The Scientific Revolution

What Was the Scientific Revolution?

• A revolution in human understanding and knowledge about the physical universe

• 17th century• Began with Kepler, Galileo• Ended with Newton

“Science” Before the Scientific Revolution

• Based almost entirely on reasoning

• Experimental method or observation wasn’t used at all

• Science in medieval times• Alchemy• Astrology

A medieval alchemist

Factors Leading to the Scientific Revolution

• Rise of universities

• Contact with non-Western societies

• The Renaissance

• Exploration

Rationalism• Reason, not tradition, is the

source of all knowledge• René Descartes (1596–1650)• French philosopher and

mathematician• Cogito ergo sum (“I think,

therefore, I am”)• Deductive reasoning

René Descartes

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.”

Empiricism• The belief that experience is

the only true source of knowledge

• Roger Bacon• Shift toward empiricism a

hallmark of the Scientific Revolution

• Helped lead to the development of the scientific method

Roger Bacon

Francis Bacon andthe Scientific Method

• 1561–1626• English philosopher and

empiricist• 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.

The Scientific Method

Science as a multiple-step process:

5. Analyze results of the experiment to form a conclusion that either proves or disproves the hypothesis

3. Perform experiments to test the hypothesis

4. Record results of experiments

1. Scientists identify a problem

2. Form a hypothesis that can be tested

Roots of Scientific Thought: Aristotle

• 4th century BCE Greek philosopher and scientist

• Wrote several scientific works• His work laid the foundation for

scientific study through the medieval era

• Gravity/Theory of falling objects• Astronomy: Crystal spheres

Roots of Scientific Thought: Ptolemy

• 2nd century CE Greek astronomer, mathematician, and geographer

• The Almagest (Syntaxis)• Geocentric (earth-centered)

model of the universe• Motion of the planets

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

Nicholas Copernicus (1473–1543)• Polish astronomer and

mathematician• Commentariolus (1514)• Concerning the Revolutions

of the Celestial Spheres (1543)

Tycho Brahe (1546–1601)• Danish astronomer• Amassed accurate

astronomical data• Theorized a system

distinct from both the Ptolemaic and Copernican ones

• Argued that the Moon and Sun revolve around the Earth while other planets revolve around the Sun

Johannes Kepler (1571–1630)• German astronomer and

mathematician• Student of Tycho• Didn’t agree with Tycho’s

interpretation of data• Disagreed with Copernicus,

claiming that other bodies moved in elliptical motion, as opposed to circular motions

• Theorized three laws of planetary motion using Tycho’s data

Galileo Galilei (1564–1642)• Italian mathematician, astronomer • “Father of Science”• Telescopes and astronomical

discoveries• Theory of falling objects; disproved

Aristotle

Galileo’s telescopic drawing of the moon

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

19th-century depiction of Galileo before the Inquisition tribunal

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.

The Significance of the Scientific Revolution

• Abandonment of ancient and medieval systems• Development of the scientific method• The Enlightenment

Critical Thinking Questions to Answer

• Explain the reasons as to why the Scientific Revolution occurred.

• Give two (2) examples as to how the Scientific Revolution effects your every day life today. Explain.