history 311 the scientific revolution part ii. plato and aristotle matter and form potentiality and...
TRANSCRIPT
Plato and Aristotle
Matter and Form
Potentiality and Actuality
Actuality is the fulfillment of the end of the potentiality
Five ElementsEarth, Air, Fire, Water, Aether
Fire – Hot & DryEarth – Cold & DryAir – Hot & WetWater – Cold & WetAether – Divine Substance
Ptolemy
16th Century Illustration of Ptolemy (2nd century)
Using Quadrant to Measure Angle Of Star Altitude
Uranius, Muse of Astronomy, in Background
Humoral Theory – Influence of Galen
and Arabs Basic Humors
– Blood (hot) , Phlegm (cold), Yellow Bile (dry), Black Bile (wet)
Material Substances– Earth, Air, Fire,
Water
Theory of Temperament
PessimisticWet, Black Bile
CholericDry, Yellow Bile
Sanguine,Hot, Dry Blood
Plegmatic,Cold, Wet phlegm
Giordano Bruno1548-1600
Plurality of Worlds
Infinite Universe
Rotation of the Earth
Infinite Universe of Four Elements
Burned at Stake in 1600
Tycho Brahe1546-1601
Uraniborg Observatory in Denmark
Supernova of 1572
Great Comet of 1577
Brahe’s Notebook on Comet
Johannes Kepler1571-1630
Astronomer and Astrologer
Emphasis on Mathematics
Accepts Heliocentric View
Elliptical Obits
Laws of Planetary Motion
Rejects Copernican View ofPerfect Orbits
The orbit of every planet is an ellipse with the sun at one of the foci. Thus, Kepler rejected the ancient Aristotelean, Ptolemaic,and Copernican belief in circular motion.
A line joining a planet and the sun sweeps out equal areas during equal intervals of time as the planet travels along its orbit. This means that the planet travels faster while close to the sun and slows down when it is farther from the sun. With his law, Kepler destroyed the Aristotelean astronomical theory that planets have uniform velocity.
The squares of the orbital periods of planets are directly proportional to the cubes of the semi-major axes (the "half-length" of the ellipse) of their orbits. This means not only that larger orbits have longer periods, but also that the speed of a planet in a larger orbit is lower than in a smaller orbit.
Kepler’s Three Mathematical Laws of Planetary Motion
William Gilbert1544-1603
Gilbert’s terrellaWork on Magnets
Galileo Galilei
1564 - 1642
Starry Messenger , 1610
Dialogue Concerning the Two Chief World Systems, 1632
1857 Painting by Christiano Banti of Galileo Before the Roman Inquisition
Actual Trial in 1633