

milky way

Plato

Student of socrates

dialect method

metaphysics

academy of athens

circular motion ‘perfect and eternal’

timaeus

five solids

• tetrahedron

• cube

• octahedron

  • icosahedron

Eudoxus

Student of plato

figure eight

spheres

Aristotle

student of plato

alex the great

transit of venus

order of spheres

motion in heavens

elements

aether

moon boundary

first spherical earth

shadow of earth is round

Aristarchus

Geometry = measure dist to sun + moon

sun = center of universe

parallax

first and third quarter of moon to est. dist. of sun + moon

right triangle

sun = 400x larger than moon

size of earth shadow during eclipse

Eratosthenes

Geography

zenith

circum. of earth

cyrene —> tropic of cancer

Hipparchus

year length

full moons

cataloged stars

procession of axis

star brightness

epicycles

retrograde

Ptolemy

geocentric

retrograde

cartographer

almagest - all known astronomy

epicycle —> deferent, deferent —> equant

Antikythera

shipwreck

bronze gears

happarchus?

analog computer