1 / 47

Some imagination required!

Some imagination required!. When I Heard the Learn'd Astronomer by Walt Whitman. When I heard the learn'd astronomer, When the proofs, the figures, were ranged in columns before me, When I was shown the charts and diagrams, to add, divide, and measure them,

katoka
Download Presentation

Some imagination required!

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. Some imagination required!

  2. When I Heard the Learn'd Astronomerby Walt Whitman When I heard the learn'd astronomer, When the proofs, the figures, were ranged in columns before me, When I was shown the charts and diagrams, to add, divide, and measure them, When I sitting heard the astronomer where he lectured with much applause in the lecture-room, How soon unaccountable I became tired and sick, Till rising and gliding out I wander'd off by myself, In the mystical moist night-air, and from time to time, Look'd up in perfect silence at the stars.

  3. Alternate models • geocentric • heliocentric Which model is “true”?

  4. demo

  5. Diurnal motion • Daily motion of all the objects in the sky

  6. Motion of the Earth • Rotation about axis once every 23h56m (sidereal day) • Revolution about sun once every 365.25 days • Precession of axis every 26,000 yr • All are counterclockwise (seen looking down from North Pole)

  7. Precession Takes 26,000 years

  8. What causes seasons? • Northern and Southern hemispheres have opposite seasons • Earth closest to sun in January • Varying distance of sun only changes intensity of light coming to earth by a few percent

  9. Summer Solstice • Sun highest in sky • shortest shadows • Longest day • Most direct sunlight • warmest • Sun is at the northernmost point of the ecliptic Winter Solstice just the opposite!

  10. Equinoxes • Vernal (spring) and autumnal (fall) • Equal hours of daylight & darkness • True everywhere on Earth! • Sun is at the point where ecliptic crosses celestial equator • Length of day changing fastest

  11. analema

  12. Waxing crescent What phase is the moon in today?

  13. animation

  14. Eclipses • Caused by shadows of earth & moon • Don’t occur every month because of 5° inclination of moon’s orbit

  15. Web sites Astronomy Picture of the Day http://antwrp.gsfc.nasa.gov/apod/astropix.html Comins & Kaufmann (textbook) http://whfreeman.com/dtu6e others space.com astronomydaily.com skyandtelescope.com

More Related