I really hate it when people use the argument "It's science fiction, therefore it's not supposed to have real science." That's a completely nonsensical, wrong, and ignorant argument. "Science fiction" does not mean "Stories where all the science is made-up nonsense." It means fiction that is predicated on speculative advances in science or technology. Yes, there is science fiction in which the speculative science is fanciful, but there is also an extensive and successful category of science fiction in which the science is as solid and rigorous as the author can make it. "Hard" science fiction has been around since the time of Jules Verne, and authors such as Arthur C. Clarke, Hal Clement, Gregory Benford, Robert L. Forward, Charles Sheffield, and the like have built their careers upon it quite successfully. Many SF writers, including most of those I just mentioned, are working scientists and their fiction reflects their actual research. Often, hard SF inspires actual scientific research and discoveries. There's a long-standing symbiosis between science and science fiction, as they mutually inspire one another. There is plenty of real, solid science in the science fiction genre, even if it's very rarely represented on film or television. The characters and the events are fictional, and yes, a lot of the science is conjectural, but often it's very solidly rooted in known fact and theory.
So please, don't stress the word "fiction" in science fiction as if that somehow "proves" that it's all supposed to be gibberish. Don't paint the entire genre with that single broad brush. There have always been many science fiction writers -- including myself -- who care about getting the science right. It's just that very, very few of them work in TV or film. Something like Lost or Fringe represents, well, the more fanciful fringe of the genre, often closer to fantasy than SF. They are not exemplars of what science fiction is or what the label means.