A concise guide to the levels of Science in popular science fiction:
Star Trek: This is science-fiction, but we want our science to at least sound plausible. Therefore, most of the time, our scientific explanations will be rooted in scientific fact or at the very least solid, generally accepted theory.
Stargate: We’re about half and half. We try to make it plausible sometimes, but usually you just have to technobabble your way through it.
Star Wars: This man has a laser sword. Why does he have a laser sword? Because laser swords are cool. This is all the explanation you need.