thelearningbrain:

So say you command a ship in Star Fleet and you shoot photon torpedoes in a battle and they don’t hit the other ship, aren’t they still governed by Newton’s laws of physics? Don’t they just keep beaming through space until they finally hit something and most likely destroy it? Why do we never hear about this kind of collateral damage?

The easy answer is that it’s called ‘space’ for a reason … It’s a very empty place, and the probability of randomly firing in any direction and hitting something is near zero, especially when ‘nearby’ is defined in distances measured in light years. http://science.howstuffworks.com/dictionary/astronomy-terms/question221.htm