I hope everyone here understands comic book physics.
Comic book physics is what allows Kid Miracleman to lift a tanker truck full of petrol and smash it down on top of Miracleman's head. You see, real physics doesn't allow that. Real physics states that the truck would crumple and the part that Kid Miracleman is grabbing would come off of the truck. But in comic book physics, a super strong hero can lift an aircraft carrier with one hand, as if the entire weight of the aircraft carrier could be supported by the tiny portion of it's structure touching the superhero's hand. In comic book physics, things don't break unless the hero is a newbie and it would be funny for it to happen.
(Real physics sucks. I can't even lift my car to change the tire if I put the tire jack in the wrong place.)
By the same token, there are certain laws of physics that sci-fi regularly gets wrong, mostly intentionally, and I think it would be fun to start a thread about them. Site examples if it would make your post funnier.
I'll start by raiding Atomic Rockets.
1) Down is a legitimate direction in space. Space ship decks can be laid out perpendicular to the direction the ship regularly accelerates in, so that the engines are at your back, the bow is at your front, and your feet point... down, because well... down exists in space. In fact, all ships share the same down direction even if they all have their own artificial gravity generators. You never see any ship aligned so that her artificial gravity plating points off to the upper right.
2) Space is filled with "stuff". This "stuff" pushes against your spaceship, so that if you shut off the engines, your ship would stop. This is why gunstars, and the Millennium Falcon and what not have to have their engines on the entire time they're going anywhere. This "stuff" is what vibrates, carrying sound, so that the heroes can hear when enemy ships explode. This is why space fighters that have wings are more maneuverable. The wings push against the "stuff" and help the craft maneuver. This "stuff" is also what keeps ships traveling along the line that it's nose is pointing. Without this "stuff" the ship would go off to infinity, in the direction of it's last vector, no matter which way it's nose was pointing. The fact that ships have to push this "stuff" out of the way is also why small fighters are more maneuverable than large carrier ships. Also your ship's engines push against this "stuff". Without that "stuff" there, if an enemy ship ever "got on your tail", the reaction mass being pushed out of the back of your ship would shred it to pieces or burn it to a cinder.
This "stuff" however, will not protect you from explosive decompression. If you go outside without a space suit, you will explode.
3)Unless it has an engine, no object in space is ever going anywhere. Asteroids, planets, stars, these things are always stationary in regards to each other. Asteroids might hit each other, because of course asteroid belts are really crowded, but the asteroids never leave the asteroid belt. Comets move, but they are always far away so that doesn't matter. Space stations never need station keeping, so they have no engines. It's always easier to break pieces off of an asteroid and carry them away with you than it is to move the whole asteroid to somewhere where its materials can be put to use.
4) Did I mention that asteroid belts are really crowded? Well they are. You would be crazy to fly through there!
5) Things in space aren't really that far away. If it takes you 2 weeks to fly to Jupiter, your ship has kind of weak engines. They would not at all be more powerful that the United States of America's entire nuclear arsenal.