1. NOTES: The Solar System: Origin: the nebular theory fits most of the facts. The nebular theory: 1. The Big Bang produced lumpy clouds--COBE satellite. 2. Recycled star stuff with heavier elements combined with H and He gas from Big Bang, and gravity pulled it together. There were two supernova in our region. 3. The gas cloud collapsed to a spinning disk and a globe in the center. 4. It heated as it collapsed, the center hotter than outer regions: Helmholtz contraction or heating. 5. The sun's magnetic field slowed its rotation by dragging on electrons. 6. There were swirls formed to predate satellite systems. 7. The inner regions were too hot to allow light gases to collect. This left heavier elements and produced terrestrial planets. 8.The outer regions were cool enough to allow large amounts of H and He to collect into the Jovian Planets. 9.Dust collected into planetesimals, planetesimals into protoplanets. Gravity smoothed the larger objects to spheres. 10. All planets, the sun, and satellites rotated and revolved in the same direction (prograde). Some planets (Venus, Uranus and Pluto) rotate retrograde because of large collisions (Velikovsky).

2. Steps in how the solar nebula forms.

3. The Nebular Hypothesis

4. Conservation of Angular Momentum: Contraction  increase in rotation, shown in reverse above.

5. Hannes Alfven explained why the sun seemed to rotate slower than conservation of angular momentum would suggest

6. If you spin underwater with your arms out, it slows you down. The magnetic field in the solar nebula disk is like the arms, the charged particles in that disk are like the water.

7. The Solar Nebula heated as it collapsed, the center hotter than outer regions: Helmholtz contraction or heating. Compressing a gas makes it hotter, as particles move faster.

8. Gravitational potential energy between dust particles and gas becomes kinetic energy of motion or heat.

9. The inner regions were too hot to allow light gases to collect. This left heavier elements and produced terrestrial planets.

10. Planetesimals (rocks) formed out of the dust by gravity.

11. Planetesimals condensed into planets, moons, and asteroids.

12. Protoplanet model by Pawel Artymowicz of Sweden

13. Prograde vs Retrograde Rotation: Only Venus, Uranus spin retrograde --opposite to earth.

14. Velikovsky in 1950’s suggested Venus was hit by something big, flipping her rotation. He was labeled a ‘crackpot’.

16. Radar Ranging: bounce radio waves off planetary body. Distance = speed of light x time