Chapter 22: Enlightenment and Revolution, 1550 - 1789
Section 1 – The Scientific Revolution
The Roots of Modern Science
Before 1500, scholars decided what was true or false by referring to an _______________________________________
author or to the ____________. Few scholars challenged the scientific ideas of ancient thinkers or the church
by observing nature for themselves.
 The Medieval View
o During the Middle Ages, scholars believed that the earth was an immovable object located at
______________________________________

The sun, the moon and all other planets moved in circular paths around earth

____________________ supported this view: the sun appeared to be moving around the earth
o This earth-centered view of the universe was called the ___________________________

The idea came from _________________

______________________ taught that God had deliberately put the earth at the center of the
universe
 A New Way of Thinking
o Beginning in the mid-1500s, a few scholars published works that challenged the ideas of the
ancient thinkers and the church
o They replaced old assumptions with new theories, launching the __________________________________

Was based upon careful observation and a willingness to question accepted beliefs
o A combination of discoveries and circumstances led to the Scientific Revolution

During the ____________________, European explorers traveled Africa, Asia and the Americas

The discoveries made there opened Europeans to the possibility that there were
new truths to be found

__________________________ also fueled a great deal of scientific research, especially in
math and astronomy

The ______________________________ helped spread challenging ideas
o As scientists looked closely at the world around them, they made observations that didn’t
match up with ancient beliefs
A Revolutionary Model of the Universe
An early challenge to accepted scientific thinking came when a group of scholars began to question the
geocentric theory
Chapter 22: Enlightenment and Revolution, 1550 - 1789
 Heliocentric Theory
o The geocentric theory did not accurately explain the movements of the sun, moon and planets
o This troubled Nicolaus Copernicus

Became interested in an old ___________ idea that the __________ stood at the center of the
universe

After studying planetary movements for 25 years, he reasoned that the earth and other
planets _______________________________

His _______________________________, or sun-centered, theory did not explain why the planets
orbited the way they did

Also knew that most scholars and clergy would ____________ his theory because it
contradicted their religious views

Fearing ridicule and persecution, he did not publish his findings until
_________________________________________in 1543
o Over the next century and a half, scientists built on the foundation he laid

In 1601, Johannes Kepler concluded that certain mathematical laws govern planetary
motion

1 of these laws showed that planets revolve around the sun in _____________________
________________

Kepler’s laws showed that Copernicus was right by demonstrating ________________________
that the earth revolved around the sun
 Galileo’s Discoveries
o An Italian scientist named Galileo Galilei had learned that a Dutch lens maker had built an
instrument that could enlarge far-off objects

Build his own telescope and used it to study the heavens in 1609
o In 1610, he published a book called ____________________________, which described his observations

Announced that Jupiter had 4 moons and that the sun had dark spots

Noted the earth’s moon had a rough, uneven surface

Shattered __________________________ theory that the moon and stars were made of a
pure, perfect substance
o Galileo’s observations along with his laws of motion, _________________ the theories of Copernicus
 Conflict with the Church
o Galileo’s findings frightened _______________________________ leaders
Chapter 22: Enlightenment and Revolution, 1550 - 1789

If people believed the church was wrong about this, they could question other church
teachings
o In 1616, the Catholic Church warned Galileo not to defend Copernicus’s ideas

He remained publicly silent but __________________________________
o In 1632, he published another book where he once again supported the ideas of Copernicus

The pope summoned him to Rome to stand trial before the _____________________

Stood before the court and under the threat of torture, read aloud a signed
confession agreeing that Copernicus’ ideas were false
o Was never free again, living under _______________________ until his death in 1642

His books and ideas still spread all over Europe

In ____________, the Catholic Church officially acknowledged that Galileo had been right
The Scientific Method
The revolution in scientific thinking that Copernicus, Kepler and Galileo began developed into a new
approach called the ___________________________, a logical procedure for gathering and testing ideas.
 Bacon and Descartes
o The work of 2 important thinkers in the 1600s helped to advance the scientific method

_____________________

Believed by better understanding the world, scientists would generate practical
knowledge that would improve people’s lives

He urged scientists to experiment and then draw conclusions
o Called ____________________, or the ___________________________________

_______________________

Rather than relying in experimentation, he relied on _______________________________

Believed everything should be doubted until proven by reason
o The only thing he knew for certain was that he existed because, as he
famously wrote, “I think, therefore I am”
o Modern scientific methods are based on the ideas of Bacon and Descartes
The Scientific Revolution Spreads
 Scientific Instruments
o The first __________________ was invented by a maker of eyeglasses, Zacharias Janssen, in 1590
Chapter 22: Enlightenment and Revolution, 1550 - 1789

In 1670, Anton van Leeuwenhoek (LAY*vuhn*huk) used a microscope to observe
bacteria and examined blood cells for the first time
o In 1643, Evangelista Torricelli developed the first mercury barometer, a tool for measuring
atmospheric pressures and ___________________________
o In 1714, Gabriel Fahrenheit made the first thermometer to use mercury in glass
o Anders Celsius created another scale for the mercury thermometer in 1742
 Medicine and the Human Body
o During the Middle Ages, European doctors accepted as fact the writings of an ancient Greek
physician named Galen

Galen had never dissected a human body, instead relying on his studies of ________________
________________________, assuming that human anatomy was the same
o A physician named Andreas Vesalius proved Galen wrong

Dissected human corpses and published his observations
o In the late 1700s, British physician Edward Jenner introduced a vaccine to prevent _____________

Jenner discovered that inoculation with germs from a cattle disease called _______________
gave permanent protection from smallpox and it to create the world’s
___________________________
 Discoveries in Chemistry
o Robert Boyle pioneered the use of the scientific method in ___________________

Challenged Aristotle’s theory that the physical world consisted of four elements –
___________________________________________________

Proposed that matter was made up of smaller primary particles that joined
together in different ways