Flashcards
Which Person
Cards in this deck (11)
- 1Eudoxus of CnidusProposed a geocentric model of the Universe
Earth was at the center and didn’t move
Other objects in the sky are on a series of crystalline spheres, centered on Earth, turning at different speeds. - 2AristotleStudent of Plato, but differed in that the world of observed phenomena was the real world
Universe had perfect radial symmetry – finite and spherical
Everything that moves in the sky moves in circles – heavens are perfect and circles are perfect
55 crystalline spheres predicted. - 3Aristarchus of SamosMathematician who proposed a Heliocentric Universe!!
Developed a system of measuring relative distances - 4EratosthenesEstimated the circumference of Earth by measuring the shadow cast by the sun at noon at Alexandria while at the same time in Syene (now Aswan) there was no shadow cast on the day of the summer solstice.
Error less than 1%!
Calculated the tilt of Earth’s axis
Calculated the distance of Earth to the Sun
Invented the leap day - 5PtolemyProposed a model for the geocentric universe that could better explain retrograde motion.
Wrote The Almagest (The Greatest) – the only surviving comprehensive ancient treatise on astronomy—compiled and expanded on work of the Chaldeans of Babylonia - 6Nicolaus CopernicusFormulated a comprehensive heliocentric model of the universe.
Published his book De revolutionibus orbium coelestium (On the Revolutions of the Celestial Spheres) on his deathbed in 1543. It is said that he wasn’t so much afraid to publish it based on what people might say, but because he was a perfectionist. - 7Tycho BraheGranted an observatory on the island of Hven, with large astronomical instruments which gave him the ability to take almost 20 years of the most accurate naked eye measures ever.
- 8Johannes KeplerAssistant to Tycho Brahe. Took 20 years of planetary data and derived 3 laws of planetary motion from them.
- 9Galileo GalileiImproved upon the Dutch invention of the telescope and was the first person to look at the sky with this device.
His telescopic discoveries supported the Copernican system of the universe.
Showed that all objects fall at the same rate in a gravitational field (on Earth) with absence of air resistance.
He was put under house arrest for supporting the heliocentric system. - 10Isaac NewtonEnglish physicist, mathematician, astronomer, natural philosopher, alchemist, theologian,
Described 3 laws of motion and the universal law of gravitation.
Showed that motions of objects on Earth and celestial bodies were governed by the same set of natural laws – linked Gravitation w/ Kepler’s 3 Laws of Planetary Motion
Built a reflecting telescope
Shares credit for developing Calculus - 11Edwin HubbleChanged our understanding of the universe profoundly by discovering the existence of galaxies other than our own. (Andromeda)
Hubble’s Law: Discovered that the light spectra from other galaxies was red shifted which increased with proportion to distance indicating that the universe is expanding.