Galaxies and Cosmology /

Types of Galaxies Spiral –Including Barred Spiral Elliptical Irregular

M81 12 million light years away

M82 12 million light years away

NGC million light years away, 85,000 light years across

NGC million light years away

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

Big Bang

Hubble Ultra Deep Field 10,000 galaxies, up to 13 billion light years away

Close up of HUDF

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 1989 George Smoot and John Mather awarded Nobel Prize in 2006

WMAP launched 2001

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