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Dec 17, 1493
Paracelsus is Born
Alchemist who believed that all matters was composed of combinations of 3 principles: salt, sulfur, mercury. Paracelsus challenged the ancient belief that disease is caused by an imbalance of body humor or fluids (blood, phlegm, black bile and yellow bile) arguing that each illness has a specific, external cause.Traditional doctors treated disease by bloodletting to correct the imbalance of humors, Paracelsus prescribed the ingestion of particular chemicals, esp. metals like arsenic and mercury. -
May 24, 1534
Copernicus published On the Revolutions of Heavenly Spheres
Wrote that Ptolemy was mistaken; the earth was not stationary or the center of the universe. The earth rotated on its axis and orbited with the other planets around the sun in perfect circles. This is known as the heliocentric model of the universe. Fearing disapproval from the clergy, Copernicus published his findings only 1543, the year of his death. Both Catholic and Protestant authorities denounced the his system as going against Christianity. This had never been his intention. -
Jan 18, 1543
Andreas Vesalius Published "On the Fabric of the Human Body"
As a student in the University of Paris, he watched human dissections done with the physician reading out of a Roman anatomy book written by Galen while the surgeon would point to specific part of the anatomy. Vesalius decided to do his own dissections using corpses that he and his friends managed to steal from public executions. His work, "On the Fabric of the Human Body" became a classic text of the scientific revolution. -
Dec 14, 1546
Tycho Brahe is Born
Born into Danish nobility, Brahe became famous when he observed a completely new star (nova) that was visible in 1572. Danish king, Friedrich II was impressed with Tycho that he granted him the use of a small island where he built a castle for him with an observatory. Brahe could not accept Copernicus' view. He believed that the planets orbited the sun and the whole system then orbited a stationary earth. -
Jan 22, 1561
Francis Bacon (Lawyer, Politician, Philosopher) is Born
Bacon advocated an inductive approach to knowledge amassing evidence from specific observations to draw general conclusions. In Bacon's view, many philosophical errors arose from beginning with assumed first principles. The inductive method required accumulating data and then, after careful review and experiment, drawing appropriate conclusion. Bacon argued that knowledge was best tested through the cooperative efforts of researchers performing experiments that could be repeated and verified. -
Dec 27, 1571
Johannes Kepler is Born
Kepler was one of Brahe's students, and he formulated laws of planetary motion. Kepler discovered that planets orbited the sun in an elliptical rather than a circular path, which accounted for their movements nearer and farther from the earth He also showed that there was an exact mathematical relationship between the speed with which a planet revolved and its distance from the sun. -
Galileo Built a Telescope
Although he didn’t invent the telescope, he was the first to make extensive observations with it. Galileo saw the moon’s surface was rugged with craters and mountains. He observed Jupiter had moons and that the sun had spots. In 1632 he published Dialogue on the Two Chief Systems of the World, which agreed with the Copernican system, called those who opposed the heliocentric system as simpletons. Galileo was put on trial and he had to renounce his views. -
William Harvey Begins Working at St. Bartholomew's Hospital in London
After years of working in a hospital, Harvey described the entire circulatory system. His work "On the Circulation of Blood" undermined centuries of therapeutic medicine based on bloodletting. Physicians believed that the body’s inability to consume all the blood it produced resulted in congestion and advocated blood-letting as a way to restore health by reducing that congestion. Harvey wrote that blood was not consumed but circulated throughout the body thus new treatments were necessary. -
Rene Descartes Published "Discourse on the Method"
French philosopher and mathematician who was a champion of deductive reasoning. He stated that to solve any intellectual problem, a person should first establish fundamental principles or truths and then proceed from those ideas to specific conclusions. He searched within himself of what he could be sure was clear and distinct knowledge. All that he knew with certainty was that he existed -"I think, therefore I am". From this point of certainty, Descartes deduced God's existence. -
Isaac Newton’s Principia is Published
Newton was one of the brightest minds at the time. He invented calculus and investigated the nature of light; he also formulated 3 laws of motion: inertia, acceleration and action/reaction. While trying to understand optics, he experimented with his own eyes, even pressing a needle between his eyeball and eye socket. He is best known for discovering the law of universal attraction or gravity, which held that the same force holding an object to the Earth also holds planets in their orbits.