An idea for a racialist science-fiction short story

[David_Sims]

There's some relativity related physics that might make for a good science-fiction short story.

A spaceship full of hostile aliens circles a space station full of humans (the good guys). It is moving at a significant fraction of the speed of light.

The humans believe it is keeping its distance because the doppler shift in its light is neither blue- nor red-shifted.

However, they are wrong! Because of special relativity, a fast-moving spaceship can be spiraling in on the object it is going around, while keeping its signals without any net frequency shift as seen by an observer at the spiral's center.

The angle, θ, subtended at the alien spaceship, away from the human observer's line-of-sight, which the sneaky alien spaceship would need to follow depends on the fraction of the speed of light it is moving, relative to the human space station.

θ = arccos{ −c/v + √[(c/v)² − 1] }

or

v/c = −2 / (cos θ + sec θ)

For example, if the alien spaceship is moving, relative to the human space station, at v = 0.3c, then it will need to be moving in a direction that is

1.724942037 radians

around from the humans' line-of-sight, rather than π/2 radians, or 1.570796327 radians to that line-of-sight.

The humans must figure this out before the aliens come within firing range with their turbolasers, or else!

You might have one of the humans getting suspicious because the aliens put a bunch of sodium vapor lamps on the outside of their spaceship, making it Entirely Too Obvious that the net shift (doppler & special relativity) in frequency is zero.

How could a space station full of humans be so ignorant as to fall for this cheap trick? Well, you could make the space station commander a black guy who thinks he knows it all because he had a high school level introduction to physics when he was younger.

This puffed-up, self-important analog of Benjamin Sisko just won't listen to his white underlings who keep trying to educate him on relativity and alert him to the danger.