1 / 50

2. The Discovery of the Solar System

2. The Discovery of the Solar System. The celestial sphere isn’t real, but it’s a good concept for making maps of the sky. Map of some winter constellations. Geographical coordinates LATITUDE (north – south) LONGITUDE (east-west).

kaiya
Download Presentation

2. The Discovery of the Solar System

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. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) 2. The Discovery of the Solar System

  2. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) The celestial sphere isn’t real, but it’s a good concept for making maps of the sky.

  3. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) Map of some winter constellations

  4. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) Geographical coordinates LATITUDE (north – south) LONGITUDE (east-west)

  5. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) For example, Minneapolis: Latitude 45°N, longitude 93°W (approximately)

  6. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) On a celestial map (sky map) “DECLINATION” replaces latitude (N-S) “RIGHT ASCENSION” replaces longitude (E-W)

  7. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) N E W S Sky map: (Why ??) A puzzle ... Geographical map: N W E S

  8. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) CIRCUMPOLAR stars

  9. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) CIRCUMPOLAR stars

  10. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) CIRCUMPOLAR stars

  11. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) CIRCUMPOLAR stars

  12. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) Next ... Something about TIME (or rather time-keeping)

  13. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) Our LOCAL MERIDIAN

  14. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) Think of our meridian as a fan or sheet, rotating with the Earth:

  15. Ast 1001 lecture 2 -- 2007 Sept 6 (kd)

  16. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) “Solar time”refers to the Sun; approximately the same as ordinary clock time. “Sidereal time”refers to the stars; 1 sidereal day = 23h 56m solar time.

  17. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) In fact, sidereal time = right ascension currently “on the meridian”.

  18. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) ( Remember to mention why sidereal time was formerly used to regulate clocks – genuine solar time was irregular. ) ( Also mention time zones. )

  19. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) Next: The ecliptic and the planets. (The Big Question: Who goes around whom??)

  20. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) THE ECLIPTIC (Sun’s annual path across the constellations)

  21. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) THE ECLIPTIC (Sun’s annual path across the constellations)

  22. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) THE ECLIPTIC: related to Earth’s 23.5-degree tilt

  23. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) The planets stay close to the ecliptic too. In ancient times: -- Mercury -- Jupiter -- Venus -- Saturn -- Mars

  24. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) A crucial trick that planets do: RETROGRADE MOTION

  25. Ast 1001 lecture 2 -- 2007 Sept 6 (kd)

  26. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) Some Greek philosophers were the first to really try to figure out WHAT IS ACTUALLY HAPPENING. (beginning about 600 BCE) The most influential, and almost the last, was CLAUDIUS PTOLEMY – a textbook writer about 1900 years ago.

  27. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) GEOCENTRIC theory ...

  28. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) ... But RETROGRADE MOTION is hard to explain.

  29. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) ... Ptolemy’s solution (actually invented by someone else): EPICYLES

  30. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) “DEFERENTS” and “EPICYCLES”

  31. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) ... and EQUANTS, and G.K.W.E.

  32. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) ... Fall of the Empire, interregnum, the East, medieval, then renaissance...

  33. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) Ptolemy’s theory worked fairly well. The Alphonsine tables...

  34. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) COPERNICUS (?)

  35. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) Copernicus’ contemporaries, c. 1520 ... Martin Luther Henry VIII of England Charles V of the H.R. Empire & Spain Suleiman the Magnificent Magellan Cortez Rabelais ...

  36. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) HELIOCENTRIC !

  37. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) Why heliocentric? Retrograde motion...

  38. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) WHICH WAS RIGHT? Ptolemy, or Copernicus? Geocentric, or Heliocentric? Were there theological or political implications? For more than 70 years no one could think of a way to really answer the question. (Mention some of the arguments)

  39. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) Meanwhile Thomas Digges realized something very important.

  40. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) 1600—1620: GALILEO and KEPLER solved the problem in two different ways. Contemporaries: -- Shakespeare -- Cardinal Mazarin -- James I of England -- Cervantes -- The Virginia and Massachusetts colonists

  41. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) GALILEO

  42. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) What Galileo did...

  43. Ast 1001 lecture 2 -- 2007 Sept 6 (kd)

  44. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) The Moons of Jupiter

  45. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) The Moons of Jupiter

  46. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) The Moons of Jupiter

  47. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) The Phases of Venus

  48. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) The Phases of Venus

  49. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) The Phases of Venus

  50. Ast 1001 lecture 2 -- 2007 Sept 6 (kd) Next topic: Kepler

More Related