Transcript Galaxy Galaxy + Galaxy + … Local group + Local

RESOURCES & ENVIRONMENT
CH. 1. PLANET EARTH
1-1. ORIGIN OF THE
UNIVERSE
Universe?
Star + Planets + Satellites + Comets + (Asteroids) +
Meteorites + Dusts + Gases . . .
 Star system
Star system + Star system + …  Galaxy
Galaxy + Galaxy + …  Local group + Local group + …
Universe
http://en.wikipedia.org/wiki/File:ESO-VLT-Laser-phot-33a-07.jpg
Image of the night sky above Paranal on 21 July 2007, taken by ESO astronomer Yuri Beletsky. A wide band of stars
and dust clouds, spanning more than 100 degrees on the sky, is seen. This is the Milky Way, the Galaxy we belong to.
At the centre of the image, two bright objects are visible. The brightest is the planet Jupiter, while the other is the star
Antares. Three of the four 8.2-m telescopes forming ESO's VLT are seen, with a laser beaming out from Yepun, Unit
Telescope number 4. The laser points directly at the Galactic Centre. Also visible are three of the 1.8-m Auxiliary
Telescopes used for interferometry. They show small light beams which are diodes located on the domes. The
exposure time is 5 minutes and because the tracking was made on the stars, the telescopes are slightly blurred.
The Universe within 50000 Light Years The Milky Way Galaxy.
http://www.atlasoftheuniverse.com/galaxy.html
More detailed map around Sun. # of stars within 5,000 ly = 600 million
Alpha Centauri, the closest star to us (4.37 LY (light year) away: 1
LY = 1013 km)
http://heasarc.gsfc.nasa.gov/docs/cosmic/nearest_star_info.html.
Andromeda, the closest galaxy to us (2.5 MLY away)
http://www.definity-systems.net/~apw/astro/galaxies.html
Galaxies around us. The ‘local group’.
http://www.definity-systems.net/~apw/astro/galaxies.html.
Theories of the Origin of the Universe
• Stationary Cosmology: A. Einstein
• Expanding Universe Theory
• Steady State Cosmology: F. Hoyle, H. Bondi, T. Gold
• Big-Bang Theory: G. Gamov
Evidences
• RED SHIFT: E. Hubble
• CMBR (COSMIC MICROWAVE BACKGROUND RADIATION):
A.A. Penzias, R. Wilson
http://en.wikipedia.org/wiki/File:Redshift.png
Absorption lines in the optical spectrum of a supercluster of distant galaxies
(BAS11) (right), as compared to those in the optical spectrum of the Sun (left).
Arrows indicating Redshift.
http://map.gsfc.nasa.gov/universe/bb_tests_cmb.html
http://www.jpl.nasa.gov/spaceimages/wallpaper.php?id=PIA16876