The Scientific Revolution

Key Figures

Aristotle

384 BCE - 322 BCE

An ancient Greek philosopher who believed in the geocentric model of the universe with the Earth at the center and the other planets and the sun revolving it. Furthermore, he thought that the orbits of the planets around the Earth were perfectly circular and that the physical laws on Earth were different from the ones in the Heavens. For example, he believed that the motion on Earth was in straight lines. He wrote Physics in 350 BCE.
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Nicolaus Copernicus

1473 - 1543

A Renaissance astronomer and mathematician who proposed that the Earth and other planets revolved around a stationary sun. His heliocentric solar system was controversial, and he is seen as the initiator of the Scientific Revolution. De revolutionibus orbium coelestium (On the Revolutions of the Heavenly Spheres) was published in 1543.
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Tycho Brahe

1546 - 1601

A Danish nobleman who took extremely detailed astronomical and planetary observations before the invention of the telescope. His data was later analyzed by his assistant, Johannes Kepler. Brahe published De nova stella (On the new star) in 1573.
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Galileo Galilei

1564 - 1642

An Italian philosopher, mathematician, physicist, and astronomer who played a central part in the Scientific Revolution. He disproved the Aristotelian theory that the rate at which an object falls is dependent on its weight by dropping two objects of different mass and the same surface area from the Leaning Tower of Pisa. He created the Law of Uniformly Accelerated Motion and his telescope revealed mountains on the moon, phases of Venus, and moons around Jupiter. He supported Copernicus’s beliefs and published Dialogue Concerning the Two Chief World Systems in 1632. Galileo was placed under house arrest by the Roman Catholic Church for his views.
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Johannes Kepler

1571 - 1630

A German astrologer, mathematician, and astronomer who came up with The Three Laws of Planetary Motion using Tycho Brahe’s data. He was a key figure in the Scientific Revolution and published his books Astronomia nova in 1609 and Harmonices Mundi in 1619. He believed firmly in the Copernican view of the universe and discovered that the orbits of the planets were elliptical, not circular.
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Isaac Newton

1642 - 1727

An English physicist and mathematician who discovered the Law of Universal Gravitation which proved that gravity worked the same way on Earth and in the solar system and Newton’s Three Laws of Motion. His Philosophia Naturalis Principia Mathematica was published in 1687 and delineated Newton’s model of the universe as governed by the Law of Universal Gravitation. It is the basis of modern physics and astronomy and integrates the works and discoveries of the great astronomers before Newton.
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Edmond Halley

1656 - 1742

An English astronomer and scientist who calculated the orbit of Halley’s comet. He predicted that the comet would return in 1758, and it did, thus becoming one of the first successful tests of Newtonian physics.
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Henry Cavendish

1731 - 1810

An English experimental physicist and chemist who measured the value of the gravitational constant , which could be used to calculate the mass of the Earth, using a sensitive torsion balance in the Cavendish experiment, performed in 1797.
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