Chapter 1 section 5 pp. 54-57

Setting the Scene

• Leaders of the Renaissance and the Reformation looked to the past for models. Humanists turned to ancient classical ideas. Religious reformers were inspired by the Bible and early Christian times. By contrast, the profound change that took place in science in the mid-1500’s pointed ahead, toward a future shaped by a new way of thinking about the physical universe. We call that historical change the Scientific Revolution.

video

Changing Views of the Universe

Until the mid-1500s, Europeans accepted Ptolemy’s theory, that the Earth was the center of the universe.

This theory not only matched what people believed as common sense but also the teachings of the Church.

In the 1500’s & 1600’s startling discoveries radically changed the way Europeans viewed the physical world

5

A Revolutionary Theory• Nicolaus Copernicus in 1543 in

Poland published On the Revolutions of the Heavenly Spheres. This book proposed the heliocentric model of the universe, in which the sun is the center and the planets revolve around it.

• Most experts rejected this theory, if Ptolemy’s reasoning about the Universe was wrong, all things the church taught may be wrong.

• By the late 1500s Tycho Brahe had evidence that supported Copernicus’s theory, he had set up an observatory and carefully observed the sky accumulating data about the movement of heavenly bodies

• Johannes Kepler continued his masters work and calculated the orbit of planets, his work supported the heliocentric view but planets moved in oval shaped orbits not circles.

Galileo

• Foundations for space studies were laid by Copernicus and Kepler

• Galileo Galilei created an astronomical telescope, it had a specially ground lens that allowed him to see the mountains on the moon, fiery spots on the sun, and four moons circling Jupiter “I did discover many particulars in Heaven that had been unseen and unheard of until this our age”

• Galileo’s discoveries put him at odds with other scholars who attacked him because he contradicted ancient views.

• The Catholic Church condemned Galileo because he challenged the idea that the heavens were perfect and unmoving.

• 1633 Galileo was tried before the inquisition, threatened with death unless he withdrew his “heresies” Galileo agreed to publicly state the earth was motionless at the center of the universe, as he left the court he is said to have “Nevertheless, it does move”

A New Scientific Method

• Despite the opposition of religious authorities, by the early 1600s a new approach to science had emerged. Unlike most earlier approaches, it did not rely on authorities like Aristotle or Ptolemy or even the Bible. It depended instead upon observation and experimentation

A Step-by-Step Process

5

-New process required collection of accurately measured data, to explain the data scientists used reasoning to propose a logical hypothesis, or possible explanation. They then tested, retested, observed.-This became the step-by-step process of the scientific method or the process of discovery the painstaking method used to confirm findings and to prove or disprove a hypothesis.

Bacon & Descartes

• Two giants of the Scientific revolution were Francis Bacon [English] and Rene Descartes

• Both rejected Aristotle’s scientific assumptions, they challenged the traditions of universities that tried to make the physical world fit in with the teaching of the Church

• Both argued truth is not known at the beginning of questioning but at the end, after a long process of investigation

• Bacon stressed experimentation and observation, and wanted science to make life better for people

• Descartes emphasized human reasoning as the best road to understanding, in Discourse on the Method he explains how he decided to discard all traditional authorities and search for knowledge, left only with doubt he concluded that the doubter had to exist thus “ I think, therefore I am.

Newton Ties it all Together• In England the young Isaac Newton read

the works of the leading scientific minds, by 24 he had a theory to explain why the planets moved the way they did.

• The story is that he watched an apple fall from a tree and wondered if that same force may control the movements of the planets

• Newton eventually perfected his theory, using math he showed a single force keeps the planets in their orbits around the sun GRAVITY

• 1687 Mathematical Principles of Natural Philosophy was published, explaining the law of gravity, nature follows uniform laws, all motion in the universe can be measured and described mathematically

• Many saw that Newton’s laws linked physics and astronomy for 200 years his laws were supported, then in the early 1900s new theories of the universe called some of the laws into question

• Newton’s laws of motion and mechanics helped to develop Calculus

Chemistry• The magical notions of

medieval alchemists slowly faded and chemistry came into the Scientific Revolution

• Robert Boyle showed the difference between individual elements and chemical compounds

• Explained the effect of temperature and pressure on glass

• Opened the way to modern chemical analysis

Medicine• Medieval physicians relied on the

ancient works by Galen, his work had many errors, because of his limited knowledge of anatomy

• 1543 Andreas Vesalius “On the Structure of the Human Body” which was the first accurate detailed study of human anatomy

• Ambroise Pare [French] new more effective ointment for preventing infection, and a technique for closing wound with stitches

• William Harvey [English] described the circulation of blood for the first time, showed how heart is a pump forcing blood through veins and arteries

• Anthony von Leeuwenhoek [Dutch] perfected the microscope, first person to see cells and microorganisms

Looking Ahead• The rapid advance in science and

technology that began in the 1500s had continued to today. Thinkers like Bacon, Descartes, and Newton applied the scientific method to the pursuit of knowledge. Their work encouraged others to search for scientific laws governing the universe. Such ideas opened the way to the Enlightenment of the 1700s and a growing belief in human progress