The Scientific Revolution

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Background to the Scientific Revolution

Medieval scientists, “natural philosophers”, relied on ancient scientists, especially Aristotle.

In the Renaissance, the works of Ptolemy became well known.

Technical problems, like calculating the weight a ship could hold, led to a movement toward observation and measurement.

Technology– Telescope and microscope– Printing press

Mathematics – the key to scientific study.

Revolution in Astronomy

Ptolemy – ancient Greek astronomer– Geocentric – Earth at the center of the

universe.– Ptolemaic System – Medieval philosophers

believed Ptolemy’s theory that the earth was surrounded by circular spheres in which the heavens moved.

– The movement of these spheres is what makes the motion of the sun, moon, and stars.

– The heavenly bodies were pure orbs of light.– The tenth sphere was the “prime mover” and

outside that was Heaven, the abode of God.

Claudius Ptolemaeus

Revolution in Astronomy

Nicholas Copernicus – Polish astronomer– Heliocentric – sun at the center.– Copernicus said the earth revolved around the

sun, the moon around the earth, and the earth rotated around its axis.

Johannes Kepler – German mathematician– His observations proved the earth and planets

orbit around the sun in elliptical (oval) orbits.

Copernicus

Kepler

Revolution in Astronomy

Galileo Galilei – Italian astronomer• Observed the sky with a telescope.• Saw mountains on the moon and the moons

of Jupiter.• Proved the planets were material and not just

light.• Galileo got in trouble with the church, which

held to the Ptolemaic System. He was ordered to abandon his findings.

Revolution in Astronomy Sir Isaac Newton – English

mathematician– Three Laws of Motion - inertia

• A body at rest stays at rest until acted upon by a force.

• A body in motion stays in motion until acted upon by a force.

– The Law of Gravity• All matter has mass and is attracted to

other matter.– Newton described a “clockwork universe”

with everything operating like a machine.

Medicine and Chemistry

Galen – Ancient Greek physician.– Galen’s assumptions were

wrong because he used animals to study anatomy.

– Until the 1500s, his writings dominated European medicine.

Medicine and Chemistry

Andreas Vesalius – On the Fabric of the Human Body (1543)

– “The father of anatomy” studied anatomy by dissecting human bodies at the University of Padua in Poland.

– He thought there was two kinds of blood.

William Harvey – On the Motion of the Heart and Blood (1628)

– Proved the heart, not the liver as Vesalius had believed, was the beginning point of the blood’s circulation.

– Showed that the same blood flows through the arteries and veins.

Vesalius

Harvey

Medicine and Chemistry

Anton van Leeuwenhoek– “The father of microbiology” studied water under a

microscope.– He discovered microorganisms.

Robert Boyle– Boyle’s Law – The volume of a gas varies with the

pressure exerted on it. Antoine Lavoiser

– Invented a system for naming the chemical elements.

Van LeeuwenhoekBoyle

Lavoiser

Descartes and Rationalism

Rene Descartes– Said he could be sure of one thing,

his own existence. “I think, therefore I am.”

– Only accepted those things his reason said was true.– The material and mental worlds are different realms.– There is a separation of mind and matter.– “The Father of Modern Rationalism” – believed reason was the source of all knowledge.– the Cartesian coordinate system (x, y) allowing

geometric shapes to be expressed in algebraic equations being named for him.

The Scientific Method

Francis Bacon– Created the scientific method.– Believed science would help conquer nature.

Conclusion

The Scientific Revolution changed the way people looked at the world. Observation, experiment, and reason became the keys to trying to understand the world and solve problems.