I'm onto a sci-fi-ish story. It kind of keeps on revolving around 'life and after life' theme. It involves dimenson travel too. How far does one need to be correct with the facts/concepts involved in the sci-fi story? Can I make up new concepts which donot actually exist (ofcourse, i intend to explain them at depth too)? Or, to put it in other words: Do you ever read a sci-fi story and laugh the plot out saying, "haha! This is impossible. This guy is simply making up random crap!!"