(so far, this is a work-in-progress. Keep checking back. Hopefully it'll be in fairly final form by the time we begin class)
* Science is the art of asking Nature herself how she works. The steps: Observe, make hypothesis, find logical observable implications, and search for evidence these implications are in the real world.
* Occam's Razor - simpler explanations have a better chance of being true. Carl Sagan's corollary - extraordinary claims require extraordinary evidence.
* Gravity pulls stronger between objects when they're closer, or more massive.
* Gravity pulls on the near side stronger than the far side, so object is stretched - the "tidal force". The bigger the object, the more tidal stretching it will feel.
* Light has energy, but no mass. Travelling oscillating force fields which deliver energy when you "see". Shorter wavelength = higher energy.
* For an isolated system, the total angular momentum cannot change; it can shift around, but not change. Examples of approximately isolated systems: planets and their moons, binary stars, individual galaxies far from other galaxies.
* More massive objects cool slower. Example: more massive planets hold more of their original heat, and so have thinner crusts. Original heat is mostly due to impacts as the "solar nebula" material fell onto growing planets.
* Planetary atmospheres: At a given temperature, lighter elements (hydrogen and helium especially) move faster and escape the gravity into space more easily: Only the cold outer planets were able to retain hydrogen and helium. Since H and He comprise the vast majority of the original material, means the outer planets are much more massive than the inner planets.