The Scientific Revolution
c.
Late 16th Century – 18th Century
Background and Astronomers
What caused 17th c. thinkers to challenge the medieval view of the world?
·
Some possibilities:
o Discovery
of the New World
o Invention
of the Printing Press
o Rivalry
Among Nation-States
o Reformation
o Renaissance
Humanism
Discovery of the New World
·
The period of exploration and conquest led to the
discovery of new plant and animal life and possibly encouraged greater interest
in the natural sciences.
·
The traditional link between navigation and astronomy and
the great advances made by Portuguese navigators in the 15th c.
helped fuel an interest in learning more about the stars
Invention of the Printing Press
·
Scientific knowledge could spread much more rapidly
because of the printing press.
·
By the second half of the 17th c.
there were numerous books/newsletters keeping people informed about the most
recent scientific discoveries.
·
This allowed Thomas Hobbes in England to be cognizant of
the discoveries coming out of Italy.
Rivalry Among Nation-States
·
The constant warfare may have pushed scientific
development by placing an increasing importance on technology, or applied
science.
·
In China, by comparison, a land previously ahead of
Europe achievement-wise, the lack of external threat may have helped create a
complacency that stood in the way of scientific and technological advancement.
Reformation
·
The Protestant Reformation, by encouraging people to read
the Bible, did help create a larger reading public.
·
Although Luther, Calvin, and the like were not interested
in challenging the traditional scientific worldview, their opposition to the
religious hegemony of Rome did provide a powerful example of challenging
established authority.
Renaissance Humanism
·
Humanist interests in the writings of the classical world
also extended to the scientific texts of the ancient Greeks.
·
Certain ancient texts were rediscovered in the
Renaissance. Although their ideas were ultimately rejected by the Scientific
Rev., this basic familiarity with the past was a necessary stage in order for
modern scientific thought to mature
Medieval Worldview Prior to the Scientific Revolution
·
A synthesis of Christian theology with the scientific
beliefs of the ancient authors
·
Thomas Aquinas
(1225-1274): Took the works of Aristotle and harmonized them with the teachings
of the Church.
·
Knowledge of God was the supreme act of learning, through
both reason & revelation
·
Value of science was to better understand the works of
God
Aristotle’s Influence…
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Material World made up of four elements: earth,
air, fire, and water. Gives rise to…
·
Alchemy – the perfect compound of the
four elements in perfect proportion. Less perfect metals (lead) might be
transformed by changing the proportion of the elements.
·
The Four Humours (of
medicine): blood, phlegm, yellow bile, and black bile. Excess of any one
produced one’s essential personal characteristics
Ptolemy’s Beliefs (c. 85-165 A.D.)
·
The Ptolemaic system placed Earth as a stationary object
around which heavenly bodies moved, while the stars were fixed in their orbits.
·
One problem: How do you explain the motion of the planets
in relation to the fixed stars? At times planets appeared to be moving
backwards.
o To
cope, epicycles—planetary orbits within an orbit—were added to the
system
The Revolution in Astronomy
·
Nicolaus Copernicus and the
Heliocentric Theory
·
Tycho Brahe and Astronomical
Discoveries
·
Johannes Kepler and the Laws of
Planetary Motion
·
Galileo Galilei and Proof of the
Heliocentric Theory
·
Sir Isaac Newton and the Law of
Universal Gravitation
Copernicus and the Heliocentric Theory
·
Presented the first serious challenge to geocentric
theory, when he hypothesized that the sun was at the center of the
universe
·
and that the earth moved in a circular
·
orbit around the sun. (However,
·
does not eliminate epicycles.)
·
Published Concerning the Revolutions of the
Celestial Spheres (1543). Other scientists and Protestant &
Catholic churchmen denounced his theory, calling it illogical, unbiblical, and
un-Christian.
Tycho Brahe (1546-1601)
·
A Danish astronomer with no social life, as he had lost
part of his nose in a duel and rebuilt it with a prosthetic made of silver and
gold alloy.
·
While he did not believe the Ptolemaic system, neither
did he accept Copernicus’ views. So he proposed a system in which the moon and
sun revolved around the Earth, while the other planets revolved around the sun.
Johannes Kepler (1571-1630)
·
The
Laws of Planetary Motion
o Brahe’s
student, he accepted the heliocentric theory
o Law 1:
§
The planets, including the earth, revolve around the sun
in elliptical (rather than circular) orbits
o Law 2:
§
The velocity of the planets varies according to their
distance from the sun. A planet moves faster when it is closer to the sun than
when it is far away.
o Law 3:
§
Sets forth a complex mathematical formula explaining the
physical relationship among the moving planets.
Galileo Galilei (1564-1642)
·
An Italian mathematician, astronomer, physicist, &
believer in the heliocentric theory
·
He was the first to use a telescope for astronomical
observations. He discovered the mountains on the moon, the moons of Jupiter,
the rings around Saturn, and sunspots.
·
But most importantly, he could provide decisive support
to what others had only hypothesized: that the•Following the
publication of his Dialogues on the Two Chief Systems of the World
(1632), the Catholic Church began to condemn Galileo’s work.
·
Galileo contended that the Bible was not a reliable
authority on scientific matters. The Church would only tolerate the
heliocentric theory as hypothesis, not as fact.
1633-The Roman Inquisition condemned Galileo’s work and placed it on the Index of prohibited books.
·
planets revolve around the sun.
·
Galileo was compelled to recant, although he is said to
have muttered,
“And yet it
does move.”
·
Confined to house arrest for the rest of his life, he
continued his scientific work, concentrating on less controversial subjects.
o His
study of falling bodies disproved Aristotle’s contention that objects fall at
varying speeds, depending on their weights.
He developed the theory of the pendulum and discovered the principle of inertia
Sir Isaac Newton (1642-1727)
·
Even with the work of Copernicus, Kepler, and Galileo,
there was one unanswered question:
“What is it that causes the
planets, stars, and other heavenly bodies to move in an orderly fashion?”
·
Newton worked for almost 2 decades on the
problem before he published Principia Mathematica
in 1687.
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Galileo’s work on motion influenced Newton.
Newton wondered what force kept the planets in an elliptical orbit around the
sun, when theoretically they should be moving in a straight line.
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Supposedly Newton saw an apple drop from a
tree and deduced that the same force that drew the apple to the ground may
explain planetary motion. Newton finally posited that all the planets and
objects in the universe operated under the effects of gravity.
·
In Principia, he set forth the Law
of Universal Gravitation, which provided a mathematical explanation of the
operation of gravity everywhere in the universe.
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Newton was an extremely religious man and often wondered
why, when he delivered public talks, his audiences were more interested in
scientific discoveries than in theology.
·
He spent a great deal of time making calculations of
biblical dates and practicing alchemy.
·
More importantly, he began to experiment with optics,
thus making the study of light a new scientific endeavor. He showed that white
light was a heterogeneous mixture of rays rather than pure lights.
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And, sorry! Newton is also the father of differential
calculus.