1 / 19

The War of the ‘Centrics !

The War of the ‘Centrics !. Topics: Geocentric vs. Heliocentric Origins The THREE CONUNDRUMS of the Solar System. What’s the difference between the ‘Centrics?????. Heliocentric Geocentric Which one is right? How do you know???. Modern science starts with the Greeks….

cassie
Download Presentation

The War of the ‘Centrics !

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. The War of the ‘Centrics! Topics: Geocentric vs. Heliocentric Origins The THREE CONUNDRUMS of the Solar System.

  2. What’s the difference between the ‘Centrics????? HeliocentricGeocentric Which one is right? How do you know???

  3. Modern science starts with the Greeks… • Based most of their thinking on observation and reason. • The universe beyond Earth was perfect, beautiful, and unchanging! • Geometry was the math of the day. • Circles were considered the “perfect” shape!

  4. Pythagoras (569-475 BC) • Geometry! a2 + b2 = c2 • Earth is a sphere…which is a perfect figure! • Planetary motion is governed by geometric laws. • Geometry begets HARMONY!

  5. PLATO (428-348 BC) According to Plato, each of these 5 elements occupied a unique place in the heavens!

  6. Plato’s Universe • This was the beginning of the Periodic Table! • Heavy stuff was located closer to Earth. • Lighter stuff occupied space at higher locations.

  7. Aristotle (384-322 BC) • His model is based on Plato’s five solids and his own ideas on motion…harmony, a natural state of rest, blah, blah. • Aristotle’s model of the universe is called CRYSTALLINE SPHERES. • Two moving spheres…one holding the planets…the other holding the stars…Earth in the middle. • All motion is circular with constant speed…nothing ever changes!

  8. SPHERE…SHMERE • Why isn’t the Earth flat in these early models????? • Who is Eratosthenes (276-194 BC)??? • Why is the Earth at the center of the Plato-Aristotelian models?

  9. ARISTARCHUS (270 BC) • Measured the size of the Sun. • First to propose a Heliocentric Model of the Universe.

  10. Back to the drawing board… Aristarchus’ model went south and Aristotle’s was back in action. But, there were problems. Ahhhh…the CONUNDRUMS! • Retrograde Motion 2. Varying Speed of Planets

  11. Retrograde Motion Planets seem to change direction! What’s THAT all about?????

  12. The other one… The planets seemed to move faster at different times. How could this be if everything in the universe moved with CONSTANT circular motion??? Could it be that Aristotle’s reign is coming to an end???

  13. Enter…Ptolemy (~120 AD) • Geocentric Model! • Used epicycles to explain retrograde motion. • Maintained circular motion! • Published book: Algamest Retrograde Animation

  14. What about that changing speed thing??? The Equant • Ptolemy moved the Earth off-center! Now the epicycles moved relative to an imaginary point called the EQUANT! • Does this explanation violate “uniform celestial motion”…? Silence is Golden

  15. Things get too complicated… Ptolemy got some mileage out of his model – it dominated for over a millennium! But, as new data rolled in, it made less sense. And it was frequently tweaked, which made it very complicated!

  16. Copernicus (1473-1543 ) • Heliocentric Model! • Maintained circular motion!

  17. But, WAIT! A new problem emerges in this model!!!! While Copernicus solves the first two conundrums, he creates a new one… PARALLAX!!!! Copernicus vs. Conundrums Compare the 'Centrics Copernicus’ model naturally explained retrograde motion and, to some degree, the varying speeds of planets. Copernicus had to keep the epicycles…though, there weren’t nearly as many!

  18. Parallax…Conundrum #3 • If the Earth were actually on an orbit around the sun, why wasn’t a parallax effect observed???? • What other issues may have posed problems for the sun-centered model?

  19. WHO WON???? The story continues.

More Related