Bad Astronomy: Misconceptions and Misuses Revealed, from ...

BAD ASTRONOMY GOES HOLLYWOOD 253
Trek would sometimes have the Enterprise lurch as it approached
a planet and gotten “stuck” in the gravity, sending hapless crewmembers
flying from their stations. Luckily, the universe doesn’t
behave that way.
You’d think after the second or third time that happened,
someone down in the Enterprise’s engineering section would have
whipped up some seat belts.
8. As stars flash by . . .
When you’re talking real estate in outer space, it’s not location,
location, location but scale, scale, scale. Planets are pretty far
apart, but stars are really, really, really far apart. The nearest star
to the Earth (besides the Sun) is about 40 trillion kilometers (25
trillion miles) away. Even distant Pluto is 8,000 times closer than
that. You can go all the way across our solar system and, to the
naked eye, the stars will not have appeared to move at all. The
constellations will look the same on any planet in the solar system.
But actually, if you go to Pluto, for instance, the stars will
appear to move a tiny but measurable amount. The European
satellite Hipparcos was launched specifically to measure the change
in the apparent position of stars as it orbits the Earth. By making
exact position measurements, you can determine the distance to
nearby stars. Hipparcos has already revolutionized our ideas on
the size of the universe simply by finding that some stars are about
10 percent farther away than previously thought. The downside of
this, of course, is that the commute for the aliens is longer.
I was once fooled by someone asking what was the nearest star
to the Earth. “Proxima Centauri!” I piped up, but of course the
real answer is the Sun. In the movie, Star Trek IV: The Voyage
Home, the Enterprise and crew need to warp past the Sun to go
back in time. There are two problems with this scene. One is that
you can actually see stars moving past them as they travel to the
Sun; there aren’t any. Second, at the speed of light, the Sun is
a mere 8 minutes away. At warp 9 they would have zipped past
the Sun in less than a second. That would have made for a short
scene.