3. Our Galaxy  Write you address:  16825 Spring Cypress Road  Cypress TX, 77429  United States of America  Earth, Solar System  2/3 Orion-Cygnus Arm  Milky Way, Local Group  Virgo Super Cluster  Universe

4. How old is the Milky Way?  Approximately 13.2 Billion years old  Easily seen in Rural areas when the Moon is below the horizon.

5. Where are you from?

6. Religion teaches men how to go to heaven, not how the heavens go. ~Galileo Galilee 1630

7. Steady State Theory

8.  Universe appears the same throughout all of time.  No end or beginning.  New matter is created to fill in the voids created by expansion.

9. Pulsating Theory

10.  Universe oscillates between expanding and contracting.  Big bangs and big crunches occur repeatedly with this model.

11. Big Bang Theory

13.  Georges Lemaitre (1894- 1966)  Catholic priest in Vatican Observatory  Independently derived Friedman’s equation (that describes the universe) and used Einstein's work to show the universe expanded from a single point with primeval atoms in 1927.

14. Evidence: Olber’s Paradox

15.  Heinrich E. M. Olbers 1758-1840  1826: States that the darkness of the night sky conflicts with the supposition of an infinite and eternal static universe.

16. Evidence: Hubble’s Law  In 1929, Edwin Hubble described how galaxies are receding in every direction at velocities proportional to their distance from Earth and each other.  In other words: The universe is expanding

17. Hubble’s law: Doppler effectDoppler effect

18. Evidence: Hubble’s law

20. Evidence: Hubble’s Law  Using distance and velocity measurements, we can cacluate how old the universe is.  T= d/v 4.4x10 17 seconds Calculate how old the universe is!

21. Evidence: Hubble’s Law 4.14x10 17 seconds = approximately 14.6 Billion years

22. Evidence: Nucleosynthesis  Creation of new atomic nuclei from pre existing protons and neutrons

24. Evidence: CMBR  Cosmic Microwave Background Radiation  Thermal radiation filling the observable universe almost uniformly.  Detected with sensitive radio telescopes.  Discovered in 1964 by American radio astronomers Arno Penzias and Robert Wilson.