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Galaxies and Cosmology. 09.27.07 / 09.28.07. Types of Galaxies. Spiral Including Barred Spiral Elliptical Irregular. M81 12 million light years away. M82 12 million light years away. NGC1300 46 million light years away, 85,000 light years across. NGC 1316 80 million light years away.
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Galaxies and Cosmology 09.27.07 / 09.28.07
Types of Galaxies • Spiral • Including Barred Spiral • Elliptical • Irregular
NGC130046 million light years away, 85,000 light years across
Edwin Hubble • In 1929, discovered most galaxies have a “red shift” • Like the Doppler effect when a car drives past • Expanding universe seemed only plausible explanation
Red or blue shift? • Most of the universe has a red shift • The Andromeda galaxy has a blue shift • Spiral galaxies show a slight blue shift on the side spinning toward us and a red shift on the side spinning away
Hubble Ultra Deep Field10,000 galaxies, up to 13 billion light years away
HUDF and baby galaxies- evidence for big bang- evidence that galaxies form by combining
Relativity • Einstein’s theory of relativity indicated an expanding or contracting universe • He believed in the steady state theory • So, he created the cosmological constant • Edwin Hubble’s discovery of red shift cause Einstein to retract his constant • He called the constant his greatest mistake
Distribution of elements • In 1948, George Gamow used the big bang theory to predict the distribution of elements in the universe • Measurements have since shown he was essentially accurate
Penzias and Wilson • Drs. Penzias and Wilson accidentally discovered cosmic microwave background radiation in 1965 • Awarded Nobel Prize for Physics in 1978 • The radiation was predicted in 1948 by George Gamow
Cosmic Background Explorer (COBE)launched in 1989George Smoot and John Mather awarded Nobel Prize in 2006
The universe is flat? • A flat universe has no center and no end • Parallel lines stay parallel and never return • Tested many times and confirmed by WMAP using variations in CBR See: “WMAP Cosmology 101: Shape pf the Universe” at http://map.gsfc.nasa.gov/m_uni/uni_101shape.html