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No End in Sight: The Runaway Expansion of the Universe and the Fate of the Cosmos

By Geoff Handsfield and Orville Day Dept. of Physics, East Carolina University 1 April 2008. No End in Sight: The Runaway Expansion of the Universe and the Fate of the Cosmos. Olber's Paradox, “The Dark Night Riddle”. Why is the sky dark at night? Consider the following:

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No End in Sight: The Runaway Expansion of the Universe and the Fate of the Cosmos

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  1. By Geoff Handsfield and Orville Day Dept. of Physics, East Carolina University 1 April 2008 No End in Sight: The Runaway Expansion of the Universe and the Fate of the Cosmos

  2. Olber's Paradox, “The Dark Night Riddle” Why is the sky dark at night? Consider the following: • Light radiation never terminates-- only spreads out • Trillions of stars in observable Universe. • 400 billion stars in Milky Way Galaxy. • All light eventually reaches Earth.

  3. Inside the Big Dipper

  4. Types of Galaxies • Spiral • Disks • Elliptical • Irregular

  5. Einstein & Relativity, Hubble & Expansion • Space-time is fabric, not void. • Mass creates dimples in fabric. • Galaxies expanding away. • Simplest explanation: space-time stretching.

  6. Big Bang

  7. Big Crunch? • Prevalent for 30 years in astronomy • Idea that Universe will collapse back to Big Bang • Relies on assumption that mass/gravitation will eventually overpower Universal expansion. • Proven false in 1998.

  8. The Supernova Cosmology Project Dr. Saul Perlmutter at UC, Berkeley • Measured Red Shifts of Type Ia Supernovae (White dwarfs in binary system absorb matter until reach Chandrasekhar Limit)

  9. Hypothesis 3 Scenarios • Expansion slowing, result in Big Crunch • Expansion slowing, result in equilibrium • Expansion speeding up, accelerating Univ.

  10. Results • Expansion increases in time. • Fate of the Universe-- cold death. • Confirmed by independent research conducted by rival team, High-Z Supernova Search Team. • Big Crunch unlikely.

  11. Cause of the Expansion- Dark Energy • Energy counterpart to dark matter. • Source of dark energy unknown. • Opposite force to gravitation. • Exhibits properties of negative pressure. • As Universe expands, more dark energy seeps into all space, providing more anti-gravity.

  12. Fate of the Universe • Observable Universe increases in time. • Objects in observable Universe decreasing. • Fewer interactions with celestial bodies. • Ultimate destruction by black holes at center of galaxies. • Black holes ultimately evaporate by Hawking radiation. • Universe a lonely place-- average density drops toward zero. Only stray particles remain.

  13. Olber's Revisited • Finite Age of Universe • Finite Speed of Light • Accelerated Expansion of Universe • Stretching of Space-Time

  14. Sources • Bennett, Donohue, Schneider, Voit. The Cosmic Perspective. • Goldsmith. The Runaway Universe. • Harrison. Cosmology. • http://www.nasa.gov/images/content/152808main_RSoph_full.jpg • http://www-news.uchicago.edu/releases/03/darkmatter0903.jpg • http://www.theonlinecandyshop.com/ProductImages/CRUNCH.jpg • http://preposterousuniverse.com/spacetimeandgeometry/covercrop.jpg • http://z.about.com/d/physics/1/0/r/-/-/-/BlackHole.jpg

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