greek ontologies

Greek Ontologies• Democritus, atoms discrete (things in void)• Aristotle, continuum, (stuff, no void)• Zeno’s paradox continuum vs discrete (presages wave

vs particle)• Aristotle’s World made of earth, air, fire and water

[fifth element=ether] Moved downwards and straight, Not perfect. Earth not moving but at center

• Celestial objects were made of an exalted substance formed in spheres which move in circles above

• Time flows regularly, space is not a void• Astrology mixed with Astronomy

PTOLEMY fl 140

• Mathematician, astronomer,• Nested spheres with earth at center, a sphere

but not rotating• Added epicycles• Written in Greek, Preserved in Arabic ,

translated to Latin 12th century• View persisted till Copernicus

Copernicus fl1520

• Canon of the Church, astronomer, physician, math, law, languages, classics

• New theory to explain celestial findings published just prior to his death (heliocentric with rotating earth)

• Not persecuted as his predictions worked, theory based on assumptions

Measuring Stellar Angles

Tyco Brahe fl1580

• Huge data set based on improved methodology including revived use of trigonometry and daily observations

• More accurate data

• Kepler was his assistant

Kepler fl1600

• Observed supernova of 1604• Studied orbit of Mars• Able to use Napier’s logarithms• Able to use Brahe’s data• Developed laws of planetary motion

Galileo fl1630

• Refracting telescope developed in Netherlands in 1608

• Galileo improved technology• Observations converted theory to fact• Galilean relativity (velocity relative to

reference points, moving ship - dropped ball)• Laws of Nature same in all inertial frames

Newton fl1665

• Physicist, mathematician, alchemist, Master of the Mint

• Developed reflecting telescope, light is particulate (corpuscle)

• Development of calculus (concurrently but independently of Leibniz)

• Laws of Motion & Gravitation [no delay] based on idealized center of mass [gravity]

Newton’s Ontology

• Absolute space• Absolute time• Galilean relativity• Light consists of particles (corpuscles)• Action at a distance [instantaneously]

Determinism

• Laws of motion are clocklike and in principle reversible.

• Laws of motion explained Kepler’s laws of planetary motion

• Future is predictable on basis of the iteration of laws on the current state(s)

THEMES

• CREATION OF MODELS, MENTAL VS REAL; EMPIRICAL VS FORMAL IDEALS

• MODELS PREDICT AND EXPLAIN• IMPROVED OBSERVATIONS THROUGH IMPROVED

TECHNOLOGY MODIFY MODELS• IMPROVE ANALYSES THROUGH MATHEMATICAL

ADVANCES• IDEALS VS MATERIAL; CAUSALITY; TIME; SPACE;

MOTION;