2. Warm-Up 1.Convert 5.4 lightyears into miles 1ly = 6.10 12 mi 2.How will a star the size of sun die? Give me the steps in the process. Times Up!

3. Goal To analyze the various theories for how the universe will end and determine which seems the most well supported by evidence.

4. Fate of the Universe

5. Age of the Universe Rocks on Earth – 4.2 billion years Oldest stars – 10-12 billion years Universe must be older – Estimate backwards – 13.8 billion years http://www.universeadventure.org/big_bang/conseq-ageofuniv.htm http://scienceblogs.com/startswithabang/2009/07/31/the-size-of-the-universe-a-har/

6. The Theories There are 3 major theories for how the universe will end. – The Big Crunch – The Big Chill – The Big Rip

7. The Big Crunch + Dark Matter There is enough matter in the universe to slow its expansion – gravity takes over. Gravity will then pull everything back together into one single point again. Without dark matter, this theory is not possible. Dark matter http://sandeepdmisra.wordpress.com/2011/04/

8. The Big Chill Assumes that there is not enough matter to stop the universes expansion (gravity isn’t strong enough) The galaxies will continue to drift apart (moving more and more slowly) the stars will use up all of the universes hydrogen (can’t form new stars) Universe will become cold and dark.

9. Dark Energy In the 1990’s scientists “discovered” a new force in the universe: Dark Energy. Dark energy is the opposite of gravity. – Gravity pulls things together and dark energy pulls things apart. If the Big Crunch or Big Chill are correct we should see the expansion of the universe slowing… but it appears to be speeding up…

10. The Big Rip As the universe becomes more spread out dark energy has more power. This theory states that the universe will expand at a faster and faster rate dark energy will overpower gravity universe will be pulled apart (even atoms will be pulled to pieces) Runaway Universe (Start at 3:30ish) Runaway Universe

11. Likelihood The Big Crunch (Depends on what Dark Matter does) The Big Chill (Not super likely at this point) The Big Rip (Depends on what Dark Energy does)

12. Dark Matter/Dark Energy