Nick Csakany writes back in March 2003:
Here’s another one for your list. If you’ve already covered this, then I didn’t see it on your site. Did you notice how, in too many sci-fi movies, when you see a galaxy in the background, you almost always see it spiraling around its center? Shouldn’t it appear still? Likewise, when you see planets, their rotation is visible even if the screen shot is not from the space vessel’s point of view, but from a presumably standstill point outside?
A specific example would be The Empire Strikes Back‘s final scene with Luke staring out the window at the galaxy.
Aside from the fact you wouldn’t see the galaxy as clearly as that, the rotation period of a galaxy is measured in hundreds of thousands of years. But then again, even the Great Red Spot on Jupiter is sped up in movies (e.g., Contact). The Great Red Spot takes 6 days to make one rotation. You don’t even see the hour hand of your watch moving and that only takes 12 hours to complete one circuit.