front 1 Three important ideas developed by the ancient Greeks | back 1 - models of nature - mathematics - theories pertaining to observations |
front 2 Thales (624-546 BC) | back 2 Philosophized about what is the universe made of. Believed the Earth is a flat disk floating in an infinite ocean. |
front 3 Anaximander (610-546 BC) | back 3 Invented the idea of the celestial sphere |
front 4 Pythagoras (560-480 BC) | back 4 First said the Earth is round |
front 5 Democritus (470-380 BC) | back 5 Proposed that the world is built from individual atoms. |
front 6 Plato (428-348 BC) | back 6 Proposed that heavenly objects move in perfect circles at constant speeds. |
front 7 Aristotle (384-322 BC) and Ptolemy (100-170 BC) | back 7 Proposed an Earth-centered universe (geocentric modeling) |
front 8 Heraclides (388-315 BC) | back 8 First to suggest Earth rotates |
front 9 Aristarchus (310-230 BC) | back 9 First to suggest Earth orbits the Sun. |
front 10 Eratosthenes (240BC) | back 10 Measured the size of the Earth using a heliocentric model. |
front 11 Hipparchus (190-120 BC) | back 11 Predicted planetary motion, discovered precession, and invented the magnitude system. |
front 12 Copernicus (1473-1543) | back 12 Proposed a heliocentric model of the universe, but still in perfect circles. |
front 13 Brache (1543-1601) | back 13 Developed Naked-eye observatories |
front 14 Kepler (1571-1630) | back 14 First to figure out that planetary orbits are ellipses, matching Brache's data. |
front 15 Semi-Major axis (Ellipse) | back 15 Half of the long axis of the Ellipse |
front 16 Semi-Minor axis (Ellipses) | back 16 Half of the short axis of the ellipse |
front 17 Eccentricity (Ellipses) | back 17 Describes how stretched an ellipse is relative to a perfect circle |
front 18 Kepler's first law of planetary motion | back 18 The orbit of each planet about the sun is an ellipse, with the sun at one focus |
front 19 Kepler's second law of planetary motion | back 19 A planet moves faster on the part of it's orbit nearer to the sun and slower when it moves farther away, sweeping equal areas within the ellipse in equal amounts of time |
front 20 Kepler's third law of planetary motion | back 20 More distant planets orbit the sun at slower average speeds. P² = a³ P is the orbital period in years a is the average distance from the sun in AU |
front 21 Perihelion | back 21 The point on an eclipse when a planet is closest to the star. a(1 - e) |
front 22 Aphelion | back 22 the point on an Ellipse when a planet is farthest from the star. a(1 + e) |
front 23 Earth is closer to the sun in January than July. Which of the following is true?
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