1. What is this? PH1600: Introductory Astronomy Lecture 23: Early Forces and Inflation

2. PH1600: Introductory Astronomy Lecture 21: Early Forces and Inflation Study: Chapter 19 in The Cosmos book Next Lecture: Chapter 20: Life in the Universe School: Michigan Technological University Professor: Robert Nemiroff Book: The Cosmos by Pasachoff & Filippenko Online Course WebCT pages: http://courses.mtu.edu/ This class can be taken online ONLY, class attendance is not required!

3. You are responsible for…  Reading the book One chapter per “quiz period” Anything from that chapter can appear on quizzes or tests, even if I never mention them during my lecture(s) This quiz period covers Chapters 18  APODs posted during the semester APOD review every week during lecture  Completing the Quizzes Chapter 1, 2, 4, 6, 7, 8, 10, 11, 13, 14, 15 & 18 quizzes already due Chapter 19 quiz due next See WebCT at http://courses.mtu.edu/ for detailshttp://courses.mtu.edu/

4. Inflating the Universe Credit: WMAP Science Team, NASA APOD: 2006 March 23

5. Forces in the Universe  Gravity  Electromagnetism  Strong Nuclear Force  Weak Nuclear Force  Electroweak force  Grand unified theories  Superstring theories

6. Different types of energy Dark Energies (gravitationally repulsive)  Phantom energy (hypothesized)  Cosmological constant  Domain Walls  Cosmic Strings

7. Different Types of Energy  Matter Dark matter, atoms,  Radiation Light, neutrinos, axions, etc.  Ultralight (?) Only hypothesized  Scalar fields

8. Problems with Original Big Bang  Horizon problem Why is the universe so uniform? How does the left part of the universe know to have the same temperature as the right part?  Flatness problem Why is the geometry of the universe so close to flat?  Magnetic monopole problem

9. Inflation to the Rescue  Universe suddenly begins to expand exponentially  Caused by phase transition as strong nuclear force freezes out  A repulsive “cosmological constant” temporarily dominates the energy density of the universe  As inflation ends, matter and radiation are (again?) created

10. http://www.greenspirit.org.uk/resources/inflation.JPG

11. http://abyss.uoregon.edu/~js/images/inflation.gif

12. Timeline for the Early Universe  t=10 -43 sec, T=10 33 K Planck scale: theory of everything  t=10 -37 sec, T=10 29 K Grand unified theory phase transition Strong nuclear force freezes out Inflation  T=10 -35 sec, T=10 28 K Inflation ends Particles created

13. Timeline for the Early Universe  t=10 -12 sec, T=10 16 K Weak nuclear force freezes out Particles acquire masses  t=10 -6 sec, T=10 13 K Quarks combine to form protons  t=10 -2 sec, T=10 10 K Neutrinos decouple from protons

14. Higher Dimensional Universes  Could our universe have more than three spatial dimensions?  Large far away dimensions Tension force holds us to 3D  Small rolled up dimensions? Small scales hide higher dimensions  http://dogfeathers.com/java/hyprcu be.html

15. http://pdg.lbl.gov/~phiggins/universeadventure/universe_stringtheory3.html

16. http://www.zeropoint.ca/7dimensions.jpg

17. Multiverse Hypotheses  Many other universes might exist  In space: causally disconnected  In space: occupying other dimensions  In time: Oscillatory universes Example: Bang, crunch, bang, crunch. Etc.

18. Multiverse Hypotheses  Many Worlds Interpretation Every possible outcome of every random event actually exists We occupy only one realization Zillions of “you” exist in other “parallel universes” Only conjecture  Might not even be testable

19. Multiverses: Do Other Universes Exist? Illustration Credit & Copyright: Clifford Pickover APOD: 2006 March 1

20. The Anthropic Principle  Only universes where we exist are allowed  Example: A quick Big Crunch universe that never developed life could not be our universe  Controversial when used Statistical occurrences hard to quantify

21. A Force from Empty Space: The Casimir Effect Credit & Copyright: Umar Mohideen (U. California at Riverside) APOD: 2002 September 17