astr 1101 001 spring 2008 l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
ASTR 1101-001 Spring 2008 PowerPoint Presentation
Download Presentation
ASTR 1101-001 Spring 2008

Loading in 2 Seconds...

play fullscreen
1 / 24

ASTR 1101-001 Spring 2008 - PowerPoint PPT Presentation


  • 142 Views
  • Uploaded on

ASTR 1101-001 Spring 2008. Joel E. Tohline, Alumni Professor 247 Nicholson Hall [Slides from Lecture12]. Contrasting Models of Planetary Motions. Greek Geocentric Model (Ptolemaic System) – §4-1 Originated by Apollonius of Perga & Hipparchus in 2 nd century B.C.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'ASTR 1101-001 Spring 2008' - liam


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.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
astr 1101 001 spring 2008

ASTR 1101-001Spring 2008

Joel E. Tohline, Alumni Professor

247 Nicholson Hall

[Slides from Lecture12]

contrasting models of planetary motions
Contrasting Models of Planetary Motions
  • Greek Geocentric Model (Ptolemaic System) – §4-1
    • Originated by Apollonius of Perga & Hipparchus in 2nd century B.C.
    • Expanded upon by Ptolemy in 2nd century A.D.
  • Copernican Heliocentric Model – §4-2
    • Proposed in 1543 by Nicolaus Copernicus
    • (Also considered in 3rd century B.C. by Aristarchus)
contrasting models of planetary motions3
Contrasting Models of Planetary Motions
  • Geocentric Model
    • Underlying hypothesis: Earth is unmoving and at “center of the universe”
  • Heliocentric Model
    • Preferred (by Copernicus) initially because of its relative simplicity
    • Eventually proven correct by new observations made possible by the aid of telescopes (see Galileo’s discoveries §4-5)
naked eye observations explained by both ptolemy and copernicus
Naked-Eye Observations“explained” by both Ptolemy and Copernicus
  • Stars (and Sun, Moon, etc.) rise in east and set in west once every 24 hours
  • Remove 24-hr diurnal motion; Sun and Moon both move steadily west-to-east at different rates (Moon = month period; Sun = year period)
  • Superior planets [Mars, Jupiter, Saturn] usually wander slowly east-to-west (observed periods greater than 1 year) but periodically display retrograde (west-to-east) motion
  • Inferior planets [Mercury, Venus] never wander very far (in angular separation) from the Sun; only seen shortly before or shortly after sunrise/sunset
galileo s new observations made with the aid of a telescope 1610
Galileo’s New Observationsmade with the aid of a telescope (~ 1610)
  • Revolutionary discoveries not especially relevant to the “geo-” versus “helio-” centric debate:
    • Mountains and Craters on the Moon
    • Sunspots on the Sun (ouch!)
    • Rings of Saturn
    • The “Milky Way” is “a mass of innumerable stars”
galileo s new observations made with the aid of a telescope 16107
Galileo’s New Observationsmade with the aid of a telescope (~ 1610)
  • Revolutionary discoveries not especially relevant to the “geo-” versus “helio-” centric debate:
    • Mountains and Craters on the Moon
    • Sunspots on the Sun (ouch!)
    • Rings of Saturn
    • The “Milky Way” is “a mass of innumerable stars”
galileo s new observations made with the aid of a telescope 16108
Galileo’s New Observationsmade with the aid of a telescope (~ 1610)
  • Revolutionary discoveries not especially relevant to the “geo-” versus “helio-” centric debate:
    • Mountains and Craters on the Moon
    • Sunspots on the Sun (ouch!)
    • Rings of Saturn
    • The “Milky Way” is “a mass of innumerable stars”
galileo s new observations made with the aid of a telescope 16109
Galileo’s New Observationsmade with the aid of a telescope (~ 1610)
  • Revolutionary discoveries not especially relevant to the “geo-” versus “helio-” centric debate:
    • Mountains and Craters on the Moon
    • Sunspots on the Sun (ouch!)
    • Rings of Saturn
    • The “Milky Way” is “a mass of innumerable stars”
galileo s new observations made with the aid of a telescope 161010
Galileo’s New Observationsmade with the aid of a telescope (~ 1610)
  • Revolutionary discoveries not especially relevant to the “geo-” versus “helio-” centric debate:
    • Mountains and Craters on the Moon
    • Sunspots on the Sun (ouch!)
    • Rings of Saturn
    • The Milky Way is “a mass of innumerable stars”
galileo s new observations made with the aid of a telescope 161011
Galileo’s New Observationsmade with the aid of a telescope (~ 1610)
  • Discoveries useful in resolving the “geo-” versus “helio-” centric debate:
    • Venus exhibits phases like those of the Moon
    • The apparent size of Venus was related to the planet’s phase (as well as to the planet’s angular distance from the Sun)
    • Jupiter has four “Galilean satellites”; their orbital behavior is like a Copernican system in miniature
galileo s new observations made with the aid of a telescope 161012
Galileo’s New Observationsmade with the aid of a telescope (~ 1610)
  • Discoveries useful in resolving the “geo-” versus “helio-” centric debate:
    • Venus exhibits phases like those of the Moon
    • The apparent size of Venus was related to the planet’s phase (as well as to the planet’s angular distance from the Sun)
    • Jupiter has four “Galilean satellites”; their orbital behavior is like a Copernican system in miniature
slide16

Phases of Venus expected in the

Coperican Heliocentric model

galileo s new observations made with the aid of a telescope 161018
Galileo’s New Observationsmade with the aid of a telescope (~ 1610)
  • Discoveries useful in resolving the “geo-” versus “helio-” centric debate:
    • Venus exhibits phases like those of the Moon
    • The apparent size of Venus was related to the planet’s phase (as well as to the planet’s angular distance from the Sun)
    • Jupiter has four “Galilean satellites”; their orbital behavior is like a Copernican system in miniature
slide19

Angular size “a”

expressed

in arcseconds.

galileo s new observations made with the aid of a telescope 161020
Galileo’s New Observationsmade with the aid of a telescope (~ 1610)
  • Discoveries useful in resolving the “geo-” versus “helio-” centric debate:
    • Venus exhibits phases like those of the Moon
    • The apparent size of Venus was related to the planet’s phase (as well as to the planet’s angular distance from the Sun)
    • Jupiter has four “Galilean satellites”; their orbital behavior is like a Copernican system in miniature
galileo s new observations made with the aid of a telescope 161023
Galileo’s New Observationsmade with the aid of a telescope (~ 1610)
  • First fundamentally new astronomical data in almost 2000 years!
  • Contradicted prevailing opinion (and religious belief) and strongly suggested a heliocentric (Copernican) structure of the “universe”
scientific utility of the copernican heliocentric model
Scientific utility of theCopernican Heliocentric Model
  • Can deduce the true “sidereal” (as opposed to readily measured “synodic”) orbital periods of each of the planets [see textbook BOX 4-1 and Table 4-1]
  • Can deduce the distance that each planet is from the Sun, relative to the Earth’s distance from the Sun (1 AU); [see textbook discussion associated with Table 4-2]