The Scientific Revolution

1500-1800 Ptolemy.gif

The Renaissance inspired curiosity! Traditional beliefs and ideas began to

be questioned. Many began to

ask… Who am I? What is the

purpose of my life?

The transition from the Middle Ages to early modern times represented a shift in emphasis from “authoritative” truth to “factual” truth.

What does that statement mean? Religious Authority

vs.

Intellectual Authority

Why the conflict?

It was an intellectual revolution:

theories about humanity’s place in the universe

and its connection to the physical world.

Watch it grow from:

Medieval Universities

The Renaissance Ideal

The Scientific Method

Cutting Edge Math and Science Developed… Calculus

Algebra

Physics

Chemistry

Astronomy

Classical and Medieval Views of the Universe

The Earth-centered Universe of Aristotle and Ptolemy held sway on Western thinking for almost 2000 years.

Geocentric Theory:

The sun and all the planets revolve around the earth.

• In the Ptolemaic system, the universe is a series of concentric spheres- spheres one inside the other.

• Earth is fixed, or motionless, at the center of these spheres.

Nicolaus Copernicus (1473-1543)

Worked in secrecy for 30 years to avoid persecution or imprisonment until finally publishing his findings

On the Revolutions of the Heavenly Bodies published as Copernicus lay on his deathbed

Copernicus

Nicolaus Copernicus Nicolaus Copernicus (1473-1543)(1473-1543)

Copernicus proposed that the Sun, not the Earth, was the center of the Solar System. Such a model is called a heliocentric system.

Heliocentric Theory:

The sun is the center of the universe; all planets revolve around it.

See his drawing, next slide…

Let’s see how it works… The idea of Copernicus

was not really new! A sun-centered Solar System had been proposed as early as about 200 B.C. by Aristarchus of Samos (Samos is an island off the coast of what is now Turkey).

However, it did not survive long under the weight of Aristotle's influence and "common sense“

Note: Motion System will not work on

web site in PDF file.

Nicolaus CopernicusThe Earth moves, in two ways.• It rotates on an axis (period = 1 day).• It revolves around the sun (period = 1 year).

The reasons for seasons – the Earth travels around the sun, and its axis of rotation is tilted by 23.5 degrees to the plane of the orbit. In July, the northern hemisphere is getting more sunlight than in January.

The heliocentric model

Anti-Copernican Attacks

• The Bible: Joshua commanded the earth to stand still

• The Earth: too massive to move!

• Motion: why don’t objects spin off?

• Moon: how can the moon orbit the earth and the sun at once?

New Theories About the New Theories About the UniverseUniverse

• German astronomer Kepler provided mathematical proof that the planets revolve around the sun

• But at changing speeds and in ellipses, not at a constant speed and in circles as Copernicus believed

KeplerKepler

Galileo Galilei, Galileo Galilei, (1564-1642)(1564-1642)Created a stir with

his Laws of Motion

Dropped objects from the Leaning Tower of Pisa

Light objects fall at the same speed as heavy objects…

Galileo’s Home Laboratory

Galileo perfected the telescope and saw the moon as no one had before; also Jupiter and …

Galileo’s Own Moon Drawings“It is a most beautiful and

delightful sight to behold the moon.” --Galileo

In 1632 Galileo confirmed Copernicus’s assertion that not all heavenly bodies revolved around the earth but does not publish his findings for over a year!

Pope Urban VIII was outraged and put Galileo on trial

At the trial talks and talks about Copernicus but in his final statement he affirms Ptolemy was right????

However, the Church at that time was not willing to accept his findings.

He had promised the church to uphold the Church’s standings with his research!

Inquisition used to pressure Galileo to recant

Leaving the trial he muttered, “Nevertheless it (earth) does move.”

Church Opposition Galileo and the RevolutioChurch Opposition Galileo and the RevolutionnNew ideas seen as

a threat to church beliefs, doctrines and traditions Church used intimidation, threats to his family and he is put under house arrest for the rest of his life

After recanting some of his views, Galileo helped to establish the universal laws of physics

Sir Isaac Newton, Sir Isaac Newton, (1642-1727)(1642-1727)•Newton developed a

systematic explanation of physical laws based on the findings and theories of the Copernicus, Kepler and Galileo

•His findings explained the movement of the planets with the laws of gravity and inertia

•Knighted in 1705 by Queen Anne

1687 Principia published at his own expense

The universe operates like a giant clock, all parts work together perfectly according to strict scientific laws

God was the creator that set everything in motion

Philosophers Philosophers Support the Support the Revolution Revolution

•Descartes differed from Bacon…

•He believes scientists need to use mathematics and their own minds not so much on the new “method”

•Saw math as the perfect model for clear and certain knowledge

•Only one truth, “I think, therefore I am.”

Rene Descartes

New Ways of New Ways of ThinkingThinking

• English philosopher Francis Bacon helped to develop the scientific method

• Scientific truth should not come from ancient authorities, scientists should use inductive reasoning to learn about nature

Francis Bacon

Experimenting with Chemistry

Irish scientist Robert Boyle primarily responsible for establishing chemistry as a pure science

• English

chemist Joseph Priestly discovered existence of oxygen

Investigating the Human Body

• English scientist Robert Hooke, using a microscope, discovered the cell

Red Blood Cells

Advancements in MedicineOne of the “greats” in

medicine is Andreas Vesalius referred to as the “Luther of medicine.” WHY?

He broke the law, clashed with the church and societal norms to do his research. How?

He climbed a gallows one night to remove a body to study!

Published the first accurate and detailed anatomy book in 1543

Vesalius's dissection of human bodies brought upon him the death sentence for grave-robbing under the Inquisition, a penalty commuted only upon his pilgrimage to the Holy Land.

For hundreds of years, people thought that the heart made blood from food and drink, and the body absorbed it.

An English doctor named William Harvey (1578-1657) showed that the heart recycles blood and acts as a pump to circulate it throughout the body.

Knowledge of the Human Body Expands

Despite new medical discoveries, many doctors still practiced old ways.

Most sick people could not afford to see a trained physician. Instead, they consulted midwives who assisted with childbirths and made herbal remedies to treat illnesses.

• Minor surgeries were not done in the hospital but at the local barbershop.

• Barber-surgeons used the same sharp instruments to cut hair as they did to lance boils, remove warts, extract teeth, and blood-let. Blood-letting is the ancient practice of draining blood out of a person to rid the body of poisons.

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