Thursday, October 13, 2005


I'm in the middle of the astronomy class I teach for the local community college right now. This is the lab, so they are all deeply involved with it, except for occasional questions. Overall, they're doing pretty well, but based on the assessment I've done in class, they need more work with Kepler's Laws of Planetary Motion -- so I'm giving them a lab on just that.

If you want to write science fiction, you really need at least a basic understanding of astronomy. Too many times I've seen mentioned flights from one planet to another (or from the surface to a moon or space station or whatever) where the ship burns its engines to the halfway point, turns around, and then burns its engines the rest of the way to accelerate. Not just no, but heck no! Nothing moves in a straight line in outer space, in spite of what you may have heard. You are always in orbit around something, be it a planet, a star, or the galactic center. That means that you are always moving on a curved path. The more energy you burn, the closer you can get to that straight line, but it takes an infinite amount of energy to actually get a straight line. Kepler's first law says, "The planets (and everything else) move in an elliptical orbit with the Sun at one focus." You'll never be able to get that mythical straight line.

Taking an introductory astronomy class can keep you from making howlers like this one. There are a lot of misconceptions about astronomy that even educated adults carry around with them. For example, can you explain why we have seasons? I'll give you a hint, it has nothing to do with distance from the Sun (including whether one hemisphere is closer to the Sun than the other because of Earth's axial tilt). I'll leave that as an exercise for you; if you really can't figure it out, post a comment and I'll explain it.

Take a class! Astronomy, like any science, is a lot of work, but it can be a lot of fun, too! No matter what your level of science understanding is, taking a basic class will go a long way towards improving your science fiction writing.

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