html5-img
1 / 29

Sec. 26.2 pg.577-579 Solar System Models GEOCENTRIC Models HELIOCENTRIC Models

Sec. 26.2 pg.577-579 Solar System Models GEOCENTRIC Models HELIOCENTRIC Models Ancient Greeks Europeans. Aristotle Ptolemy Copernicus Galileo Newton Tycho Kepler

ezra-pace
Télécharger la présentation

Sec. 26.2 pg.577-579 Solar System Models GEOCENTRIC Models HELIOCENTRIC Models

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Sec. 26.2 pg.577-579 Solar System Models GEOCENTRIC Models HELIOCENTRIC Models Ancient Greeks Europeans Aristotle Ptolemy Copernicus Galileo Newton TychoKepler Brahe

  2. Aristotle (350 B.C.)Greek • Formulated a picture of the solar system that put Earth at its center with all the other heavenly bodies orbiting around it. GEOCENTRIC model • The orbits were described as perfect circles. • This failed to explain the behavior of the planets, however.

  3. The “Wanderers” • The Greeks would watch the night sky, • The Sun, moon, stars moved predictably in the sky. • BUT, there were five “objects” that did not follow this regular, predictable motion • They’d speed up and slow down • They’d vary in brightness • Once every year, they’d move BACKWARDSfor a month or two!! • They “wandered”, thus called planetes

  4. The retrograde (backward, looping) motion of Mars. A composite image created by superimposing images taken on twenty-nine different dates.

  5. “Wanderers” (planets) • There were five “wanderers” were the planets: Mercury, Mars, Venus, Jupiter, Saturn • They moved in a loop, both forward from west to east (prograde) and • Backward, east to west (retrograde) * Challenge : to construct a solar system model that could explain all the observed motions , be testable and predictable.

  6. Ptolemy (Greek) A.D. 140 • Attempted to find a model of the solar system that explained the motions of the planets. • And that was testable by predicting future motion • Developed the geocentric model into an impressively complex system of “epicycles”. What does this look like?

  7. Ptolemy’s model of the Solar System/Universe Epicycle

  8. To be continued…. • http://www.youtube.com/watch?v=utH-GHH1FT8&feature=related • Ptolomy http://www.youtube.com/watch?v=wGZdaOsuodQ&feature=related The ancient Greeks

  9. Nicholas Copernicus(1500 AD) European The HELIOCENTRIC Model “De RevolutionibusOrbiumCoelestium”

  10. “On the Revolution of the Heavenly Spheres” 1. Earth is NOT the center of “everything.” 2. ALL the planets revolve around the Sun! 3. Stars are much farther away than the Sun 4. The apparent motion of the stars is a result of the Earth’s rotation 5. Any movement of the Sun is due to Earth’s rotation and revolution about the Sun. 6. Retrograde Motion was much simpler to explain. • http://www.youtube.com/watch?v=3d2TjwxmueQ&feature=related

  11. Copernicus Explains Retrograde Motion Planet's apparent path around sky. 6 6 5 5 4 3 Sun 3 2 2 4 Earth 1 Fixed Stars 1 Outer Planet Earth overtakes slow outer planet so the outer planet appears to slow down, move in reverse, and then move forward again with respect to the fixed stars.

  12. Galileo Galilei(1564 – 1642) "Eppur Si Muove“"(And, yet it moves!") 1610 “SideriusNuncius” (The Starry Messenger) Used a handmade telescope to view the sky.

  13. Galileo Galilei (1564 – 1642) Sunspots moved across the face of the Sun, so….. The sun must be rotating spinning) SUNSPOTS

  14. The Moon has mountains, valleys, craters, just like Earth! Galileo Galilei (1564 – 1642)

  15. Jupiter Has Moons! Galileo’s 4 Moons – Io, Europa, Callisto, & Ganymede Jupiter has moon orbiting around it, So….. Do the planets orbit around the Sun Venus has phases, just like our moon! This could only happen if Venus orbited the Sun.

  16. Tycho Brahe (1575) • After seeing the total eclipse on August 21, 1560, and became a master of careful astronomical observations. • Lost part of his nose in a duel and replaced it with a metal one. • Made detailed naked eye observations of the motions of the planets. • In the course of 30 years, he had amassed the best astronomical DATA of the day

  17. Kepler’s 3 Laws of Planetary Motion 1st Law: The orbital paths of each planet is an ellipse, with the Sun at one focus

  18. Johannes Kepler’s(1600) Kepler ‘inherited’ the observations after the sudden death of Tycho Math skills - Kelper's skills were extraordinary. He could not get Tycho'svery careful observations to fit any of the Models of Ptolemy, Copernicus until he used …..

  19. Kepler’s3 Laws of Planetary Motion 2nd Law: An imaginary line connecting the Sun to any planet sweeps out equal areas in equal time.. Area 1 90 days Area 2 90 days Planets have variations in their orbital speed

  20. http://www.physicsclassroom.com/mmedia/circmot/ksl.cfm http://highered.mcgraw-hill.com/olcweb/cgi/pluginpop.cgi?it=swf::800::600::/sites/dl/free/007299181x/78778/Kepler_Nav.swf::Keplers%20Second%20Law%20Interactive

  21. Kepler’s 3rd Law of Planetary Motion The square of a planet’s orbital period is proportional to the cube of its distance. In other words……the farther away the planet, the longer its ‘year’ P2(years) = A3(AU) 1 Astronomical Unit = The Earth-Sun Distance (93 million miles)

  22. Kepler’s Third Law = = = = = = = = =

  23. Kepler’s Thirds Law of Planetary Motion:a planet’s orbital period is proportional to its distance.…the farther away the planet, the longer its ‘year’

  24. Isaac Newton (1642 – 1727) • One of the most brilliant theoreticians to ever live. • Explained WHY the planets move as they do. • He formulated three laws of motion and the law of universal gravitation.

  25. Newton’s 1st Law of Inertia:Objects in uniform straight line motion continue in straight line motion unless an outside force is applied to change their motion Once in orbit, a planet will continueits orbital motion at constant velocity until an outside force (asteroid, another planet?) acts on it to change its orbit.

  26. Newton’s Second Law The ACCELERATION (change in motion) of an object is directly proportional to the net FORCE acting on the object, is in the direction of the net force, and is inversely proportional to the MASS of the object. a = Fnet mass WHY OR F = ma

  27. Newton’s Third Law Whenever one object exerts a force on a second object, the second object exerts an equal and opposite force on the first object. Forces are interacting in PAIRS – one object on another “To every action there is an equal and opposite re-action.”

  28. Law of Universal Gravitation Mass attracts mass Gravityis the FORCE that causes objects to move!

More Related