The Scientific Revolution

KEY IDEA In the mid-1500s, scientists began to question accepted beliefs and make new theories based on experimentation.

The Science of the Middle AgesDuring the Middle Ages, science was based on the ideas of magic. There were not always rational explanations for the way the world worked.

Alchemists sough to understand and control the natural world through the use of spells and magic formulas. Alchemy arrived in Spain

during the Arabian occupation by the Moors and then spread into the rest of

Europe.

Aristotle’s CosmologyAristotle was an ancient Greek philosopher who arrived at a complex theory of the universe.

Aristotle believed all things in the world are made up of a combination of four elements: Fire, water, air, and earth. Aristotle

The Geocentric UniverseAristotle arrived at the theory that the earth is the center of the universe and that everything revolves around the earth. This is called the geocentric theory of the universe.

This idea fit very well with the teachings of the Church as it put humans center stage.

Earth Centered Universe

During the Middle Ages, few scholars questioned ideas that had always been accepted.

People of the Middle Ages looked at Aristotle and the Bible as the authorities in all mysteries of nature and cosmology (how the universe works). Therefore, people still thought that the earth was the center of the universe and the sun, moon, other planets, and stars moved around it.

Nicolaus CopernicusNicolaus Copernicus was a great Polish scientist in the early 1500s. He studied the stars and planets for many years.He was the first to challenge Aristotle’s geocentric theory of the universe.He is viewed today as the founder of modern astronomy. Nicolaus

Copernicus

Copernicus’s Model of the Universe

Copernicus concluded that the earth, like the other planets, revolved around the sun, and the moon revolved around the earth. In other words, we live in a heliocentric universe.

Fearing attack, he did not publish his findings until just before his death.

Tycho BraheTycho Brahe was a Danish astronomer who carefully recorded the movements of the planets for many years. He was not good enough at mathematics to make sense of his data so he recruited a young mathematician, Johannes Kepler, to interpret of his observations. Tycho Brahe

Johannes Kepler

After Brahe’s death, in the early 1600s, Johannes Kepler used mathematics and Brahe’s data to confirm Copernicus’s

basic idea of a sun-centered universe.

Johannes Kepler

Why Did Mars Move Backwards

Kepler wanted to know why Mars wasn’t where it was supposed to be. He had excellent records of how Mar’s position in the sky seemed to change because of the thorough mathematical records compiled by his mentor Tycho Brahe.

Mars’s position seemed wrong. It did not fit any known theory of planetary movement so Kepler continued to work to work out a better theory.He came up with three principles of planetary motion that are now known as Kepler’s laws.

Kepler’s Laws

Planets orbit the sun in elliptical, not circular, orbits.

Planets move faster when they are closer to the sun.

The sun in not in the exact center of the orbit

Galileo GalileiAn Italian scientist, Galileo Galilei, made several discoveries that undercut ancient ideas.

He made one of the first telescopes and used it to study the planets.

He found that Jupiter had moons, the sun had spots, and Earth’s moon was rough.

New Ideas Intimidate People

Galileo began to publicly challenge Aristotle’s ideas. Aristotle had determined that the moon and the stars were made of pure substances but when Galileo looked through his telescope, he found that moons surface was rough and uneven.He also observed moons orbiting Jupiter. Aristotle believed that the only planet being orbited was earth.Galileo set out to prove Copernicus’ heliocentric theory.

Galileo Goes Public

Galileo published several letters and books supporting the Copernican theory.

In his book, Dialouge Concerning the Chief World Systems, he created a mock debate between the astronomers Ptolemy, Aristotle and Copernicus. In the book, Copernicus, through reason, disproves the cosmology theories of the other two.

The Church Responds

Galileo’s public support of Copernicus frightened both the Protestants and the Catholic Church because his ideas clearly went against religious teachings and the Church’s authority of the mysteries of nature.

In 1633, Galileo was summoned to stand trial before the Inquisition to answer charges of heresy.

Pope Urban VIII

Pope Urban was elected in 1623, he was in all ways a Renaissance man interested in art, music, architecture and scientific discovery. Before he became pope, he had written a sonnet complimenting Galileo on his scientific work.

Unfortunately, after Urban became pope, he could no longer afford to publicly support Galileo because he was in danger of losing his high position. It was Urban who ordered Galileo to stand trial before the Inquisition.

Galileo Recants to Save His Life

At his trial, instruments of torture were set before Galileo in an attempt to get him to sign a confession and recant his statement. It worked. Galileo recanted in exchange for a sentence of spending the rest of his life under house arrest.

In front of the pope, Galileo retracted his support of the heliocentric theory. Although Galileo recanted, it is reported that as he left his meeting with the pope, he shouted “But it does move” reasserting his belief that the earth moves around the sun!

Galileo’s InfluenceGalileo’s observation that a pendulum moves back and forth at a constant rate of speed influenced Dutch mathematician and astronomer Christian Huygens to develop a better clock

    In 1656, Huygens’ first pendulum clock appeared. His new clock lost less than minute each day. This was a major improvement over the existing time pieces that generally lost more than 15 minutes each day.

The Vatican Clears Galileo In 1992, Pope John Paul

II officially acknowledged that Galileo was correct in asserting that the earth revolves around the sun. His pronouncement came after a 13 year study of Galileo’s case by the Vatican Scientific panel.

        

The panel concluded that the church leaders were clearly wrong in condemning Galileo but that they had acted in good faith. The Church defends the decision by asserting that the Church was working within the knowledge of their time (1660s), therefore they could not clearly see how Galileo’s discoveries could go along with their interpretations of the Bible.

    It is clear how new ideas intimidate people and force them to change the way they think!

 

Answer These Questions

1. Who is the famous Greek Philosopher that was regarded as the ultimate authority of the mysteries of nature and the universe?

2. Who was the Polish astronomer who came up with the idea of a heliocentric (sun-centered) universe?

3. Who is the Danish astronomer who collected a great amount of data on the movement of planets and stars?

4. Who is the brilliant mathematician who discovered the governing principles of planetary motion?

5. Who is the astronomer from Italy who first used a telescope to look at the moon and the planets? His observations caused him to question the accepted ideas of Aristotle

2. Copernicus:

Heliocentric model of the universe.

3. Tycho Brahe:

Carefully recorded the movements of the stars and planets.

4. Johannes Kepler

Interpreted Brahe’s data and

discovered the mathematical

laws that govern the

universe.

5. Galileo Galilei

Used a telescope to look into

the heavens. What he

observed disproved Aristotle’s

ideas of the universe.

1. Aristotle

Scholars Begin to Question the Accepted Science

In the mid-1500s, however, attitudes changed. Scholars now started a scientific revolution drawn from a spirit of curiosity.

One factor was the new focus on careful observation. Another was the willingness to question old beliefs. European explorations were a third factor.

Scientific Method

The revolution in scientific thinking that Copernicus, Kepler and Galileo began eventually developed into a new approach to scientific inquiry called the scientific method.

Science Based on Logic and Reason

  The development of the scientific method placed an emphasis on the power of human observation. However, new ideas were not readily accepted.A four step method was developed to conduct scientific experiments:

1. Observation2. For a hypothesis3. Test the hypothesis4. Evaluate, analyze and interpret data

This procedure was based on logical inquiry.

Exploration Leads to Scientific Inquiry

In 1768, the English navigator and mapmaker James Cook set out on the first of three voyages to explore the South Pacific. Cooks voyages were scientific expeditions. These expeditions were sponsored by the Royal Society of London, a group founded in the mid 1600s to encourage the growth of scientific knowledge.

Astronomers, artists and a botanist went with Cook to gather information about the distant parts of the world.

Isaac Newton

Isaac Newton’s contributions to science brought together all of the ideas of the scientists before him. He held the missing pieces.

Inspiration Can Knock You in the Head

Newton was sitting under an apple tree when an apple fell nearby. Newton was in a thoughtful mood that day and he began to wonder why apples always fall to the ground. Why don’t they fall sideways of up? Newton reasoned that the earth must have some power that draws objects to it. This was the beginning of the law of gravity.

The Laws of Universal Gravitation

Newton’s greatest discovery is that the same force ruled the motion of all of the planets, the pendulum and all matter on earth and in space.

The key idea that linked motion in the heavens with motion on the earth was the law of universal gravitation.

According to the law of universal gravitation, every object in the universe attracts every other object.

The attraction depends on the mass of the objects and the distance between them.

Newton described the universe as a giant clock, all of its parts worked together perfectly in ways that could be expressed mathematically.

Newton believed that God was the creator of the orderly universe. God was like a clockmaker who set everything in motion.

Sir Francis Bacon & Empiricism

Francis Bacon (1600s) believed that by better understanding the world, scientists would generate practical knowledge that would improve people’s lives.

Rene Descartes & MathematicsDescartes developed analytical geometry. He was not as interested in scientific experimentation. He believed that mathematics and logic could explain everything in nature. He believed that everything should be doubted until it could be proved by logic and reason.

Rene Descartes

Other Advances in Science

Microscope Zacharias Janssen

Mercury barometer Evangelista Torricelli

Fahrenheit thermometer Garbriel Fahrenheit

Celsius thermometer Anders Celsius

Small pox inoculation Edward Jenner

Discovery of gas oxygen Antoine Lavoisier

Boyle’s Law Robert Boyle

Anton van Leeuwenhoek

This Dutch fabric merchant was the fist to observe microscopic bacteria under the microscope.

A Solution to Smallpox

In the 1600s sand 1700s, Smallpox, a very contagious disease, killed many infants and young children. Those who survived were scarred for life.

In the 1700s, n English writer, Lady Mary Wortley, traveled to Turkey. While in turkey, she observed a woman deliberately exposing her children to smallpox through a small break in the skin.

Lady Wortley

   The woman children all came down with smallpox but in a milder form. This protected them from catching a more virulent case of smallpox later in their lives.

   Lady Wortley was so impressed with this that she had the same treatment applied to her son. She then brought the procedure back to Great Britain and from there it was used all over Europe.   

Smallpox Inoculation

Edward Jenner refined the method using cowpox ( a milder disease that occurred in cows) to create an inoculation that would result in permanent protection from smallpox for humans. The risks from this inoculation were much lower that the one with the live smallpox virus.