Scientific Revolution
In 1543, during the era of religious wars that were waged between Protestants
and Catholics all over Europe, Nicolaus Copernicus's book, On the Revolutions
of the Heavenly Spheres, was published. This work is usually singled
out as the text that began the scientific revolution. Copernicus called
into question the geocentric Aristotelian-Ptolemaic system that had dominated
Medieval Europe, and he replaced it with a new heliocentric model. However,
it took more than 150 years for the new scientific system to congeal. Many
other scientist had to work out the specifics; they had to flesh out Copernicus's
new theory.
The individuals that took part in formulating the new theory of the universe
often met with harsh criticism. Their observations often conflicted with
the doctrines of the Catholic and Protestant faiths. Moreover, the new data
seemed to deny the obvious - that the earth was still and that the earth
set at the center of the universe.
Natural Philosophy Before 1500
For the following information on scientific thought before 1500, I have
relied upon Daniel J. Boorstin's The Discoverers and Wallace I. Matson,
A New History of Philosophy, Volume II, Modern. Both texts examine
the ancient and medieval worlds so that the reader might understand why
the scientific revolution was so revolutionary.
The Egyptian System
The Egyptians believed that the earth was flat. In the pharaohs tombs, we
can find caricatures of the sun-god Ra, riding his boat through the sky
during the day, and then riding another boat under the earth to his point
of departure for the next day. This myth explained the obvious to the Egyptians:
how and why the sun came up and set.
The Aristotelian System
Aristotle was a Greek philosopher who lived between 384-322 BC. His ideas
were lost to the West during the early Medieval period, but were rediscovered
in Europe in 13th century. Three theories of Aristotle are key for our discussion
of the early scientific revolution. In fact, the scientific revolution would
in large part be a refutation of these three Aristotelian principles:
1. Aristotle believed that the Earth was the center of the universe. He argued that its Matter (form and substance) was made up of four Primary Elements: earth, water, air, and fire.
Example of the elements within a piece of matter: Burning a piece of
wood
-Hardness of wood - earth
-When you burned the wood, this released the fire from wood
-Also, when you burned the wood, the smoke that resulted was said to be
a combination of water and air
Geocentric Universe
2. Aristotle made a clear division between the Earthly and the Celestial. He argued that the Celestial Heavens were made of "ether" a transparent, weightless, and pure material which contained all the heavenly bodies. The Celestial sphere, which began at the Moon and encircled the Earth, was perfect.
Aristotle's World View
3. Aristotle believed that the natural state of objects was rest. Motion
was possible only with the continuous contact of a mover. So, the Prime
Mover, God, set the above system into motion.
(Problem: How does an arrow shot from a bow continue to move after it leaves
the bow?)
The Ptolemaic System
Another Greek theorist, Ptolemy, lived between 90-168 AD. He believed that
the Heaven was spherical in form and rotated around the earth, which was
also spherical. The Earth was located in the middle of the Heaven. The Earth
did not rotate around the Sun or move in revolutions.
The Ptolemaic system came to dominate Medieval thought on the nature of the universe. Christians believed that the Earth was surrounded by a series of perfectly concentric crystalline spheres that revolved around the earth once every day. The fixed stars were connected to the outermost sphere, while the sun, moon, and five known planets were embedded in the inner spheres.
Christian Aristotelian-Ptolemaic Cosmos
From Peter Apian, Cosmographia (1524)
The Aristotelian-Ptolemaic understanding of the universe went well with Biblical teaching. There was a definite place for God, beyond the last sphere, who created and moved the entire project. Man, who was made in God's image, was at the center of the universe.
To account for the fact that the observed motions of the heavenly bodies did not mesh with the assumption that the spheres surrounding the earth were perfectly round, Ptolemy argued that the bodies were not located "directly on the great spheres whose common center was the earth but on smaller spheres rolling on the surfaces of the great spheres: the famous epicycles" (Wallace I. Matson, A New History of Philosophy, Volume II, Modern, 260).
The Problem with Ptolemy's View:
Inconsistency and the Epicycle
"It was obvious even to the ancients that the system would be greatly simplified if, instead of having the heavens rush around the earth every day, the earth itself should be supposed to revolve. This suggestion was known and discussed in the middle ages. It was rejected mainly on two grounds: a daily revolution of the earth still would not explain the motions of the planets and - the psychologically compelling reason - it is just obvious that the earth is at rest, that we are not standing on a body rotating at incredible speed. And some theologians pointed to the Biblical texts (Joshua 10:1 and Psalm 93:1, for instance) that assert the fixity of the earth" (Matson, A New History of Philosophy, Volume II, Modern, 260).
The Causes of Scientific Revolution
Why did the Aristotelian-Ptolemaic system come into question in the sixteenth century. What had changed? What new factors were at work in European life?
1. The Rise of Medieval Universities
2. The Expansion of Trade and Need for Exactness in Oceanic Navigation
3. Renaissance Humanism (the desire to glorify and understand the human and this life)
4. The discrepancy between everyday observations and the theory of Aristotle
and Ptolemy
Nicolaus Copernicus (1473-1543)
Copernicus was a Polish priest who studied math, astronomy, medicine, and theology in Renaissance Italy at the University of Padua. He spent 33 years preparing his book, De Revolutionibus Orbium Caelestium (On the Revolution of the Heavenly Orbs), for publication, but hesitated because he believed it might prove too radical for the Church. It was published in the year of his death: 1543.
Copernicus thought that the Ptolemaic system fit most observed heavenly acts, but that it did not "adequately provide for the required uniformity and circularity (of the heavenly spheres). A 'true' system by Copernicus' standards would not merely satisfy the eye but it would also have to please the mind" (Boorstin, Discoverers, 302). In short, it would be perfect. There would be no need for epicycles or constant recalculation.
Copernicus's revolutionary idea was that the sun, not the earth, was at the center of the universe. With his new heliocentric view, Copernicus's real goal was to fashion a system of simplicity. Heavenly motion was simpler to explain if the sun was at the center of the universe. Also, he could reduce the number of celestial spheres from 80 to 34.
The Universe of Copernicus
So, "Copernicus' objective was not to devise a new system of physics, much less a new scientific method. His single revision - a moving earth no longer in the center - leaves large features of the Ptolemaic system untouched. He stays with the doctrine of spheres, which was crucial to the Ptolemaic system, and avoids the debated question whether the celestial spheres were imaginary or real" (Boorstin, Discoverers, 298).
Although Copernicus was wrong - he thought that planets moved in a perfect
circle - it was his repositioning of the earth and sun that was so important.
Other scientists could work out the details that followed from the new breakthrough.
Tycho Brahe (1546-1601)
Tycho Brahe was educated at the Lutheran University of Copenhagen in all the liberal arts. His life-long love, however, was astronomy. After proving his competency as a great observational astronomer - Brahe found a new star in the Cassiopeia constellation - he was granted by King Frederick II, all the rents on the 2,000 acre island of Hven, in the sound between Denmark and South Sweden (Boorstin, Discoverers, 306). There, Brahe set up a scientific community in which he and his assistants rigorously calculated the movements of the planets and stars.
In his book, Progymnasmata (1602 ), he cataloged the positions of 777 stars, and by his death had done 223 more, making a total of 1000 stars.
By his death, Brahe's observations had far superseded the work of Ptolemy. Although his discovery of the new star in the Cassiopeia constellation called the Ptolemaic system into doubt (the celestial spheres in the Ptolemaic system were supposed to be perfect and unchangeable, where and how had this new one come from?), Brahe would not let go of the old astrological system.
He argued that he would not move to the Copernican view of the universe because his observations showed that the planets did not move in perfect circles around the sun.
Brahe came up with his own system. First, he kept the fixed earth at the center of the universe, and said that the sun circled around the earth. Next, he argued that "the other planets rotated around the sun following the sun's movement around the earth"(Boorstin, Discoverers, 308).
Tycho Brahe Universal System
from http://www.mhs.ox.ac.uk/tycho/catfm.htm
Johannes Kepler (1571-1630)
"On his deathbed Tycho Brahe bequeathed the voluminous records of his observations to a younger, more liberated, more erratic mind. He begged Johannes Kepler to translate them into improved astronomical tables. And he expressed his hope that Kepler would use the tables to prove the Tychonic (not the Copernican!) theory"(Boorstin, Discoverers, 308).
Kepler had been born in Wurttemberg, South Germany. His family was Lutheran, and he prepared for the ministry until he was twenty-two. It was then that financial considerations forced him to turn from the ministry to make money teaching math. In addition, Kepler began publishing astrological charts to bring in more funds.
In 1600, Kepler was hired by Brahe. The two men worked together for a year, and upon Brahe's death Kepler received all of his records.
In his new theorizing, Kepler tied his religious mysticism together tightly with his astrological views. He believed that God had created the universe, and that the universe was governed by the logical - "perfect" - laws of mathematics.
Although Kepler did not believe Brahe's theory on the nature of the universe was correct, he did use his data to prove that many of Copernicus's assumptions had been incorrect.
Galileo Galilei (1564-1642)
Galileo was born near Pisa in Italy. In 1585, he became a professor of mathematics at the University of Padua, just south of Venice. His first work was aimed at discovering the laws of falling bodies. Galileo disproved Aristotle's theory that the speed of an object's fall is proportional to its weight. He did this by dropping unequal weights from the Leaning Tower of Pisa. For this work, in 1592, Galileo was appointed the chair of mathematics at Padua, where he discovered the laws of falling bodies and of the parabolic path of projectiles.
In addition to his work at the university, Galileo also owned a small shop of his own, where he made instruments for surveying and navigation. In 1609, after hearing that a telescope - or as Galileo first called it a "spyglass" - had been constructed in Holland, Galileo set out to make his own. By August 1609, he had made a thirty power telescope, which he gave as a gift to the Venetian Senate. In return, they renewed his professorship at Padua for life, and increased his annual salary two fold.
"Early in January 1610 he did what now seems most obvious - he turned his telescope toward the skies. Today this would require neither courage nor imagination, but in Galileo's day it was quite otherwise. Who would dare use a toy to penetrate the majesty of the celestial spheres? To spy out the shape of God's Heaven was superfluous, presumptuous, and might prove blasphemous"(Boorstin, Discoverers, 318).
Galileo saw mountains and craters on the moon. He saw that the Galaxy, our Milky Way, was "nothing else but a mass of innumerable stars planted together in clusters." There were no crystalline spheres. In addition, Galileo discovered the four largest moons of Jupiter. Immediately, he published his findings in a book entitled The Starry Messenger, in which he declared his support for Copernicus.
Galileo's discoveries were scorned by other professors as heretical. In 1616, a Jesuit cardinal named Robert Bellarmine told Galileo that he must stop defending the Copernican theory that the earth moved. After years of silence, Galileo discussed the Copernican theory again in a new book he published in 1632. In 1633, Galileo was summoned to Rome by the Inquisition, and he was forced to stand trial for heresy. He was sentenced to life imprisonment, which was then commuted to permanent house arrest - he was forced to stay at his own home.
Galileo published his last book, Discourses Concerning Two New Sciences, in 1638. In it he honed many of his earlier arguments concerning the laws of motion.
It was not until 1992 that a papal commission acknowledged that an error
had been made in the prosecution of Galileo's case.
Isaac Newton (1642-1727)
Isaac Newton was born in Lincolnshire, England. He was educated at Trinity College at the University of Cambridge, and became Professor of Mathematics there.
His most famous work has been the Philosophiae Naturalis Principia Mathematica (Mathematical Principles of Natural Philosophy, 1687), in which he put forth his three laws of motion.
Scientific Method
The scientific method was formulated during the Scientific Revolution. It is based on two approaches, usually used in conjunction with one another: one empirical (inductive) and the other rational (deductive).
The New Scientific Attitude
The Scientific Revolution ushered in perhaps the greatest change of mind in human history. The confidence of men and women shifted from faith and tradition to the powers of reason. This shift had begun in the Renaissance, but reached a new level through the development of systematic sciences. Skepticism, an idea that the Medieval world would have frowned upon, became the scientific vogue.
In addition, scientists said they had found natural laws that were at work throughout the universe. These laws were within the reach of men and women who were willing to rigorously utilize their own capacity for reason.
Although the Christian God was obviously not dismissed from the lives of the new men and women of the scientific age, He had a different place in the world. For instance, Descartes attempted to use deductive reasoning to logically prove the existence of God. It seems the religious world and the scientific world were one community - however, what we will see in the developing modern era is the rapid expansion of the science with the concomitant decline of religion.