OLD ARISTOTELIAN IDEAS ABOUT UNIVERSE
Aristotle (384–322 BC)
Earth is at the center of an unchanging universe (geocentrism)
Planets and stars move around earth in perfect spheres
Day and night comes from universe rotating around earth every 24 hours
A heavenly abode exists beyond universe made of pure matter (ether)
The universe is put into motion by a perfect "prime mover" that "moves without being moved."
CHRISTIAN INTERPRETATION OF ARISTOTLE'S IDEAS
God is the Prime Mover
Earth is God's primary concern
Heavenly abode of angels exists beyond universe
Ptolemy (AD 100 –c. 170)
Planets move in small individual orbits ("epicycles") as they travel around earth
See also Ptolemy's map (below)
REASONS ARISTOTELIAN AND PTOLEMAIC IDEAS WERE QUESTIONED
Stressed idea that people should look beyond appearances (think of Plato's Cave)
All matter contained divine spirit.
Humans could understand the physical world by unlocking secrets through mathematical formulas
Sun transmits divine spirit
Discovery of New World
Need for new instruments for navigation
Disproved Ptolemaic geography
Printing press = spread of new ideas
Reformation = challenged religious authorities (Catholic Church) and emphasized personal study of Bible (hence, education and critical reading)
Support of rulers: for prestige, and desire for new tools of war
Religious leaders hoped to improve calendar to better date Easter
ASTRONOMY AND PHYSICS
Influenced by Neoplatonism and Hermetic doctrine
Convinced sun at center of universe (heliocentrism)
Earth is not stationary
Earth moves in perfect, divine, circles around sun
Day and night because of earth rotating on axis
Waited till year of his death to publish works in Latin - only read by a few scholars
Tycho Brahe (1546-1601)
Convinced King of Denmark to build him an astronomy lab on an island
Meticulously recorded detailed observations about movement of planets and stars over 20 years
Seen by naked eye (no telescope)
Discovered new star (1572) and comet (1577)
challenging Aristotle belief that sky was fixed
Believed earth at center of universe (geocentrism)
Johannes Kepler (1571-1630)
Worked for Brahe but believe in Copernican heliocentrism
1609-1619 developed three laws of planetary motion
Planets move in elliptical orbits around sun
Planets speeds varied according to their distance from sun
Relationships between planets can be measured mathematically
Introduced ideas to Galileo
Kepler served as official mathematician to Rudolf II in Bohemia
Galileo Galilei (1564-1642)
Conducted experiments to establish rules of physics (like object in motion stays in motion)
Improved and used telescope (invented by Dutch) to study skies
Saw that moon's surface was rugged and imperfect (like earth) not made of ether
Discovered Jupiter had moons and sun had spots
Published Dialogue of Two Chief Systems of the World in Italian not Latin (could be read by larger audience)
Promoted Copernican heliocentrism
Roman Inquisition tried to force him to renounce his views at trial
Defended his belief that the earth moved
Church put him under house arrest but his ideas spread
Galileo became court mathematition to Cosimo de Medici in Tuscany
Sir Isaac Newton (1642-1727)
Studied Copernicus and Galileo
Very religious - hoped to harmonize Christian beliefs with science
Developed three laws of motion
Inertia: Object at rest remains at rest, object in motion remains in motion unless acted upon by another force
Acceleration: Sum of forces on an object is equal to the mass of that object multiplied by the acceleration
Action/reaction: If one object exerts force on another object, the second object exerts equal and opposite force on the first.
Discovered laws of gravity which he applied to apples and planets
1687 published Principia (The Mathematical Principles of Natural Knowledge)
Brought astronomy and physics together and explained it through physical laws.
Newton became a member of Britain's Parliament and director of the Royal Mint
Rejection of humor system
Belief that imbalance in the humors -- blood, yellow bile, black bile and phlegm -- caused disease.
Illnesses cured by readjusting the humors, for instance, by bleeding patients.
Practiced by Greeks and Romans (including Hippocrates) until 15th century.
Believed in Hermetic doctrine
Said healers should look for truth not in books but in nature.
Concluded that all matter was composed of salt, sulfur and mercury (not earth, water, fire and air)
Looked for chemical imbalances to explain illnesses (instead of humor system)
Father of toxicology. (effect of chemicals on human body)
Andreas Vesalius (1514-1564)
Wrote first textbook on structure of human body based on observation On the Fabric of the Human Body (1543)
Challenged old assumptions about human anatomy
By dissecting cadavers
Became personal physician to Holy Roman Emperor, Charles V
William Harvey (1578-1657)
Dissected hundred of animals
Discovered that the heart (the spiritual center) works like pump pushing blood to circulate through body.
Became Royal Physician in England
Robert Boyle (1627-1691)
Irish nobleman, devout Anglican
Inspired by Galileo and Pacelsus
Searched for basic elements of matter.
Relationship between pressure and volume of a gas
If the volume of a gas is decreased, the pressure increases proportionally
Laid foundations for modern chemistry
Argued that matter composed of indestructible atoms that behave in predictable ways
Anton Leeuwenhock (1632-1723)
Chief pioneer in use of microscope.
First saw bacteria
"Little animals" in water, cheese, flour, mold, saliva etc.
That were 1000x smaller than creatures seen with naked eye.
DEDUCTIVE V INDUCTIVE REASONING
Deductive Reasoning (Aristotle, Descartes)
General to specific
Start with general statement, theory or hypothesis
All men are mortal (premise 1)
Socrates is mortal (premise 2)
Work way down to conclusion based on evidence
Therefore (ergo) Socrates is mortal
If conclusion is wrong it's because one of the premises are wrong
What thinks must exist (premise 1)
I am thinking (premise 2)
Therefore I must exist -- Cogito ergo sum (conclusion)
Inductive Reasoning (Francis Bacon, Novum Organum 1620)
Specific to general
Start with observation or facts (empiricism)
This bee has a stinger (fact 1)
That bee has a stinger (fact 2)
That bee has a stinger (fact 3)
The greater the data, the more accurate the result
To formulate a probable theory
Therefore all bees have stingers (probable conclusion)
Challenged by David Hume because presupposed facts not always true.
SCIENTIFIC REVOLUTION AND ROYALTY
Kings hoped sponsorship of science would give them prestige a powerful, educated people
Furnished laboratories and subsidized scientists.
Hoped scientific inquiry would yield practical discoveries
Better navigation and map making
Royal Societies (second half of 17th c.)
Charles II chartered Royal Society in England
Louis XIV (under finance minister Jean-Baptiste Colbert) founded Academie des Sciences in France.
Government support added prestige and legitimacy to science.