The Scientific Revolution

What Was the Scientific Revolution?

A revolution in human understanding and knowledge about the physical universe17th centuryBegan with Kepler, GalileoEnded with Newton

The BIG PICTURE:The scientific revolution is historically important for three reasons: it laid the basis for our modern view of

the world as a rational, ordered place it shifted the nature of discourse in

"natural philosophy" from reason (deductive) to empirical (inductive) method

Finally, it affected the thinking of a wide range of people from poets and philosophers to practical men of politics and economics

“Science” Before the Scientific RevolutionBased almost entirely on reasoningExperimental method or observation wasn’t used at allScience in medieval times

• Alchemy• Astrology• tradition

A medieval alchemist

Factors Leading to the Scientific Revolution

Rise of universitiesContact with non-Western societiesThe RenaissanceExploration

RationalismReason, not tradition, is the source of all knowledgeRené Descartes (1596–1650)French philosopher and mathematicianCogito ergo sum (“I think, therefore, I am”)Deductive reasoning

René Descartes

Empiricism

The belief that experience is the only true source of knowledgeRoger BaconShift toward empiricism a hallmark of the Scientific RevolutionHelped lead to the development of the scientific method Roger Bacon

Francis Bacon andthe Scientific Method

1561–1626English philosopher and empiricistInductive reasoningArgued for experimental methodology

The Scientific Method

Science as a multiple-step process:

3. Test the theory with experiments

2. Develop a theory that explains the object or phenomenon

1. Observe an object or phenomenon

Roots of Scientific Thought: Aristotle

4th century BCE Greek philosopher and scientistWrote several scientific worksHis work laid the foundation for scientific study through the medieval eraGravity/Theory of falling objectsAstronomy: Crystal spheres

Roots of Scientific Thought: Ptolemy

2nd century CE Greek astronomer, mathematician, and geographerThe Almagest (Syntaxis)Geocentric (earth-centered) model of the universeMotion 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 mathematicianCommentariolus (1514)Concerning the Revolutions of the Celestial Spheres (1543)

Tycho Brahe (1546–1601)Danish astronomerAmassed accurate astronomical dataTheorized a system distinct from both the Ptolemaic and Copernican onesArgued that the Moon and Sun revolve around the Earth while other planets revolve around the SunBEST. DEATH. EVER.

Johannes Kepler (1571–1630)

German astronomer and mathematicianStudent of TychoDidn’t agree with Tycho’s interpretation of dataDisagreed with Copernicus, claiming that other bodies moved in elliptical motion, as opposed to circular motionsTheorized three laws of planetary motion using Tycho’s data

Kepler’s Three Laws of Planetary Motion

Law of Ellipses: Planets orbit the sun in elliptical patternsLaw of Equal Areas: The speed of planetary motion changes constantly depending on the distance from the SunLaw of Harmonies: Compares the movement of all the planets, claiming a similarity in their motion

Galileo Galilei (1564–1642)

Italian mathematician, astronomer “Father of Science”Telescopes and astronomical discoveriesTheory of falling objects; disproved Aristotle

Galileo’s telescopic drawing of the moon

Dialogue on the Two Chief Systems of the WorldGalileo’s major workWritten in 1632Argued in favor of the heliocentric model of the universe

Frontspiece from the Dialogue; from left to right, the figures shown are Aristotle, Ptolemy, and Copernicus

Galileo vs. the Catholic Church

The church condemned heliocentric conceptions of the universeThe Roman InquisitionGalileo’s trialGalileo recants, put under house arrest

19th-century depiction of Galileo before the Inquisition tribunal

Sir Isaac Newton (1642–1727)English astronomer, physicist, and mathematicianSynthesized the works of Copernicus, Kepler and GalileoThe Principia

Newton’s Laws of Motion

First Law: Law of InertiaSecond Law: Fundamental Law of DynamicsThird Law: Law of Reciprocal Actions

Medicine Before the Scientific Revolution

Based on traditionThe Church

Illustration depicting a

bloodletting, an accepted

medical procedure before the Scientific

Revolution

Ancient Medicine: Galen (131–201 CE)

Greek physicianOn the Elements According to Hippocrates“Bodily humours”Two types of bloodOn the Use of the Parts of the Body

Medieval Medicine: The Catholic Church

Provided for care of the poor and the sickMinor clerics took on physician-like rolesEventually, university-trained physicians displaced clerical physiciansClerics treat a royal patient with leeches

Andreas Vesalius (1514–1564)

Belgian anatomistOn the Fabric of the Human Body Corrected many of Galen’s errors

William Harvey (1578–1657)

English physicianOn the Movement of the Heart and Blood in AnimalsDescribed the functioning of the heart and circulatory systemDisproved Galen’s theories

Chemistry

Robert Boyle (1627–1691)Antoine Lavoisier

(1743–1794)

Joseph Priestley (1733–1804)

Carolus Linnaeus (1707–1778)

Swedish botanistClassification and naming of flora and fauna

Jean-Baptiste Lamarck(1744–1829)

French biologistEarly theory of evolutionPhilosophie ZoologiqueLamarck’s “laws”

Mathematics

Math symbols for addition, subtraction, multiplication and divisionAnalytical geometry: DescartesCalculus: Newton

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New Invention: The Telescope

Invented in the NetherlandsGalileoNewton

Illustration of Galileo at his

telescope

New Invention: The Microscope

Hans JanssenAnton Van LeeuwenhoekRobert Hooke

A Janssen microscope, c.1600Hooke’s drawing of a flea (from Micrographia)

New Invention: The Pendulum Clock

Invented by Christiaan Huygens, a 17th-century Dutch scientistAllowed scientists to more accurately measure time

Huygens’s design for a pendulum clock

New Invention: Barometer

Invented by 17th-century Italian physicist Evangelista TorricelliThe barometer measures air pressure

Torricelli’s barometer experiment

New Invention: Thermometer

Invented in the 17th century by Santorio Santorio, an Italian scientistFerdinand IIGabriel FahrenheitAnders Celsius

Illustration depicting Santorio’s thermometer

Santorio Santorio

New Invention: Mechanical Calculator

Invented by Wilhelm Schickard, a 17th-century German inventorGottfried von Leibniz’s “Step Reckoner”

Wilhelm SchickardA 1624 sketch Schickard made

of his calculator

The Significance of the Scientific Revolution

Abandonment of ancient and medieval systemsDevelopment of the scientific methodThe Enlightenment