1. Aristotle 384-322 BC Great Philosopher/Developed Scientific Method Geocentric model of the universe

2. Aristarchus 310-230 BC Greek Astronomer First to propose Heliocentric model

3. Ptolemy AD 85- AD165 Astronomer/ Mathematician Wrote Almagest –G–Geocentric model- Used observations Constructed charts and tables

4. First model to Explain movements of the Planets http://astro.unl.edu/naap/ssm/animations/ptolemaic.swf http://astro.unl.edu/naap/ssm/animations/ptolemaic.swf

5. Copernicus 1473-1543 Wealthy Polish Merchant Derevolutionus orbium coelestium – Book on heliocentric Model First to provide evidence of heliocentric model

6. Tycho Brahe 1546-1601 –D–Danish Born aristocrat Duel –L–Lost part of his nose, used metal to cover it King Frederick II –F–Funded observatory run by Tycho Hven- Island off Denmark –C–Called Uraniborg- finest observatory in the world Instrumentation –D–Designed and Calibrated- Great accuracy Kepler- Hired as an assistant to calculate planetary orbits

7. Uraniborg

8. Kepler 1571-1630 German Mathematician Heliocentric Model – Believed sun was principal source of power in the universe Prague – 1600 Met Tycho Brahe- Became assistant Used Tycho’s observations to predict orbits Planetary Orbits – Know for his prediction of elliptical orbit of mars

9. Kepler’s Planetary Motion elliptical motion elliptical motion 2

10. Galileo 1564-1642 Telescope – Constructed 20x refractor telescope Moons – discovered 4 largest moons of Jupiter in 1610 First observation of satellites orbiting another planet Sunspots – First to observe and correctly explain sunspots Venus – Exhibited a full set of phases resembling our moon Copernican system- Full support

11. Sir Isaac Newton 1643-1727 – English born – Physicist, mathematician, astronomer, philosopher, alchemist, theologian Principia – Published in 1687 Considered most influential book in the history of science – Gravitation law – 3 laws of motion Calculus- Inventor Newton or Einstein – Royal society deemed Newton more influential

12. Newton’s laws of motion First law- "A body persists its state of rest or of uniform motion unless acted upon by an external unbalanced force." Newton's first law is often referred to as the law of inertia. Second law- "Force equals mass times acceleration (F = ma)": the net force on an object is equal to the mass of the object multiplied by its acceleration. Third law - "To every action there is an equal and opposite reaction."

13. Newton Animations 3 Laws of motion animation

14. Edmund Halley 1656-1742 – English born Prove Keplers Laws – Cambridge to work on problem Newton – Already solved Keplers laws- not published Halley convinced Newton to write Principia at Halleys expense Diving Bell- Inventor Halley’s Comet – Predicted comet of 1456, 1531, 1667, 1682 was same comet and would arrive in 1758

15. William Herschel 1738-1822 – German born British Astronomer Telescope Maker – Best telescope builder of his times Uranus – Discovered Planet