THE SCIENTIFIC REVOLUTION
I. Legacy of the Middle Ages and the Renaissance
A. Monasteries and universities preserved the knowledge of the natural sciences collected in
Classical times
B. Medieval scholars studied Greek philosophy and the natural sciences
1. Further knowledge was gained from the Arabs and Asians by the Crusades and growing
trade
2. Discoveries of documents in Spain after the ousting of the Moors revealed much in both
Arab and Classical scholarship
3. Medieval scholars at universities tried to reconcile Classical philosophy and science with
Christian theology and philosophy
C. Medieval scholars thought that truth was human reason applied to divine revelation as
found in the Christian scriptures: “Scholasticism”
1. Observation of the natural world was used to support theories if it was consistent with
beliefs
2. Observed data was disregarded if it conflicted with accepted authorities
3. Observation of the natural world was not considered reliable
4. Aristotle, 4th century BCE , Greek, repeatedly by St. Thomas Aquinas, the leading
Scholastic philosopher
D. Renaissance scholars re-discovered much of the science from the Classical Age
1. Renaissance scholars translated many forgotten writings
2. Humanists frequently found that the ancients often had differing opinions
3. Renaissance scholars observed natural phenomena but they lacked a method of applying
their knowledge
4. Renaissance humanists refused to challenge knowledge of the Classical Age because of
their worship of that period
5. Age of Discovery increased the interest in the outside world and natural phenomena
a. There was a greater need for accurate knowledge for world travel
b. Europeans again gained knowledge from Asian science
6. Renaissance artists and humanists studying mathematics and anatomy suggested errors
in Ptolemy (the accepted expert in astronomy) and Galen (the accepted expert in
anatomy), both from 2nd century AD
7. Humanism encouraged the spirit of questioning and testing accepted knowledge
8. Universities in northern Italy (Padua, Bologna, Pisa) were the ground where many early
science discoveries were made
E. Ptolemy’s view of the universe was still accepted in the Renaissance
1. Ptolemaic theory placed the earth at the center of a finite universe (geocentric); Ptolemy
used the concept of epicycles to explain planetary retrograde motion
2. Geocentric theory was supported by the best Scholastic tradition
a. Geocentric theory reconciled perfectly with Christian theology
b. Human observation supported the geocentric theory
F. The Reformation brought a greater need by religious authorities to be errorless in all
matters: all questioning was seen as theological questioning and a challenge to religious
beliefs
II. Nicholas Copernicus (1473-1543)
A. Polish priest and scholar
1. Studied at University of Bologna where Ptolemy’s theory was being questioned because
of the complex explanation required
2. Assigned by the Church to research the heavens because religious saint and feast days
were no longer aligned
B. His 30 year study culminated with publication of Concerning the Revolutions of Heavenly
Bodies in 1543 (the same year of Copernicus' death)
1. Copernicus proposed that the earth and other planets revolved around the sun in
circular orbits at uniform speed
2. Heliocentric theory proposed that the earth rotated on its own axis
3. Copernican theory was simpler than the Ptolemaic but still could not be proven
mathematically
4. Strong reactions followed from many to Copernican (heliocentric) theory
5. Both Roman Catholic and Protestant theologians attacked the theory because of conflict
with established (geocentric theory) dogma
a. Giordano Bruno (1549-1600) supported Copernicus and was burned at the stake as a
heretic
b. Copernicus' treatise was placed on the Index of Prohibited Literature from 1616-1835
6. Majority of astronomers, mathematicians, and other scholars did not immediately accept
Copernicus' theory because of a lack of proof
III. Tycho Brahe (1546-1601)
A. Danish astronomer and court astrologer to the Holy Roman Emperor working in Prague,
Bohemia and a Danish island in the Baltic
B. Brahe designed and used measuring devices much better than those used by Copernicus
C. He built Europe's most modern astronomical laboratory
D. Brahe observed and collected data on positions of planets and stars keeping detailed charts
of more than 700 stars and the visible planets: the best observations until the use of the
telescope
E. Brahe questioned the Ptolemaic theory
1. It did not agree with his charts of the stars
2. He discovered a “new star”, a super-nova, in the constellation Cassiopeia: “New stars”
were contrary to Church dogma
3. Discovered Comet of 1577 coming in toward earth in an oval path
a. Comet was coming “through” the crystalline spheres without breaking them
b. Comet was in a non-circular orbit contrary to Church dogma
4. Refused to accept the Copernican theory as any better than Ptolemaic theory demanding
further proof; he sought a compromise between the two systems
F. He concluded that the planets revolved around sun but that the earth remained stationary
and everything revolved around the earth
G. Johannes Kepler, his assistant, and others would use the data collected by Brahe to support
Copernicus
IV. Galileo Galilei (1564-1642)
A. Galileo was a mathematician who discovered the law of the pendulum and the law of the
uniform acceleration of falling bodies
B. Galileo used the telescope (invented in 1608) in astronomical observation
1. Galileo’s observation confirmed the work of Copernicus and Kepler by observation
2. Galileo observed the craters of the Moon, sun spots, phases of Venus, and discovered four
moons of Jupiter
3. He published The Starry Messenger detailing his discoveries, 1610: the most
revolutionary
C. Galileo came into conflict with Inquisition (1614) in its fight against heresy (anything
contradicting the Bible) in the Counter-Reformation
1. The inquisition ordered Galileo to cease advocating heliocentric system (1616) and placed
The Starry Messenger and Copernicus’ Concerning the Revolutions of Heavenly Bodies
2. Published Dialogue Concerning the Two Chief Systems of the World (1632) supporting
Copernican theory further infuriating the Inquisition
3. Galileo was summoned before the Inquisition, forced to recant portions of his books
contrary to Scriptures and placed under house arrest for life
4. Dialogue placed on Index, 1633-1835, together with Kepler’s Epitome of Copernican
Astronomy
D. Galileo contributed to the study of dynamics (physics)
1. Galileo denied Aristotle's view that to keep a body in motion, a force must be
continuously applied
2. Galileo maintained that a body will continue in a given direction at uniform velocity
unless acted upon to change its direction or velocity
3. Galileo’s “principle of inertia” became the basis for Isaac Newton's First Law of Motion
4. Galileo offered a public demonstration of his experiments to prove his Law of Falling
Bodies
E. Galileo developed the scientific method
1. A hypothesis for the stated question would be by logical deduction or mathematics
2. Devise experiment to demonstrate and observe hypothesis
3. Accept or modify or reject hypothesis according to results of experiment
4. Effect: Experiment and observation replaced Scripture and Classical authorities as the
source of truth and knowledge
V. Johannes Kepler (1571-1630)
A. Assistant to Tycho Brahe; inherited his star charts
B. Kepler was a mathematician interested in proving Copernican theory deductively
C. Kepler found that circular orbits and speeds of Copernican theory did not conform to the
calculations of Brahe
D. Years of calculation combined astronomy with physics to adjust and prove the Copernican
theory
E. Kepler published three laws of planetary motion: two in 1609; the third in 1619
1. Kepler’s theory stated that the orbits of the planets are elliptical, not circular
2. Kepler’s theory stated that the planets move at different velocities in proportion to their
distance from the sun
3. Kepler’s theory stated that the speed of a planet moving on its orbit varied in a
mathematically predictable pattern explaining the relationship among sun and planets
F. Kepler published his conclusions in the Epitome of Copernican Astronomy (1616); placed on
Index of Prohibited Literature, 1633-1835
VI. Francis Bacon (1561-1626)
A. English lawyer and royal official
B. Wrote extensively on history, ethics, and philosophy
C. Published The Advancement of Learning, 1605, and Novum Organum, 1620
1. Promoted inductive method of modern science
a. Experimentation and observation
b. Collection and analysis of data
c. Generalizations can be made based analysis of data
2. Attacked unquestioning acceptance of previous authority
3. Empirical evidence can be used to produce benefits in all areas of knowledge besides
science
VII. René Descartes (1596-1650)
A. French mathematician who believed mathematics to be the tool to explain the universe
1. Invented analytic geometry to synthesize algebra and geometry
a. Using Descartes’ system, any geometric figure had an algebraic formula
b. He set the precedent for using the first letters of the alphabet for given quantities
and the last letters for unknown quantities
2. Believed that a philosophic system could be based on self-evident truths as geometric
theorems are derived from axioms
3. Basic problem to Descartes was to discover basic self-evident truths
a. Found that almost all could be doubted except thought which was required in order
to doubt
b. Only thought itself could not be doubted, therefore, "I think, therefore I am."
c. All accepted knowledge from earlier times called into doubt, and therefore, tested
4. Published Discourse on Method (1637) and continued to develop philosophic system
relying heavily on deductive reasoning
B. Greatest contribution was skepticism about previously accepted ideas and promotion of
deductive reasoning
VIII. Isaac Newton (1642-1727)
A. English mathematician building upon tradition of Copernicus, Kepler, and Galileo
B. Enormous contributions to development of science, the greatest since Aristotle
1. Invented "calculus of fluxions"
a. Newtonian calculus is basis of most modern mathematics
b. German, Leibnitz, invented calculus independently ten years later; most notations
used are Leibnitz'
2. Discovered composition of light and began scientific study of optics
3. Formulated first ideas on gravitation
a. Newton was first to produce mathematical explanation for planets' staying in orbit
b. Theory explained why planets stayed in orbit, why objects fall to earth, and the ebb
and flow of the tides
c. Theory: between any two bodies there exists an attraction directly proportional to
the product of their masses and inversely proportional to the square of the distance
between them
d. Published The Mathematical Principles of Natural Knowledge (Known as Principia,
published in Latin, 1687)
4. Formulated three laws of motion, basis of mechanics, published in Principia
5. Newtonian physics remained basis for concept of matter and the universe until
beginning of twentieth century and work of Einstein and others.
C. Served as Warden of the Mint, was two-term member of Parliament, taught mathematics at
Cambridge, and was President of the Royal Society of Science for 24 years
IX. Physiology and medicine: discoveries and developments
A. Questioning of Classical authorities Galen and Hippocrates began in 16th century
1. Eustachio and Falloppio (Italy) made advances and taught new anatomy (body tubes
bear their names)
2. Paracelsus (1493-1541) of Switzerland attacked unquestioning acceptance of Classical
knowledge
a. Argued that medicine is an experimental science
b. Emphasized link between medicine and chemistry
c. Insisted that anatomy be taught first hand through dissection
d. Driven from teaching due to controversy
B. Andreas Vesalius (1514-1564), Dutch professor of medicine at University of Padua, began
modern study of anatomy and physiology
1. Discovered errors of Galen; relied on observation
2. Published On the Structure of the Human Anatomy, 1543
3. Quit teaching due to severe criticism
C. William Harvey (1578-1650), English, educated in Padua
1. Discovered circulation of the blood, 1628
a. Relied on work of Servetus (Spain) who first described pulmonary circulation of blood
b. Published Anatomical Exercise on the Motion of the Heart and Blood in Animals
causing widespread opposition
2. Confirmed by Marcello Malpighi (1628-1694) who discovered capillary circulation to
explain flow from arteries to veins
a. Used microscope to study skin and nerve tissues
b. Studies of plant life founded study of plant anatomy important to botany
D. Robert Whytt (1714-1766) discovered reflex action and began study of neurology
E. Principle of inoculation for smallpox developed in Turkey
1. Zabdiel Boylston (1679-1766), American, first used
2. Edward Jenner developed first truly effective smallpox vaccine, 1798; first effective
vaccine to prevent disease
X. Chemistry: discoveries and developments
A. Study of chemistry retarded by medieval pseudo-science of alchemy
1. Alchemists sought gold, followed no scientific method, and disagreed about composition
of matter
2. Philosophers disagreed about composition of matter
a. Aristotelian view: all matter composed of air, earth, fire, and water or combination
b. Spagyrist view: all matter composed of salt, mercury, and sulfur or combination
B. Robert Boyle (1627-1691) of England
1. Attacked alchemists for failure to use careful observation of natural phenomena in The
Sceptical Chymist, 1661
2. Characterized an element as a pure substance which could not be broken down into
anything simpler
3. Maintained that Aristotelian elements failed this test
4. First to describe chemical compound: the result of the combination of two or more
constituents possessing qualities not present in any one constituent alone (definition still
accepted)
5. Predicted the discovery of many more elements
6. Boyle's Law: the volume of a given quantity of gas varies inversely with its pressure
C. Joseph Black (1728-1799), Scottish physician and chemist, proved that air is not a single
element but consists of several gasses
D. Sir Henry Cavendish (England) discovered hydrogen ("flammable air"), 1766
E. Joseph Priestley (England) and Carl Scheele (Sweden) each independently discovered
oxygen, 1774
F. Anton Lavoisier (1743-1794) (France) described theory of combustion
1. Called the "Father of Modern Chemistry"
2. Demonstrated the increase in weight in burning a substance is the chemical addition of
oxygen
3. Demonstrated that the total weight of all chemical compounds involved in combustion is
the same at the end of the reaction as at the beginning: Law of the Conservation of
Matter
4. Elementary Treatise on Chemistry (1789) listed 33 elements (23 are still recognized)
5. Standardized the weights and measures of France
6. Executed in Reign of Terror during the French Revolution
XI. Physics: discoveries and developments
A. William Gilbert (1540-1603) of England
1. Re-awakened interest in magnetism
2. Demonstrated that the earth had magnetic properties and that iron could be magnetized
3. Demonstrated static electricity rubbing amber on fur to attract straw or hair (elektron is
Greek for amber)
B. Developed slowly and steadily after contributions of Galileo and Newton
C. Advancements in study of electricity
1. Leyden jar to provide electrical charge for experiments, 1745
2. Benjamin Franklin (American) demonstrated that lightning is electricity and invented
lightening rod, 1752
3. Alessandro Volta (Italy) invented battery, 1799, making possible a steady flow of
electricity for experiments or practical application
4. Formed basis for science and technology of 19th century
XII. Biology: discoveries and developments
A. Carolus Linnaeus (1707-1778), Swedish botanist developed system for classification of plants
and animals by genus and species
1. Published Systema Naturae, 1735
2. Believed that species are constant
3. Developed botanical garden
4. 1600 botanical gardens in Europe by 1800
B. Count of Buffon (1707-1788), French zoologist made important discovering in classification of
animal life
1. Published 44-volume series on natural history, 1749-1804
2. Europeans organized zoos to exhibit non-European animals
XIII. Geology: discoveries and developments
A. William Gilbert (1540-1603) of England, in De magnete (1600) suggested that earth operated
like a huge magnet
B. James Hutton (1726-1797) Scotsman
1. Published The Theory of the Earth, 1795
2. Concluded that surface of the earth had been undergoing gradual changes for many
thousand years
XIV. Development of Scientific Tools and Academies
A. Many important tools devised for exact observation and calculations (now required for
accurate experiments)
1. John Napier (Scotland) invented logarithms (demonstrated, 1614)
a. First slide rule invented by William Oughtred and Edmund Wingate, 1630
b. Used for large, complicated mathematical calculations
2. Mathematical notation standardized
3. First practical telescope, 1608, Johann Lippershey (Netherlands); improved by Galileo
for astronomical use
4. Zacharias Jansen (Netherlands) invented microscope, 1590; Anton van Leeuwenhoek
discovered bacteria using it
5. Christian Huygens (Netherlands developed pendulum clock, 1656
6. Blaise Pascal (France) developed mercury barometer, 1648
7. Accurate thermometers with standard measurement
a. Daniel Fahrenheit (German) developed temperature scale, 1721
b. Anders Celsius (Sweden) developed temperature scale, 1742
B. Scientific academies grew from need for place to discuss and exchange information and
research
1. Universities hesitant because many were controlled or endowed by churches
2. Small academies established in Italy at end of 17th century
a. Galileo belonged to the Roman Society in 1603
b. Medici family founded Academy of Experiments in Florence in 1657
3. French Academy of Sciences began meeting informally, 1631; formally recognized by
government in 1666 by Louis XIV
4. Royal Society of England began meeting in 1645; formally chartered by Charles II, 1662,
as "The Royal Society of London for Promoting Natural Knowledge"
5. Academies published journals and sponsored meetings to exchange ideas
6. Academies raised money for research and sought ways to apply knowledge to practical
problems
XV. Steady application of science and technology followed
A. Agricultural Revolution of the 18th century came as a result of the application of scientific
methods to farming
B. Industrial Revolution of 19th Century rests upon developments of Scientific Revolution
C. Modern thinking involves using the scientific method in almost every field of data
1. Doubt of accepted belief
2. Formation of a question
3. Gathering of all known data available through research
4. Formation of a hypothesis to answer the question
5. Development of an experiment to test the hypothesis
6. Results of the experiment are observed and recorded
7. If the hypothesis is supported, the experiment is repeated. If the hypothesis is not
supported, it is adjusted and the process begins again.
D. Modern conflict between science and religion begins with Copernicus