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 • Geocentric model- Used observations • Constructed charts and tables

4. First model to Explain movements of the Planetshttp://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 • Danish Born aristocrat • Duel • Lost part of his nose, used metal to cover it • King Frederick II • Funded observatory run by Tycho • Hven- Island off Denmark • Called Uraniborg- finest observatory in the world • Instrumentation • 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