The Scientific Revolution

Introduction 1300-1600 was a time of great change in Europe The Renaissance, a rebirth of learning and the arts, inspired

a spirit of curiosity in many fields Scholars began to question ideas that had been accepted for

hundreds of years Meanwhile the religious movement known as the

Reformation prompted followers to challenge accepted ways of thinking about God and salvation

While the Reformation was taking place, another revolution in European thought had begun, on that would permanently change how people viewed the physical world

Roots of Modern Science

Before 1500, scholars generally decided what was true or false by referring to an ancient Greek or Roman author or to the Bible – few European scholars challenged the scientific ideas of ancient thinkers or the Church

The Medieval View: - Earth was an immovable object located in center of the universe - The moon, sun, and planets all moved in perfectly circular paths

around the earth - This earth-centered view of the universe was called the geocentric

theory, which came from Aristotle. Ptolemy expanded the theory. - Christianity taught that God had deliberately placed earth at the

center of the universe

A New Way of Thinking

Mid-1500s – a few scholars published works that challenged the ideas of the ancient thinkers and the Church

As these scholars replaced old assumptions with new theories, they launched a change in European thought that historians call the Scientific Revolution

It was a new way of thinking about the natural world based upon careful observation and a willingness to question accepted beliefs

What Led to New Way of Thinking?

During Renaissance, European explorers traveled to Africa, Asia, and the Americas – these lands were inhabited by peoples and animals previously unknown in Europe – this opened up possibilities that there were new truths to be found

Invention of the printing press helped spread challenging ideas among Europe’s thinkers

Age of European exploration also fueled scientific research, especially in astronomy and mathematics – as scientists looked more closely at the world around them, they made observations that did not match their ancient beliefs

Revolutionary Model of the Universe

The Heliocentric Theory was forwarded by Nicolaus Copernicus, a Polish cleric and astronomer

After studying planetary movements for 25 years, he reasoned that the stars, earth, and other planets revolved around the sun

His theory did not completely explain why the planets orbited the way they did

He knew that most scholars and clergy would reject his theory because it contradicted their religious views – so he didn’t publish his On the Revolutions of the Heavenly Bodies until the last years of his life

Copernicus’s book caused little stir at first

Building on Copernicus

Tycho Brahe recorded the movements of the planets for many years and produced a mountain of accurate data based on his observations

Johannes Kepler, a mathematician, studied Brahe’s data and concluded that certain mathematical laws govern planetary motion – one of these laws showed that planets revolve around the sun in elliptical orbits instead of circles

Galileo Galilei Galileo, an Italian scientist, built his own

telescope and used it to study the heavens in 1609

1610: he published Starry Messenger, which described his astonishing observations: Jupiter had four moons, the sun had dark spots, earth’s moon had a rough, uneven surface – this shattered Aristotle’s theory that the moon and stars were made of a pure, perfect substance

Galileo clearly supported Copernicus and his theory

Conflict with the Church

Galileo’s findings frightened Catholic and Protestant leaders because they went against Church teaching and authority – if people believed the Church wrong about this, they could question other Church teachings as well

1616: Catholic Church warned Galileo not to defend the ideas of Copernicus. He remained publicly silent, but continued his studies

1632: He published Dialogue Concerning the Two Chief World Systems which presented the ideas of both Copernicus and Ptolemy, but it clearly showed whose theory he supported

The pope summed Galileo to Rome to stand before the Inquisition. Under threat of torture, he agree ideas of Copernicus were false. He was never a free man after that – under house arrest until his death.

1992: The Catholic Church officially acknowledged that Galileo had been right

The Scientific Method The Scientific Method is a logical procedure for

gathering and testing ideas. Steps in the Scientific Method: 1) Begins with problem arising from observation 2) Scientists form hypothesis, or unproved assumption 3) Hypothesis is tested in an experiment or on data 4) Scientists analyze and interpret data to reach a new conclusion – which confirms or disproves hypothesis

Bacon and Descartes Helped advance the scientific method Francis Bacon: attacked medieval scholars for relying too

heavily on Aristotle and other ancient thinkers. He urged scientists to experiment and then draw conclusions on ancient theories. This approach is called empiricism, or the experimental method.

Rene Descartes: He developed analytical geometry which was an important tool for the new scientific research. He believed scientists had to reject old assumptions. But he approached gaining knowledge differently than Bacon. Rather than using experimentation, he relied on mathematics and logic. He believed everything should be doubted until proved by reason. “I think, therefore I am”

Newton’s Laws Newton helped to bring together the breakthroughs of Copernicus,

Kepler, and Galileo under a single theory of motion. Newton was certain that all physical objects were affected equally by

the same forces. His great discovery was that the same force ruled motion of the planets and all matter on earth and in space.

The key idea that linked motion of the heavens with motion on earth was the law of universal gravitation. According to his theory, every object in the universe attracts every other object. The degree of attraction depends on the mass of the objects and the distance between them.

Newton’s universe was described as a giant clock – its parts all worked together perfectly in ways that could be expressed mathematically. Newton believed that God was the creator of this orderly universe, the clockmaker who had set everything in motion.

The Scientific Revolution Spreads

Scientific Instruments invented: - Zacharias Janssen: the first microscope, 1590 - Anton van Leeuwenhoek: used microscope to observe bacteria; examined red blood cells for the first time - Evangelista Torricelli: developed first mercury barometer to measure atmospheric pressure and predicting weather - Gabriel Fahrenheit: made first thermometer to use mercury in glass; showed water freezing at 32 degrees - Anders Celsius: created another scale for mercury thermometer in 1742;

showed freezing at 0 degrees

Medicine and the Human Body

European doctors had accepted writings of Greek physician Galen during Middle Ages

Galen had never dissected the body of a human being but studied the anatomy of pigs and other animals and assumed the human anatomy was much the same

Andreas Vesalius proved Galen’s assumptions wrong. He dissected human corpses and published his observations.

1700s: Edward Jenner introduced a vaccine to prevent smallpox using an inoculation of live smallpox germs from cowpox – this would give permanent protection from the disease

Chemistry Robert Boyle: father of modern chemistry Challenged Aristotle’s idea that the physical

world consisted of four elements – earth, air, fire, and water

Boyle proposed that matter was made up of smaller primary particles that joined together in different ways

Boyle’s law: explains how the volume, temperature, and pressure of gas affect each other