Random observations that I've garnered from reading and watching science fiction:
- When in doubt, blame that tachyon cloud.
- In order to generate gravity on a ship, it has to rotate, and the further you are from the core of the ship, the less the gravity will be. For some reason, parks will be located on the inside of the outer walls of huge spaceships, but the dirt and plants will never float off.
- If you want to get around that pesky speed of light limitation when traveling in space, add an "imaginary number" to your calculations like Catherine Asaro does in her Skolian books.
- If you're many thousands of kilometers away from your enemy and they've fired off their full load of whatever type of laser/xray/whatever torpedoes they have, bend over and kiss your @ss goodbye. One of the best scenes regarding this was in one of David Weber's Honor Harrington books, when all they could do was wait for what was launched at them to hit them, and vice versa.
- Moons are in the sky to look pretty. They don't affect the environment on the planet
- Cockroaches and rats haven't figured out how to get onto space ships, unless they are full-sized representatives of an alien species.
- Interstellar communication is either instantaneous or else takes months. There is no happy medium.
- Forget about fancy-shmancy weapons - just bombard a planet with meteors.
- Most writers forget that air is a commodity in space, just like water or food.
- Universal translators make your lips move the proper way for the language you're supposed to be speaking
- Everyone understands and can read any alien alphabet - unless it's an ancient one, then they are totally baffled.
- Children on a spaceship should be neither seen nor heard. Unless it's a generational ship, they have no business being on a military vessel.
- No matter how far away or how alien a spaceport is, clamps, docking rings and utility hookups are universal.
- Earth colonies, even if they are millions of miles away and hundreds or thousands of years in the future, still use today's common names and surnames.
- Spaceports, for some reason, have lower levels that have been forgotten by the authorities or are in disuse for some reason, and disreputable people can live there unobserved and free of charge.
- No terrorist ever seems to think of taking out "space elevators".
- The command bridge is always in the most vulnerable spot; the battle bridge is always in the most protected spot on the ship; yet the battle bridge is always the one that is taken out first.
- If two crew members are planning to get married, one of them will die suddenly and tragically.
- No one ever inadvertently trips over a maintenance robot.
- Anything can be fixed if you can access the Jeffries tube.
- Sonic showers somehow clean you thoroughly without ever causing any long-term aural damage.
- There's always some idiot who wants to rule the world/planet/system/universe.