Unit 1 – Renaissance and Rebirth

1.5 – THE SCIENTIFIC REVOLUTION

PART ONE: THE CULTURE OF SCIENCE

Introduction: Medieval and early modern European scholars viewed questions about the world and science as primarily a religious and/or theological issue. Religious teaching permeated all thought and activity. An example is the political theory of Divine Right. Religious teachings dominated all aspects of life, from marriage and divorce even to eating habits. However, as Europeans, particularly the upper classes, became more economically secure and better educated, their view of the world became decidedly more secular if not completely scientific. This change was primarily the result of the Scientific Revolution, a time when modern science based on the union of experimental observation and sophisticated mathematics emerged.

Western civilization is the only civilization to develop modern science. One historian has gone so far as to state that the Scientific Revolution was "the real origin of the modern world and the modern mentality." Unquestionably, its scientific achievements more than any other element have set Western society apart.

The Medieval Legacy: Up through the early sixteenth century, the ideas of Aristotle still dominated Western scientific thinking. Aristotle had been lost to the West, but with the capture of Toledo, Spain from the Muslims in 1095, knowledge of Aristotle was re-established. The great thinkers of the day found Aristotle’s ideas in harmony with the teachings of the Bible, and therefore considered them infallible. A prime example is Aristotle’s distinction between the substance of a thing and its appearance, its accidents. This distinction led the Fourth Lateran Council to adopt a new technical term: Transubstantiation. Supreme irony that it may appear, the "Arabized" Aristotle became the presiding genius of the created (Western Christian) world.

Medieval education was "scholastic," that is, academic, and all important writers of the period were "scholastics." Hence, scientific thinking of the period was called Scholasticism, the combination of the Bible and Aristotle. Education was aimed more at refining existing thought than breaking new ground. Experimentation was discouraged. Medieval Universities were set up in which students followed a prescribed course of study upon completion of which they were awarded degrees which certified to their proficiency. Lessons consisted of lectures and textbooks which frequently had to be shared by several students since they were expensive.

Aristotle had prescribed that the earth sat motionless at the center of the universe, and was surrounded by eight transparent crystal spheres which moved around it. In these spheres, the moon, sun, and five known planets were embedded. The stars were also embedded in these spheres, and considered to be fixed in space. These spheres were hierarchical, and became purer as one traveled further out the cosmos. Since in reality the stars move, and their position in the sky changed over time, medieval thinkers, rather than question Aristotle’s thinking, added two more spheres to accommodate the change in position. Beyond the tenth hemisphere, according to medieval thinkers, was heaven where the throne of

God and the souls of all the saved existed. The ten spheres were kept in perfect motion by angels.

Aristotle’s teachings about astronomy and physics were accepted, with minor revisions, for almost two thousand years. Since his conclusions were based on visual inspection, they were a common sense, (and therefore understandable) explanation for that which the eye saw. Also, medieval philosophers found Aristotle’s teachings in tandem with those of scripture. It put human beings, God’s greatest creation, at the center of the universe. It also established a physical location for God and heaven. Human beings were at the center of a "great chain of being" that reached from the throne of God to the lowliest form of visible life on earth. Explanations of scientific questions were always considered in light of God’s "perfect creation."

The Medieval church neatly divided the entire universe into two camps: good and evil. The earth was heavy, weighed down with corruption and sin as well as its own weight. Angels, who were essentially weightless beings, existed in heaven, outside the farthest sphere. The goal of humankind was to attain the lightness of heaven by freeing oneself from the weight of sin.

The medieval geocentric theory placed the Earth in the center of the Universe.

Aristotle’s ideas were supplemented, and partially explained in the second century A.D. by a Greek astronomer, Claudius Ptolemy who published a massive work known as the Almagest, (Arabic for "greatest.) Ptolemy described the Quadrant, and other instruments which the Arabs had invented, and tried to measure the orbits of the sun, moon, and planets. He accepted Aristotle’s position that the earth was surrounded by the spheres, and that the most distant sphere contained the furthest stars, which Ptolemy believed to be fixed points of light. He also believed that the planets traveled in spherical orbits, but since observation did not bear this out, he determined that there were minor variations in the orbits, which he called "precession." This precession made it possible to explain, and predict, the movements of heavenly bodies even though that movement did not appear to be a perfect sphere.

The thinking of Aristotle and Ptolemy was adopted by Dante Alighieri in the Divine Comedy. In the Inferno, Dante and the Roman Poet Virgil, travel to the core of the earth where they find hell. They then climb out the other side, in the Southern Hemisphere, where they find Purgatory, (Purgatorio) and finally ascend to the tenth sphere where they find heaven. Paradiso)

CAUSES OF THE SCIENTIFIC REVOLUTION

The discovery of the laws of science and physics and workings of the universe were rewards per se for the work required to produce them; yet there were deeper underlying causes of the Scientific Revolution:

1. The contributions to science by medieval thinkers were much more considerable than scholars were once willing to believe. It had been all too easy to dismiss medieval thinking as typical of the "dark ages," a period of suspicion and thinking locked in tradition. Universities had established departments and professorships in philosophy as early as 1300. These professorships were entirely independent of theological studies. Scholars of philosophy had begun the process of inquiry, an attempt to derive meaningful conclusions about the nature of the world. In that regard, it might be more correct to speak of a Scientific Evolution, rather than a Revolution.

Science emerged from this process as a minor, but very distinct branch of philosophy. Universities established professorships in mathematics, astronomy, and physics (natural philosophy) within their philosophy departments. The great thinkers of the Scientific Revolution, including Galileo and Newton, were products of these universities. Although their theories and postulations constituted a departure from accepted notions, they were equally a product of those accepted notions.

2. Renaissance thinking stimulated scientific progress. Medieval science was limited by its own system of mathematics which was rudimentary at best. Renaissance humanist’s obsession with classicism led to the recovery of ancient Greek mathematics. The discovery of classical mathematical treatises revealed that the scholars of antiquity often differed with one another. It fell to modern thinkers to resolve these differences. Additionally, Renaissance patronage often financed the work of scientific scholars. A prime example is Galileo, whose work was financed by the Medici family.

3. The need for precise navigational instruments for trans-Atlantic voyages was also a factor. Sea Captains needed accurate instruments to measure the distant coastlines where they landed. Sir Thomas Gresham, an English financier left a large sum of money to establish Gresham College in London with the stipulation that three of its seven professorships concern themselves with scientific subjects. The professor of astronomy was directed to teach navigation to his students. The result was a seventeenth century ballad about the college’s mission:

      This college will the whole world measure, Which most impossible conclude,      And navigation make a pleasure, By finding out the longitude.

Navigational problems were the motivational force behind the invention of such useful instruments as the telescope, barometer, thermometer, pendulum clock, microscope, and air pump.

Science Flourishes:   Scientific culture gradually spread eastward, and by the 1660’s, scientists conversed and corresponded with each other on a regular basis. Lectures, meetings, and professional scientific associations soon sprang up. In 1662, King Charles II chartered the Royal Society of London for Improving Natural Knowledge. Its members included Edmund Halley, the astronomer who discovered the actual movement of the stars and discovered the comet that bears his name. It also included John Locke, and Christopher Wren, the architect who rebuilt a number of London’s churches after the great fire of 1666. Newton dedicated his Principia to the Royal Society. The society adopted as its motto the words of the Roman Poet Horace:The

words are the words of a master, but we are not forced to swear by them. Instead we are to be borne wherever experiment drives us A French Academy of Science was also formed, but it its membership lacked the formality of the British society, and much time was spent eating and drinking, and very little in scholarly discourse.

Latin had long been the language of the church and of science, but with the Scientific Revolution, more and more scholarly works were written in the vernacular of the author. Sir Isaac Newton was the exception, who preferred to write in Latin so that scholars in other countries could read his work. Galileo wrote in Italian.

The Scientific Revolution never flourished in Eastern Europe as it had in the West. Theological and devotional literature dominated universities and libraries. As a result, Eastern Europe has been remembered more for its music than for its science. The Russian Orthodox Church denounced secular knowledge and experimentation as heresy and the work of the antichrist. This fact, coupled with the fact that the Renaissance never reached Russia, kept the country from participating in the new era of science. The sole exception was the work of Peter the Great who after his trip to Western Europe wished to refute the Western view that "we are barbarians who disregard science." He promoted some scientific research, but it was all for practical purposes, such as shipbuilding and improving artillery.

The Scientific Revolution appeared to force theology and religion into the background. Although the scholars of the time did not doubt the existence of God, or His creation of the Universe, they saw him as impersonal and uninvolved. Descartes had implied that humanity could live independently of God. He got into hot water with church officials because his writings seemed to deny the existence of God. There was no question that the role of religion and of the Deity was suddenly a matter of debate. John Donne, the English poet wrote in 1612, "The new philosophy calls all in doubt.

PART TWO: COPERNICUS TO GALILEO LOOK TO THE STARS

The Work of Copernicus: There were some early challenges to Aristotle’s thinking, primarily his ideas on a perpetual state of motionlessness. Archimedes of Syracuse (c. 287 – 212 B.C.E.) had challenged Aristotle’s notion that rest was the natural state for an object, and that an "active mover" was needed to generate motion. Nicholas of Cosa, (1401-1464) had speculated that the earth might actually be in motion. Leonardo da Vinci also speculated that the earth might move around the sun. None of these theories went beyond speculation, however; no attempt was made to explain or prove its validity mathematically.

The first major departure from Aristotle’s thinking was the work of Nicolaus Copernicus (1473 – 1543). Copernicus was born in Poland, and as a young man had studied church law and astronomy at a number of European universities. At the time of his study, the teachings of Aristotle as modified by Ptolemy were still considered unimpeachable. The pseudo-science of astronomy, the belief that the position of the stars influenced the future, was prevalent.

Copernicus considered Ptolemy’s calculations to be cumbersome, if not inaccurate. To him, the idea of a heliocentric universe was more sensible. This idea was not new to him; a number of ancient Greek scholars (Aristotle being the notable exception) had also hypothesized that the earth and planets revolved around the sun. This idea had gained new interest in Renaissance Italy, although it was primarily a matter of intellectual speculation. Copernicus worked on his ideas from 1506 to 1530, but never questioned Aristotle’s belief in crystal spheres or that a circular motion was almost perfect and therefore divine. In fact, his own conception of the solar system, although heliocentric, shows the planets revolving around the sun in perfect circular orbits, like the grooves on a CD. He accepted Aristotle’s idea that the spherical universe was finite, and that it was perhaps limited by the stars which he considered fixed. He believed that the movement of the stars was caused by the earth’s rotation. He

made some serious errors in his calculations, and did not appear interested in carrying on his observations. He also could not explain why there was no constant wind from the east, as he assumed (incorrectly) that the earth moved to the east in its revolutions around the sun. He did however, conclude that the earth rotates on its axis once a day and revolves around the sun every 365 days.

In the middle of all this sits the Sun enthroned. How could we place this luminary in any better position in this most beautiful temple from which to illuminate the whole at once?

Copernicus also suggested that his astronomical theories could be proven mathematically. He published his findings in his major work, On the Revolutions of the Heavenly Bodies. However, he did not wish to invite ridicule from the established scientific community, and therefore did not publish it until 1543, when he was on his deathbed. Ironically, Copernicus dedicated his work to the Pope; he seemingly was unaware of the intense theological debate his work would generate.

The repercussions of Copernicus’ theories were as vociferous as was the shock they created. His theories suggested that the universe was considerably larger than had once been thought. If he were correct, the universe would be infinitesimally gigantic. Also, by making the earth just another planet in the solar system; a mere player rather than the star attraction, he completely nullified Aristotle’s argument that the earth was different from the other heavenly bodies. His ideas left no place for perfection, or for heaven and the throne of God.

Observation of the sky had almost as much affect (if not more) in changing thoughts about the nature of the universe as had Copernicus’ writings. In 1562, a "new star" appeared, and shone brightly for two years. It was in reality a distant exploding star. Also, in 1577, a hitherto unknown comet appeared which cut a straight path across the presumably impenetrable spheres of the heavens. Nature itself seemed to be moving to prove Aristotle and Ptolemy wrong.

Johannes Kepler   (1571 – 1630) was another astronomer named Tycho Brahe’s assistant. He had been trained for the Lutheran ministry, and was a thoroughly medieval figure. His mother practiced astrology, and was condemned to be burned at the stake, but he managed to save her through a convoluted legal process. Kepler was something of a mystic, who claimed that he had correctly predicted a harsh winter, and peasant uprisings in Germany. He believed that the universe was built on "mystical mathematical principles," and there was a certain musical harmony that existed between the heavenly bodies—literally, "the music of the spheres." Kepler faced persecution from Lutherans because of his views and was protected by Jesuits when he fled to Austria, but had to leave that country when he refused to convert to Catholicism. Brae from his deathbed implored Kepler to continue his work, and the Holy Roman Emperor, Rudolph II, appointed Kepler as imperial mathematician. Kepler reworked and reanalyzed Brae’s data and eventually formulated three important laws of planetary motion, most notably that the orbits of the planets were elliptical rather than circular, which dispelled Aristotle’s notion.

Kepler managed to prove mathematically the precise relationship between the sun and planets. His work completely destroyed the old Aristotelian and Ptolemaic theories of the universe. He came close to, but did not demonstrate, the law of universal gravitation. His conclusions also indicated that the hand of God was not needed to move the planets along in their orbits, which brought him into serious conflict with the position of the church.

Galileo:   Galileo Galilei was born to a poor but noble family in Florence, Italy. He was fascinated by mathematics, and was demonstrably brilliant. He became professor of mathematics in 1589 at the age of twenty five. Although he did not theorize it, Galileo was one of the first to employ the modern scientific method, in that he conducted experiments to determine what would happen. His most famous experiment demonstrated the law of acceleration: a uniform force (gravity) would produce uniform acceleration. Two objects in a vacuum would fall at the same speed regardless of weight or volume.

In his Two New Sciences, Galileo demonstrated his conclusions:

A piece of wooden moulding…was taken on its edge was cut a channel a little more than one finger in

breadth. Having made this groove very straight, smooth and polished, and having lined it with parchment, also as smooth and polished as possible, we rolled along it a hard, smooth and very round bronze ball…. noting….the time required to make the descent….we now rolled the ball only one quarter the length of the channel, and having measured the time of the descent, we found it precisely one half of the former….In each experiment [over many distances], repeated a full hundred times, we always found that the spaces traversed were to each other as the squares of the times, and this was true for all inclinations of the plane.

Galileo also formulated the law of inertia. The natural state of an object was not rest, but motion. An object would remain in motion unless stopped by a superior force. This was completely opposite Aristotle’s theory, which was not completely discredited. He also postulated that the air and clouds of the earth move as it rotates, although they appear stable to an observer on the surface of the earth. Galileo’s rooms for experimentation in his house became the first true scientific laboratory.

He also became interested in astronomy, built his own telescope, and discovered four moons rotating the planet Jupiter. The presence of the moons also discredited Aristotle’s argument that the planets moved inside an impenetrable crystal sphere, and further verified the theories of Copernicus. Galileo also observed the rings of Saturn, and observed sun spots as they moved across the surface of the sun, which suggested to him that the sun itself also rotated on an axis.

Galileo often sought practical information from craftsmen and artisans. He consulted workers who built cannon, soldiers, and people who made compasses, astrolabes, navigation instruments, even water pumps. He did not care whether his work reached ordinary people, but believed that "the mobility of the earth is a proposition far beyond the comprehension of the common people." He said that the "all too common vulgar" should remain ignorant of his findings, "lest they become confused, obstinate, and contumacious."

In Siderius Nuncius (the Starry Messenger), Galileo described his finding when he viewed the moon through his telescope:

I feel sure that the moon is not perfectly smooth, free from inequalities and exactly spherical, as a large school of philosophers considers with regard to the moon and the other heavenly bodies. On the contrary, it is full of inequalities, uneven, full of hollows and protuberances, just like the surface of the earth itself which is varied….The next object that I observed was the essence or substance of the Milky Way. By the aid of a telescope, any one may behold this in a manner which so distinctly appeals to the senses that all the disputes which have tormented philosophers through so many ages are exploded by the irrefutable evidence of our eyes, and we are freed from wordy disputes upon the subject. For the galaxy is nothing else but a mass of innumerable stars planted together in clusters.

Galileo worked in Florence for the Medici family, and his work soon drew attention from theologians. He also worked in Padua, and tried to reconcile his work and the work of Copernicus with the teachings of the church. He was mulish and feisty, however, and insisted that the universe was mathematical to the core, and subject to the laws of mechanics which could be discovered. This brought him into conflict with religious authorities. In 1610, he wrote to Kepler "Here at Padua is the principal professor of theology, whim I have repeatedly and urgently requested to look at the moon and planets through my glass, which he obstinately refused to do. Why are you not here? What shouts of laughter we should have at this glorious folly!"

The pope condemned Galileo’s proposition that the earth rotated around the sun, in 1616 and warned him not to teach it. Galileo, feisty and stubborn to the end, published his Dialogue Concerning Two World Systems: Ptolemaic and Copernican, in which he presented a dialogue between those espousing the positions of the two. Ptolemy’s position was supported by a character whom Galileo named "Simplicio," an obvious taunt. The very name outraged church authorities who believed (correctly) that the character was intended as a caricature of the Pope..

In 1632, Galileo published his Dialogue on the two Chief Systems of the World in Italian, which lampooned the arguments of Ptolemy and Aristotle. Pope Urban VIII, who had been Galileo’s friend, had permitted him to write about different possible systems of the world on condition that he not presume to judge which actually existed. Urban was not pleased with Galileo’s remarks, and had him arrested by the Inquisition. The church’s major objection to his work was that he adopted an atomistic view of matter (it cannot be changed from one element to another), which directly contradicted Aristotle’s position and in the church’s eyes denied that transubstantiation (the conversion of the bread and wine of the Eucharist into the body and blood of Christ.) Urban also had political considerations. The Papacy had been weakened by the Protestant Reformation, and Urban did not feel the church could stand to be proven wrong. Galileo was accused of supporting the work of Copernicus rather than outright heresy; had he been charged with the latter, he could be sentenced to death. He was imprisoned and threatened with torture, under the influence of which he repudiated his earlier findings, "renouncing and cursing" his previous work as heresy, and was sentenced to house arrest for life. Even so, as guards escorted him to his home, he glanced up at the sky and proclaimed of the earth, "see, it’s still moving." Galileo continued to work from his house, and smuggled his works to Holland where they

were published. In 1638, when he went blind, the Pope refused to allow him to leave his house to consult a doctor in Florence. Even though blind, Galileo continued his work until his death five years later.

The Human Body: Aristotle, in addition to his other worthy endeavors, had dissected human bodies to determine how the body functioned. He concluded that the body had four "humors," blood, phlegm, yellow bile and black bile. He postulated that disease resulted from an imbalance in these humors. Aristotle’s work was enhanced by the work of Galen (129 - c.210 C.E.) who performed experiments on apes, whom he assumed had the same organs and body structure as humans. Galen concluded that two types of blood caused muscle movement and digestion; bright red blood which flood up and down through the arteries, and dark red blood which flowed through the veins.

With the advent of Scientific discovery, many scientists believed that the function of the body could be explained scientifically, and explained by universal laws. Andreas Vesalius: (1514 – 1564) was the first modern scientist to dissect human bodies and was the first to construct a human skeleton. (Although Aristotle had dissected human bodies, the church had forbidden this practice during the Middle Ages as sinful.) He published On the Fabric of the Human Body in 1543.

William Harvey (1578 – 1657) first explained circulation of the blood. Harvey adopted a scientific methodology, as had the astronomers of the era. He once remarked, "I profess to learn and teach anatomy not from books but from dissections; not from the tenets of philosophy but from the fabric of nature. Harvey worked before the invention of the microscope, and seldom used even a magnifying glass; however he did theorize that the heart was a pump which circulated blood through the body. Even he was not without some erroneous predisposition, however. He believed that the blood contained "vital spirits" necessary for survival. His work did, however, establish the basis for modern biology and medical study.

PART THREE: BACON AND DESCARTES – HOW DO WE THINK?

Sir Francis Bacon: Sir Francis (15461 – 1626) who called himself "a bell ringer who is first up to call others to church," was a lawyer, philosopher, and statesmen and helped separate Science from philosophy. He argued that medieval scholasticism had preoccupied itself with issues which had no practical consequences, often illustrated by the famous, "how many angels can dance on the head of a pin." Tradition, he argued, had no place in science, and he called for "a total reconstruction of science, arts, and all human knowledge."

Bacon’s work involved inductive reasoning: proceeding from observation and experimentation to conclusions or generalizations, that is from the specific to the general. (Aristotle had argued for deductive reasoning, proceeding from the general to the specific.) He argued that the truth of the universe could be revealed by scientific experiment, not by religion, and wrote, "Arts and sciences should be like mines; where the noise of new works and further advances is heard on every side." Scientists, he argued, should specialize, and work in cooperation to "overcome the necessities and miseries of humanity." Bacon is considered the father of the modern Scientific Method.

Sir Francis was famous in his own day, as he was Lord Chancellor for King James I of England which helped stir interest in science in that country, although it was limited to a small number of people. He only held the position for three years before he was fired for accepting a bribe. His actual scientific work was also of little value. He died after catching a cold during an experiment in which he stuffed snow into a dead chicken.

Rene Descartes:   used deductive reasoning, deducing a conclusion from a set of premises, to determine the nature of the Universe. This was contrary to other great thinkers of the time who used scientific observation. In 1637, he published his Discourse on Method, in which he discussed his rejection of the scientific teaching he encountered as a young man. He argued that too much of what had been taught had been based on tradition without critical commentary. He therefore "resolved no longer to seek any other science than the knowledge of myself or of the great book of the world."

Descartes stated that a person must begin with a blank slate, the famous tabula rasa, to understand the world through deductive reasoning. In his famous discourse, he at first questioned his own existence, but postulated that he did exist in his famous statement, Cognito Ergo Sum (I think, therefore I am.). To Descartes, the ability to think was the basis of human existence. Thereafter each problem had to be separated, "into as many parts as may be necessary for its adequate solution." That way, one could move from the simplest idea to the most complicated, similar to mathematical computation. The world could be reduced to two substances, "Mind," the "thinking substance;" and "matter," the "extended substance." Hence the famous expression of "mind over matter." (Growing old is often a problem of mind over matter: If you don’t mind, it doesn’t matter!)

Descartes defined matter as the infinite number of particles that fill all space. There was no void or vacuum. This, he said, could be discovered and described mathematically, as could the laws of motion. He argued that the existence of the material universe and even the existence of God could be deduced. "Begin with the smallest object, the easiest to understand, and gradually move to a knowledge of those that are the most complex.

Descartes’ theories left no room for medieval or ancient tradition. As a sign of the break of the old with the new, he published his work in French, rather than the traditional Latin, describing the latter as the language of ecclesiastical doctrine and scholasticism. His concept of God was similar to that of Kepler: God was a giant clockmaker who created the universe according to rules that the human mind could understand with proper reasoning. God then stepped back, and completely removed Himself from the workings of His creation. Descartes’ chief contribution is the theory that reason, not experimentation, is the proper method by which truth may be discovered.

PART FOUR: NEWTON PUTS IT ALL TOGETHER

Newton and Descartes both accepted Galileo’s revision of classical and medieval knowledge; but offered contrasting theories of Scientific Knowledge. Kepler, Galileo, and the other early scholars of the Scientific Revolution completely discredited Aristotelian theory, but did not synthesize their findings into a single comprehensive conclusion. That synthesis was completed by Sir Isaac Newton. (1642 – 1727)

Young Isaac was born into a gentleman family in England and attended Cambridge University where he demonstrated genius. He specialized in uniting experimental and theoretical elements of modern science. He was fascinated with alchemy, the belief that with the use of a catalyst known as the "philosopher’s stone" (like Harry Potter!), one element could be converted into another, the most famous illustration being the conversion of lead into gold. Although he has often been characterized as the perfect rationalist, he was in fact intensely religious.

Newton suffered from bipolar disorder, and frequently shut himself in his chambers for days on end, leaving only to deliver lectures at Cambridge where he was professor of mathematics. His meals were left at his door, and often left uneaten. In 1684, he began an intensive study of physics that lasted for eighteen months. In the opening lines of the third book of his Principia Mathematica (Mathematical Principals of Natural Philosophy), he wrote:

In the preceding books I have laid down the principles of philosophy (that is, science)….These principles are the laws of certain motions and powers or forces, which chiefly have respect in philosophy….It remains that from the same principles I now demonstrate the frame of the System of the World.

The Principia was the first synthesis of scientific principles. Newton combined Galileo’s experimental practice (empiricism) with Descartes’ logic and rigor, and thereby developed the theory of modern science: theory and experimentation combined into a single discipline.

A good graphic to illustrate deductive vs. inductive reasoning. Simply put, the scientific method!

The story of Newton observing a falling apple is in fact true. He was sitting under a tree on his family farm ruminating about celestial motion, when he saw the apple fall. He recognized that the force that causes objects to fall to the ground was the same force that kept the planets in motion. He theorized that Kepler’s law of planetary motion would be correct if the planets were being pulled toward the sun by a force whose strength was in inverse proportion to their distance from it.

On the basis of this theory, Newton developed a system of mathematical laws that explained motion and mechanics. The key feature of his work was the law of universal gravity: Every body in the universe attracts every other body in the universe in a precise mathematical relationship. His theory unified Kepler’s universe with Galileo’s rolling balls. He went beyond Kepler’s three laws of planetary motion and postulated a theory of universal gravitation, the existence of forces of attraction and repulsion between objects.

Newton also calculated, correctly, that the density of the earth is five and one half times that of water, and theorized (incorrectly) that electrical impulses activated the central nervous system. His theories were the forerunners of quantum physics and thermodynamics. He was the first to understand that all colors are composed of a mixture of the primary colors of the spectrum, and explained the phenomena of rainbows. He also calculated sound waves and invented calculus, a fact for which every advanced placement student will be eternally grateful. (Calculus was invented simultaneously by a German scholar, Gottfried Leibniz.) Newton also constructed the first reflecting telescope (previous telescopes had used refractive lens) and wrote a paper on optics in which he postulated that light could be mathematically described and analyzed. His work is often considered the beginning of theoretical physics.

Newton disagreed with Descartes as he believed that Descartes described the world as comprised totally of matter and thereby eliminated God from the equation. Newton, devoutly religious, believed that God did intervene from time to time to keep the great clock running, otherwise it would run down. This became known as deism. He wrote several manuscripts on religious doctrine in which he seemed to indicate that science and religion were not necessarily inconsistent with one another.

Although his predecessors never saw fame during their lifetimes, Newton became wealthy and a hero in his own lifetime. He was elected to Parliament in 1609 as the representative of Cambridge University, and became warden of the Royal Mint, and was knighted by the King. Even so, he was something of a weirdo. He was humorless and published his findings with reluctance, normally only when he feared that a rival might be him to the punch. He accused those working on similar problems of copying him, and was not generous in acknowledging that which he learned from others. He did, however, pay tribute to the work of Galileo by stating, "If I have seen further than others, it is because I have stood on the shoulders of giants." Alexander Pope, the English Poet, paid tribute to Newton’s discoveries in a famous verse:

Nature and Nature’s laws were hid in night. God said, Let Newton be! And there was light.

On his death, Newton was given a state funeral, and buried in Westminster Abbey.

The followers of Newton and Descartes often engaged in intense scientific debate as to the correctness of their respective positions. Gottfried Leibniz also agreed with Descartes and rejected Newton’s theory that God had to intervene from time to time to keep the machinery running. He concluded that the universe was, like God, infinite in space and time. The bodies of animals and humans ran like clocks that were set in motion, as was the universe. His thinking that God created the universe to run on its own without intervention constituted the hallmark of the "new philosophy."

CORNELL NOTES QUESTIONS…

1) How would you best explain how science was viewed in the Middle Ages?2) What were three causes of the Scientific Revolution?3) Explain the discoveries of Copernicus and Galileo and analyze how their beliefs differed

from the popular medieval thought and the Church beliefs.4) How were perceptions of the body and anatomy change from the medieval era to the

Scientific Revolution?5) Explain how Bacon and Descartes’ inductive and deductive reasoning were the foundations

of the scientific method.6) Explain Newton’s views on God’s role and place, if any, in the Universe.