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7th Grade Social Studies / Lesson 5 - Scientific Revolution

What will we be learning in this unit?

  • How did astronomers change the way people viewed the universe?
  • What was the new scientific method?
  • What advances did Newton and other scientists make?


 Changing Views of the Universe

 

  • Until the mid-1500s, European scholars accepted the theory of the ancient Greek astronomer Ptolemy. Ptolemy taught that the Earth was the center of the universe. Not only did this view seem to agree with common sense, it also matched the teachings of the Church. In the 1500s and 1600s, some startling discoveries radically changed the way Europeans viewed the physical world. 
  • In 1543, Polish scholar Nicolaus Copernicus published On the Revolutions of the Heavenly Spheres. In it, he proposed a heliocentric, or sun-centered, model of the universe. The sun, he said, stood at the center of the universe. The Earth was just one of several planets that revolved around the sun.


Changing Views of the Universe

  • Most experts rejected this revolutionary theory. In Europe at the time, all scientific knowledge and many religious teachings were based on the arguments developed by classical thinkers. If Ptolemy's reasoning about the planets was wrong, they believed, then the whole system of human knowledge might be called into question. But in the late 1500s, the Danish astronomer Tycho Brahe provided evidence that supported Copernicus's theory. Brahe set up an astronomical observatory. Every night for years, he carefully observed the sky, accumulating data about the movement of the heavenly bodies.


 Changing Views of the Universe

 

  • After Brahe's death, his assistant, the brilliant German astronomer and mathematician Johannes Kepler, used Brahe's data to calculate the orbits of the planets revolving around the sun. His calculations supported Copernicus's heliocentric view. At the same time, however, they showed that each planet did not move in a perfect circle, as both Ptolemy and Copernicus believed, but in an oval-shaped orbit called an ellipse. 
  • Scientists of many lands built on the foundations laid by Copernicus and Kepler. In Italy, Galileo Galilei assembled an astronomical telescope. As you have read, he observed the four moons of Jupiter moving slowly around that planet-exactly, he realized, the way Copernicus said that the Earth moved around the sun.


Changing Views of the Universe

  • Galileo's discoveries caused an uproar. Other scholars attacked him because his observations contradicted ancient views about the world. The Church condemned him because his ideas challenged the Christian teaching that the heavens were fixed, unmoving, and perfect. 
  • In 1633, Galileo was tried before the Inquisition. Threatened with death unless he withdrew his "heresies," Galileo agreed to state publicly that the Earth stood motionless at the center of the universe. "Nevertheless," he is said to have muttered as he left the court, "it does move."


 A New Scientific Method

 

  • The new approach to science required scientists to collect and accurately measure data. To explain the data, scientists used reasoning to propose a logical hypothesis, or possible explanation. They then tested the hypothesis with further observation or experimentation. Complex mathematical calculations were used to convert the observations and experiments into scientific laws. After reaching a conclusion, scientists repeated their work at least once-and usually many times-to confirm their findings. This step-by-step process of discovery became known as the scientific method.


A New Scientific Method

 

  • The new scientific method was really a revolution in thought. Two giants of this revolution were the Englishman Francis Bacon and the Frenchman Ren© Descartes. Each devoted himself to the problem of knowledge. 
  • Both Bacon and Descartes rejected Aristotle's scientific assumptions. They also challenged the scholarly traditions of the medieval universities that sought to make the physical world fit in with the teachings of the Church. Both argued that truth is not known at the beginning of inquiry but at the end, after a long process of investigation.


  A New Scientific Method

  • Bacon and Descartes differed in their methods, however. Bacon stressed experimentation and observation. He wanted science to make life better for people by leading to practical technologies. Descartes emphasized human reasoning as the best road to understanding. In his Discourse on Method, he explains how he decided to discard all traditional authorities and search for provable knowledge. Left only with doubt, he concluded that the doubter had to exist and made his famous statement, "I think, therefore I am."


 Newton ties it all together

  • As a student in England, Isaac Newton devoured the works of the leading scientists of his day. By age 24, he had formed a brilliant theory to explain why the planets moved as they did. According to one story, Newton saw an apple fall from a tree. He wondered whether the force that pulled that apple to the Earth might not also control the movements of the planets. 
  • In the next 20 years, Newton perfected his theory. Using mathematics, he showed that a single force keeps the planets in their orbits around the sun. He called this force gravity.


Newton ties it all together

 

  • In 1687, Newton published Mathematical Principles of Natural Philosophy, explaining the law of gravity and other workings of the universe. Nature, argued Newton, follows uniform laws. All motion in the universe can be measured and described mathematically. 
  • To many, Newton's work seemed to link physics and astronomy, to bind the new science as gravity itself held the universe together
  • For over 200 years, Newton's laws held fast. In the early 1900s, startling new theories of the universe called some of Newton's ideas into question. Yet Newton's laws of motion and mechanics continue to have many practical uses. Newton also helped develop an important new branch of mathematics-calculus.


Other Scientific Advances

  • The 1500s and 1600s saw breakthroughs in many branches of science. Some of the most significant advances occurred in chemistry and medicine.
  • Chemistry slowly freed itself from the magical notions of medieval alchemists, who had believed it was possible to transform ordinary metals into gold. In the 1600s, Robert Boyle distinguished between individual elements and chemical compounds. He also explained the effect of temperature and pressure on gases. Boyle's work opened the way to modern chemical analysis of the composition of matter.


 Other Scientific Advances

 

  • Medieval physicians relied on the ancient works of Galen. Galen, however, had made many errors, in part because he had limited knowledge of human anatomy. During the Renaissance, artists and physicians made new efforts to study the human body. In 1543, Andreas Vesalius published On the Structure of the Human Body, the first accurate and detailed study of human anatomy. A French physician, Ambroise Par©, developed a new and more effective ointment for preventing infection. He also developed a technique for closing wounds with stitches.


Other Scientific Advances

  • In the early 1600s, William Harvey, an English scholar, described the circulation of the blood for the first time. He showed how the heart serves as a pump to force blood through veins and arteries. Later in the century, the Dutch inventor Anthony van Leeuwenhoek perfected the microscope and became the first human to see cells and microorganisms. These pioneering scientists opened the way for further advances.