12.5.2007 - astronomy

12.5.2007 - astronomy - surface of the sun. v = H d v = d/t...

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12.5.2007 – astronomy Cosmology The primary way we know about dark matter is gravitational influence Also, mass warps the path that light travels (Einstein) Expansion of the Universe: Hubble’s Law: The farther away a galaxy is, the more red-shifted it is. Universal recession Velocity at which a galaxy appears to be moving away = Hubble’s constant * distance v = H 0 d H 0 = 70 km / s / mpc No edge or center Olber’s paradox: If the universe is homogeneous, isotropic, and infinitely old, the night sky would be as bright as the
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Unformatted text preview: surface of the sun. v = H d v = d/t t = 1 / H = 13.8 0.7 gigayears Age = 13.7 0.2 giga years The Big Bang-> Are we at the center of the explosion? No. Hubbles law implies that there is no center to the explosion Expansion of the universe is accelerating. there must be some other force at work: Dark Energy Dark energy accounts for about 70% of the energy in the universe 30% is matter: 85% is dark matter, 15% normal matter...
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This note was uploaded on 09/24/2009 for the course ASTR 101 taught by Professor Christiansen during the Fall '08 term at UNC.

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