The Scientific Revolution 1.) Recreate the below chart in your ISN and take notes on each of the 9 scientists in bold letters. You may want to switch it to horizontal. The article is also available on the class website under articles. 2.) Below the chart or on a separate page, define the 10 terms that are underlined. Scientist Traditional Belief Before the Scientific Revolution Revolutionary Idea Major Contributions to Science The Scientific Revolution: Scientific Revolution: a major change in European thought, starting in the mid 1500 s, in which the study of the natural world began to be characterized by careful observation and the questioning of accepted beliefs. Scientific method: a logical procedure for gathering information about the natural world, in which experimentation and observation are used to test hypotheses. Medieval Science Humans have asked questions about nature since ancient times. What was different about the Scientific Revolution of the 16 th and 17 th centuries? And what factors helped bring it about? During the Middle Ages, two major sources guided Europe s thinking about the natural world. The first was the Bible. For Christians, the Bible was the word of God. Whatever the Bible seemed to say about nature must be true. The second source were the teachings of Aristotle. This Greek philosopher had written about nature in the 300 s BCE. In the late Middle Ages, thinkers like Thomas Aquinas combined Aristotle s thinking with the Christian faith. The result was a view of the world that seemed satisfyingly whole. Thomas Aquinas and Aristotle believed that the earth was an unmoving object located at the center of the universe. According to that belief, the
moon, the sun, and the planets all moved in perfect circular paths around the earth. This belief is called geocentric theory. Geocentric theory is also called Ptolemaic Theory after the Greek geographer Ptolemy who wrote an influential book about it. Ptolemy and Aristotle had relied on logic to develop geocentric theoryafter all the earth does not feel as though it is moving and the sun appears to be moving around the earth as it rises in the morning and sets in the evening. To thinkers like Thomas Aquinas, the Bible also seemed to support this view. The Bible taught that God had created man in his own image and placed him at the center. Earth was thus a special place on which the great drama of life took place. The sun, moon and stars were heavenly bodies, separate from earth, revolving around earth, and made perfect and unchanging by the hand of God. Before the Renaissance and the Age of Exploration changed Europe s view of themselves and the world, few Europeans thought to question the traditional authorities of the Bible and Aristotle. The Roots of Modern Science Modern science has its roots in the Renaissance. As we learned previously, a number of previously lost and unknown ancient texts from Greece, Rome and Muslim science were acquired by European scholars. From these ancient texts, Europeans learned about a greater variety of ideas than just those of Aristotle. Scholars read these texts and began questioning the traditional views of the Bible and Aristotle. The idea of humanism gave these scholars a new confidence in their beliefs. The Reformation occurred at the same time in which the authority of the church was being questioned. Finally, the Age of Exploration revealed new lands and people not mentioned in the Bible. All of these changes led Europeans to question their world and traditions and to think about the world in new ways. A New Way of Thinking One of these questioning Europeans was an Englishman named Francis Bacon. Born in 1561, Bacon was a politician and writer who had a passionate interest in science. He encouraged Europeans to look at the world with new and fresh eyes. In his writings, Bacon attacked medieval thinkers such as Thomas Aquinas for relying too heavily on the conclusions of Aristotle and other ancient thinkers. He also criticized ancient Greek thinking and even Aristotle himself. The Greeks had reasoned from abstract theories and logic. Francis Bacon said that knowledge should be gained through experimentation and observation. Scientists, he wrote, should observe the world and gather information about it first. This approach is called empiricism, or the experimental method. Empiricism is the theory that all knowledge is gained from sense-experience. If I can not see it, it does not exist. Bacon believed that by using this method, science could generate practical knowledge that could improve people s lives. In France, the mathematician Rene Descartes also took a keen interest in science. He developed two key ideas. First, Descartes believed the physical universe obeyed universal mathematical laws. As such, science had to include math if it hoped to understand the natural world. Today, much of science is based on
quantitative data, or data dealing with numbers or things that can be measured. He combined algebra and geometry into the new field of analytical geometry (you may have heard of Cartesian points and the Cartesian plane, both named for Descartes). Secondly, like Bacon, Descartes also believed that scientists needed to reject old assumptions and teachings based on tradition. While the theologians of his time started with faith, Descartes started with doubt. He believed that everything should be doubted until proved by logic. The only thing he knew for certain was that he existed- I think therefore I am. From this starting point, Descartes wanted to build knowledge from the ground up. Modern scientific method is based on the ideas of Bacon and Descartes. Scientific Revolutionaries would take the ideas of Descartes and Bacon- observation, experimentation, logic and mathematics- to discover new truths about the universe and humanity s place within it. However, these new discoveries would bring them into conflict with the old authorities. A Revolutionary Model of the Universe The Scientific Revolution can truly be said to have started with one man- a Polish monk named Nicholas Copernicus. Copernicus was a true Renaissance man. He studied law and medicine and earned a PhD in canon law, but in his spare time he studied astronomy. His spare time hobby would lead to a new theory that would change Europe s view of the universe. Copernicus applied Bacon s scientific method to astronomy. Based on 25 years of astronomical observations, Copernicus proposed a theory which placed the sun at the center of the universe. This theory is called heliocentric theory. Earth and the other planets, Copernicus said, traveled in circles around the sun. Earth also turned on its axis every 24 hours. This turning explained why heavenly objects seemed to move across the sky. Copernicus recorded his observations and his ideas in a book. However, he waited nearly 20 years to publish his work. Copernicus knew that his ideas would upset people, in particular the Catholic Church. As you will recall, the Church believed that Aristotle and Ptolemy s geocentric theory agreed with the Biblical idea of man at the center. Copernicus knew that he would be attacked by both scientists and theologians but he also believed deeply that his observations were correct. He agonized over whether or not to publish. Finally, as he was approaching death, he decided to publish his life s work. On the Revolution of the Heavenly Bodies was published in 1543, the year Nicolas Copernicus died. The book was later banned by the Catholic Church. Despite the ban, other scientists read Copernicus theory and tried to test them themselves. One of them was Johanes Kepler. Kepler applied Descartes idea that the universe followed mathematical laws. Applying heliocentric theory, Kepler demonstrated mathematically that the planets move around the sun. He also made a change to the Copernican view of the solar system. Based on his math, Kepler concluded that the planets move in ellipses around the sun, not in perfect circles. The view that the universe was in perfect harmony was beginning to break down.
The idea that the planets are perfect and unchanging would further be challenged when Galileo would view the sun, moon and planets in a way no one had before- through the lens of a telescope. We will learn about Galileo later in this unit. Isaac Newton: The Greatest Scientist of All Time Copernicus, Kepler and Galileo shattered medieval science. However, they also left science a jumble of seemingly unrelated facts that could not be easily applied. It was Isaac Newton who brought all these facts together into a single unified theory that set science on a new course straight into the 20 th century. Born in England on Christmas Day, 1642, the same year Galileo died, Isaac Newton would make all of his major discoveries before the age of 27. Each discovery alone would have made Newton a famous scientist. His first discovery was in optics where he discovered that ordinary white light is a mixture of all the colors of the rainbow. This revolutionized the way scientists see light. Secondly, Newton invented calculus, the seed out of which modern mathematical theory has grown and an essential tool to the development of all science to follow. Calculus is the branch of mathematics that deals with limits and the differentiation and integration of functions of one or more variables. This method allows for modeling systems in which there is change. Newton s most important discoveries however were in the field of physics.
While sitting in an apple orchard, Newton observed apples falling from a tree. This observation gave him a new idea. What if the same forces that made an apple fall to the ground could also be applied to the movement of the planets. Aristotle had believed that the physical laws of the earth were vastly different from those that governed the rest of the universe. Newton believed that material objects moved the same way regardless where they were. The key idea that linked motion in the heavens with motion on the earth was the law of universal gravitation. According to this law, 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. In 1687, Newton published his laws of motion in a book called Mathematical Principles of Natural Philosophy- one of the most important scientific works ever written. Newton described a universe that was like a beautifully designed machine, all of its parts working together like a giant clock and all following mathematical principles that applied on earth as well as the rest of the universe. People began referring to God as the master clockmaker. The same mathematical laws applied everywhere. All people had to do was discover them. This idea of scientific law, or statements based on repeated experimental observations that describe some aspect of the universe, was finally proved by Newton. Scientists everywhere began to search for more natural laws and were inspired by Newton to apply them to fields as diverse as economics and politics. Not until the 20 th century would Newton s ideas be questioned. Others Advance Chemistry, Biology, Medicine and More Astronomy was not the only field that the ancients were mistaken about. Aristotle for example thought there were just four elements- earth, wind, fire and water. It was not until the Scientific Revolution that scientists such as Robert Boyle began to question this idea. Boyle is known as the father of chemistry because he argued that matter was made up of smaller primary particles than Aristotle s four elements. Boyle argued that these particles joined together in different ways. Although Boyle did not know what all these particles were, he set chemists on a search to find them which eventually led to the many elements of the Periodic Table.
Another ancient thinker whose ideas were overturned during the Scientific Revolution was the ancient doctor named Galen. During the Middle Ages, European doctors had accepted as fact the writings of an ancient Greek physician. However, Galen had never dissected the body of a human being. Instead, he had studied the anatomy of pigs and other animals. Galen assumed that human anatomy was much the same. Galen s assumptions were proved wrong by Andreas Vesalius, a Flemish physician. Vesalius said that doctors should observe human anatomy first hand. In 1534, he dissected actual human bodies. Vesalius disproved several of Galen s theories about the workings of the human body and published detailed drawings of human anatomy. These drawings were so accurate and so widely used that Vesalius is known as the father of modern human anatomy. Anatomy is the branch of science concerned with the bodily structure of humans, animals, and other living organisms. Another major discovery of the Scientific Revolution was made by Antonie van Leeuwenhoek who discovered a whole new world previously unknown. Before the Scientific Revolution, it was assumed that all animals in existence had always existed and were on Noah s Ark. The Age of Exploration discovered thousands of new species in the Americas and this theory began to break down. However, it was still believed that all animals could be seen with the human eye. Secondly, it was believed that some animals spontaneously generated out of nothing and the process of fermentation was considered a miracle. Antonie van Leeuwenhoek discovered what he called tiny animals. For most of his adult life Leeuwenhoek held a minor post with the town government but his passion were lenses and looking at small objects. Although he did not invent the microscope, he improved it greatly and was able to magnify objects 500 times. His greatest discovery came in 1674 when he made his first observation of microbes. A microbe is any living organism that spends its life at a size too tiny to be seen with the naked eye. Microbes include bacteria and archaebacteria, protists, some fungi and even some very tiny animals that are too small to be seen without the aid of a microscope. They are the oldest form of life on earth. Leeuwenhoek was the first to see this world. Although
he did not know it yet, this new world was of very great importance to human beings, indeed it often held the power of life and death. Once he had discovered microbes, he started to find them everywhere- in food, on plants, and even in his mouth. He exclaimed, though some thought he was crazy, There are more creatures living on my tongue than there are people in all of Holland! He would be the first to see blood cells and spermatozoa both of which would later explain the human immune system and how life was created. Finally, his examination of grubs, maggots and other such organisms showed that they did not come to life spontaneously, as was previously thought. Rather, they were immature insects. This tiny world, first seen by Leeuwenhoek, is still at the cutting edge of science and our understanding of life and human health. Technology of the Scientific Revolution Galileo said, Measure what is measurable, and make measurable what is not so. Science, as Descartes argued, is based on numbers. The Scientific Revolution would not have been possible without advancements in technology that allowed humans to see and measure new things. While Galileo contributed to the telescope, and Leeuwenhoek to the microscope, other scientists found ways to measure the previously unmeasurable. Evangelista Torricelli in 1643 developed the first mercury barometer, a tool for measuring atmospheric pressure and predicting weather. In 1714, the Dutch physicist Daniel Gabriel Fahrenheit made the first thermometer to use mercury in glass. Previously, temperature could not be measured accurately and scientists could only use vague terms like hot, very hot, etc. Fahrenheit used the fact that mercury expands when heated to develop a temperature scale. He set freezing at 32 degrees. A Swedish astronomer, Anders Celsius, created another scale for the mercury thermometer which he believed was simpler and placed freezing at 0 degrees. These technological developments allowed scientists to see and measure previously unmeasurable phenomena. Today, major scientific breakthroughs continue to rely on advancements in technology.