The Origin Evolution of the Universe Section 9

The Origin & Evolution of the Universe Section 9. 7

Stephen Hawking’s “The Universe”

Our Expanding Universe • Until the 1920 s astronomers thought that the Milky Way was the entire universe. • Einstein used equations to predict that the universe was expanding. • Hubble was able to identify other galaxies and was able to say that it appeared that they were all moving away from each other. (To learn more read pg. 394 – Red Shift, Dark Matter/Energy)

The Big Bang Theory • Cosmologists – people who study components, evolution and physics of the entire Universe. • They believe that all matter and energy in the Universe expanded from a point that was smaller than the period at the end of this sentence.

Big Bang Continued… • Estimated that it occurred approx. 13. 7 billion years ago • When the explosion happened everything was very hot, as it cooled energy turned to matter which over time turned to stars and planets.

The Formation of the Solar System • According to the Solar Nebula Theory the Solar System was formed approx. 5 billion years ago from a massive cloud of gas and dust (solar nebula). • The collapsing nebula started a spinning motion – this is why Earth orbits the Sun.

The Future… • The Universe will continue to expand, galaxies will be pulled apart leaving more cold, empty space.

In Summary…

Today’s Tasks • Pg. 397 # 2, 5, 6, 8, 10 • Prepare for tomorrow’s In-class Chapter 8 & 9 assignment (you’ll be allowed to use your notes, textbook but you will be working ALONE)