Your Orientation... In Space

Recently, Glenn and I have been watching a bunch of things showing on the SciFi channel, and it made me think back to watching Firefly/Serenity earlier last semester, and a few other shows and movies I've watched that take place in space.

A big thing I've noticed is that in each of these fictional universes, there seems to be an absolute standard as to what's "up" and what's "down." You never see two spaceships flying around, with different orientations.

Another tidbit, one that's almost contrary to the first "rule" of space, is that you and your spaceship are always "above" whatever planet you're closest to, as though all planets are sitting down on one 2-dimensional plane, and you can always fly above them.

Just some weird observations, there are probably more weird things like that about science fiction, this just happens to be the one I noticed most recently.