1. The Scientific Revolution
The Scientific Revolution marked the beginning of a dramatic shift in how people viewed the world. The medieval and early modern European outlook had been dominated by religion. As a result of this revolution, many came to see the world predominantly in secular and scientific ways. In the short term, the Scientific Revolution set the stage for the Enlightenment; its long-term repercussions can still be felt today.
From “Why?”
To “How?”

3. What Was the Scientific Revolution?
A revolution in human understanding and knowledge about the physical universe
Epistemological Shift
The Scientific Revolution is generally viewed as a 17th-century phenomenon. Most historians consider it to have started with the astronomical discoveries of individuals like Kepler and Galileo and ended with the publication of Newton’s major works. We will describe these “bookends” of the Scientific Revolution in greater detail later in this discussion.

4. Factors Leading to the Scientific Revolution
Rise of universities
Contact with non-Western societies
The Renaissance
Exploration
A number of factors helped lay the groundwork for the Scientific Revolution:
The first universities appeared during the Middle Ages. Although universities initially focused primarily on topics like law and philosophy, they gradually expanded their offerings and came to establish professorships in areas such as mathematics, astronomy, medicine, and other science-related disciplines. Universities brought together leading scientific minds, encouraged intellectual debate, and sparked interest in research and discovery.
Muslim scholars of the Middle Ages made several important mathematical and scientific discoveries. During the 12th and 13th centuries, both the Crusades and the expansion of trade networks brought Europeans into greater contact with Muslim societies. Both cultural and intellectual exchanges occurred; this infusion of new ideas helped improve Europeans’ understanding of mathematical principles in particular and of science in general.
As the Renaissance dawned and inspired advances in art and literature, educated Europeans began to look beyond the church and the Bible for knowledge and truth. In addition to serving as patrons of the arts, wealthy families such as the Medicis in Italy also supported scientific research.
The Age of Exploration also provided impetus for the Scientific Revolution. The challenges of navigating across the Atlantic Ocean and around Africa motivated advances in mathematics, astronomy, and cartography (mapping). European monarchs interested in expanding their overseas empires (including King John of Portugal, King Ferdinand and Queen Isabella of Spain, and Queen Elizabeth I and King Charles II of England) provided funding and/or support for scientific research.

5. 1600s-A cruel era. Sickness, poverty and
Suffering were viewed as rebukes from God.
Traitors Heads
Mounted On pikes

6. Two disasters
Fire and Plague

7. Rationalism René Descartes (1596–1650)
French philosopher Cogito ergo sum (“I think, therefore, I am”)
Deductive reasoning
The philosophy of rationalism holds that all knowledge comes from reason. René Descartes was one of the most important philosophers and mathematicians of his time; many regard him as the father of modern rationalism. In Discourse on Method and The Meditations, he reasoned that all of his prior knowledge was subject to doubt because it was based on traditional beliefs rather than on reason. He pondered what he could honestly say he knew to be true, going so far as to doubt whether he was awake or dreaming—or if he even existed. He then began to reconstruct his world view: he knew that his thoughts existed, which then suggested the existence of a thinking being—himself. Descartes then came to his famous conclusion, “Cogito ergo sum,” which means “I think, therefore, I am.”
Descartes’ conclusions were based on deductive reasoning, which involves using a general principle to draw conclusions about a specific instance. For example, once he had come up with Cogito ergo sum, he used it to draw a further conclusion: because the mind “cannot be doubted but the body and material world can, the two must be radically different.” In other words, Descartes drew a clear distinction between mind and matter—an idea that helped break down superstitions that had influenced science in the medieval era.
René Descartes

8. Francis Bacon and the Scientific Method
1561–1626
English philosopher Inductive reasoning
Argued for experimental methodology
English philosopher Sir Francis Bacon laid the theoretical groundwork for what became known as the scientific method. His ideas about science incorporated what is known as inductive reasoning, which involves using concrete facts to extrapolate broader conclusions. (Inductive reasoning is the opposite of deductive reasoning.) Bacon argued that scientists should work from the specific (observable data) to the general (rules and theories based on that data). He believed that all scientific research should rely on careful observation and experimentation rather than simply relying on one’s own thought and reasoning, as earlier scientific thinkers had. The data obtained should then be recorded and analyzed according to logic and reason, then used to produce a testable hypothesis.

9. Models of the Universe: Geocentric vs. Heliocentric
Geocentric: the Earth is at the center of the universe; all heavenly bodies move around the Earth
Heliocentric: the Sun is at the center of the universe; all heavenly bodies move around the Sun—including the Earth
Derived from the Greek words “geo” (meaning earth) and “centron” (meaning center), the geocentric view were generally the view pushed by Aristotle and Ptolemy (see above). Geocentricism was officially endorsed by the Catholic Church and taught at religious schools and universities.
Derived from the Greek works “helios” (meaning sun) and “centron” (meaning center), the heliocentric conception was the most prominent theory pushed during the Scientific Revolution.

10. Nicholas Copernicus (1473–1543)
Polish astronomer and mathematician
Concerning the Revolutions of the Celestial Spheres (1543)
In 1514, Copernicus wrote Commentariolus, a short, handwritten notebook of observations in which he laid out the foundations of his heliocentric theories. He did not sign his name to Commentariolus and distributed it only to a few friends, fearing that the controversial nature of his thoughts might provoke the anger of the Catholic Church. The following year, however, he began to write Concerning the Revolutions of the Celestial Spheres, in which he expanded on the heliocentric model he had proposed in Commentariolus. He worked on the book for the rest of his life; it was finally published just before his death in Despite the importance of Copernicus’ work, at the time his theories did little more than spark debate among scientific thinkers and had little initial impact outside of academic circles. His ideas would provide the foundation for the revolutionary work of later scientists.

11. Johannes Kepler (1571–1630) German astronomer and mathematician
Theorized three laws of planetary motion using Tycho’s data
Kepler originally studied theology but ended up as a professor of mathematics. As a student of Tycho, he studied both his teacher’s works as well as the writings of Copernicus. Kepler claimed that while Tycho’s data was correct, his interpretations of the data were incorrect; he further argued that Tycho’s data actually proved Copernicus correct.
Kepler also took issue with Copernicus’ claim that astronomical bodies moved in circles, asserting instead that they moved in elliptical patterns—an assertion that later proved correct. Kepler used Tycho’s data and his own observations to develop three laws of planetary motion and proved the core of heliocentric theory.

12. Kepler’s Three Laws of Planetary Motion
Law of Ellipses: Planets orbit the sun in elliptical patterns
Law of Equal Areas: The speed of planetary motion changes constantly depending on the distance from the Sun
Law of Harmonies: Compares the movement of all the planets, claiming a similarity in their motion
Kepler’s data led him to propose three theories concerning planetary motion:
The Law of Ellipses: Asserts that planets orbit the sun elliptically (i.e., in oval patterns). This law explained why theories that claimed that planets orbited the Sun or Earth in circular patterns were inconsistent with observed data.
The Law of Equal Areas: Claims that the speed of planetary motion changes constantly depending on the planet’s distance from the Sun. Planets move faster when closer to the Sun, slower when further away.
Law of Harmonies: Compares the movement of all the planets using ratios, claiming a similarity in the motions of all the planets in the galaxy.

13. Galileo Galilei (1564–1642) Italian mathematician, astronomer
“Father of Science”
Telescopes and astronomical discoveries
Theory of falling objects; disproved Aristotle
Galileo is considered the father of modern physics, astronomy, and more generally the “Father of Science.” He created several different telescopes (improving the power of with each successive model) and used them to record extraordinary amounts of data. His interpretations of the data yielded some remarkable discoveries, including:
Stars were farther away than planets
There were mountains on the Moon
Jupiter has four moons
Saturn has rings
He eventually compiled and published his observations in a 1610 work titled The Starry Messenger. Galileo’s work, combined with the previous discoveries of Copernicus and Kepler, left little doubt among the mainstream scientific community that the Ptolemaic model of the universe was incorrect.
He also conducted a famous experiment in which he showed Aristotle had been mistaken in his assumption that objects of different weights falling at different rates of speed. Having proven this, he went on to establish an explanation of speed and motion. Galileo also created a thermometer, which permitted more accurate data collection.
Galileo’s telescopic drawing of the moon

14. Galileo vs. the Catholic Church
The church condemned heliocentric conceptions of the universe
The Roman Inquisition
Galileo’s trial
Galileo recants, put under house arrest
Galileo’s scientific observations proving that the Earth wasn’t at the center of the universe had vast religious implications. The Catholic Church perceived heliocentric theories as questioning long-held doctrinal teachings about the nature of the heavens. The Church ultimately found it easier to condemn the heliocentric view of the universe as “foolish” and “formally heretical” rather than figure out how it could fit into a religious framework.
In 1630, Galileo had received conditional permission from the Vatican to publish the Dialogue. Months after its first printing in 1632, however, Pope Urban VIII ordered a halt to distribution of the book and created a special commission to investigate whether the work was heretical. The commission recommended that Galileo’s case be referred to the Roman Inquisition, which ruled on cases of suspected heresy. Galileo’s trial before the Inquisition tribunal began in April 1633.
Galileo defended himself by arguing that while the Church had earlier told him not to hold or believe Copernican theories, it had never told him not to teach about them. The tribunal threatened Galileo with torture, imprisonment, and even burning at the stake if he refused to recant his views; eventually, he succumbed. Sentenced to house arrest due to his fragile health and advanced age, Galileo was forced to recite prayers every day and wasn’t supposed to be allowed visitors, though neither of these were well enforced. In spite of the toll it had taken on him both mentally and physically, Galileo’s battle with the Church didn’t dampen his intellectual curiosity, and he continued to write, research, and publish. The trial had a chilling effect on scientists practicing in Italy and pushed the focus of mainstream science north to places like England and France. It also highlighted the tensions between religion and science.
19th-century depiction of Galileo before the Inquisition tribunal

15. Sir Isaac Newton (1642–1727)
English astronomer, physicist, and mathematician
Synthesized the works of Copernicus, Kepler and Galileo
The Principia
Considered by many to be the greatest figure of the Scientific Revolution, Newton synthesized the works of Copernicus, Kepler, and Galileo in formulating his theories on gravity and motion. After decades of research, he presented the foundation of these theories (along with other observations concerning mathematics and geometry) in the Principia, perhaps the most influential science book ever written. The Principia presented a new view of the world, one expressed in entirely mechanical terms, with Newton portraying the universe as a large clock that operated by a consistent set of rules. The book was well received by the academic community of Europe at the time and his new world view became the accepted paradigm until the atomic age.
Legend holds that Newton “discovered” gravity when an apple fell on his head from a nearby tree, although many believed Newton—who loved to tell stories—made the whole thing up.

16. Newton’s Laws of Motion
Law of Inertia: Argues that bodies in motion tend to stay in motion unless acted on by an outside force. This force can be something viable and obvious or something more subtle like gravity.
Fundamental Law of Dynamics: Explains how the velocities of objects change when outside forces are applied. Considered the most important of the three laws of motion.
Law of Reciprocal Actions: Posits that for for every action, there is an equal and opposite reaction.
The central unifying element for Newton was that motion in the heavens was linked to motion on earth by the law of universal gravity.
First Law: Law of Inertia
Second Law: Fundamental Law of Dynamics
Third Law: Law of Reciprocal Actions

17. William Harvey (1578–1657) English physician
Described the functioning of the heart and circulatory system
In 1628, English physician William Harvey wrote On the Movement of the Heart and Blood in Animals, a work based on years of observation and dissection of both animal and human subjects. In the book, Harvey argued that blood was pumped through the body by the heart and constantly circulated; he also proved that the same blood flows in both veins and arteries. Harvey’s conclusions disproved Galen’s theories and created a basic model of blood circulation that is still recognized as the standard today.

18. Chemistry Joseph Priestley (1733–1804) Antoine Lavoisier (1743–1794)
Chemistry as we know it today didn’t really exist until the Scientific Revolution. Modern chemistry began with Robert Boyle, a British scientist who was the first to make a distinction between a chemical element and a chemical compound. He is most famous for Boyle’s Law, which states that the volume of a gas under compression is inversely proportional to the amount of pressure.
Another British chemist, Joseph Priestley, was the first to isolate and identify oxygen. He also discovered other gases (including ammonia and carbon monoxide), wrote a book on electricity, and coined the term “rubber.”
French scientist Antoine Lavoisier conducted several experiments involving combustion. He discovered not only that substances combine with oxygen when they burn, but also showed that water was made up of hydrogen and oxygen. In addition, he identified 23 other elements and invented a nomenclature (naming system) for chemical elements.
Antoine Lavoisier (1743–1794)
Robert Boyle (1627–1691)

19. Mathematics
Math symbols for addition, subtraction, multiplication and division
Analytical geometry: Descartes
Calculus: Newton  +
The modern signs for mathematical operations were created by Francois Vieta in France in 1603 and were adopted as standard during the Scientific Revolution. In addition, new branches of mathematics arose: René Descartes came up with analytical geometry and Sir Isaac Newton invented calculus, the study of rates of change. - 

20. New Invention: The Telescope
Invented in the Netherlands
Galileo
Newton
The telescope was invented in the Netherlands in the late 16th century. Until Galileo made improvements to it in the early 1600s, it had not really been widely used as a practical tool for scientific observation. Sir Isaac Newton made further refinements in the early 1700s when he invented the reflector telescope, which uses a curved mirror to magnify objects to a much greater degree than a simple glass lens is capable.
Illustration of Galileo at his telescope

21. New Invention: The Microscope
Hans Janssen
Anton Van Leeuwenhoek
Robert Hooke
Considerable scholarship exists tracing the origin of the microscope. The first simple microscopes appeared during the Renaissance, but were limited both in power and in the range of tasks for which they could be used. Around 1590, Dutch spectacle makers Hans Janssen and his son Zacharias began to construct compound microscopes, which used several lenses and produced much greater magnification of objects. In the mid-1600s, another Dutchman named Anton Van Leeuwenhoek developed new methods for grinding and polishing tiny lenses of great curvature which gave magnifications up to 270 diameters, the finest known at that time. He used these lenses to build vastly improved microscopes and make several groundbreaking observations: he was the first to see bacteria, blood corpuscles, and the “life” found in a drop of water. In the 1660s, Robert Hooke of the Royal Society of London improved on Leeuwenhoek’s microscope and performed a series of weekly demonstrations to show the power of the instrument. In 1665, he wrote Micrographia, a finely illustrated compendium of microscopic observations that also used the word “cell” as a biological term for the first time; the book sparked increased public interest in microscopy.
Hooke’s drawing of a flea (from Micrographia)
A Janssen microscope, c.1600

22. The Significance of the Scientific Revolution
Abandonment of ancient and medieval systems
Development of the scientific method
The Enlightenment
The most obvious result of the Scientific Revolution was the rejection of ancient and medieval systems in science, astronomy, and medicine. After the Scientific Revolution, many previously accepted theories had been completely disproved or discarded.
The methods developed during the Scientific Revolution would fuel discoveries for centuries to come. Basing science more firmly in empiricism made conclusions more consistent, reproducible, and accurate.
The Scientific Revolution also set the stage for the Enlightenment. Like the pioneers of the Scientific Revolution, Enlightenment thinkers strove to make conclusions based on observation, logic, and reason, rather than on faith.
Though the Scientific Revolution had little immediate impact on society as a whole, its long-term repercussions can still be felt today. Perhaps more important than the specific advances in science, the Revolution represented a shift in worldview: it was an intellectual revolution that changed the way that people saw and interpreted the world around them.