The Star Trek Communicator became the Nokia RAZR, yet people still mock sci-fi for being too “out there.” What makes us uncomfortable in fiction soon becomes a necessary crutch in real life. I found out yesterday that a friend of mine is having his knees replaced. I wasn’t surprised, just asked how long the re-hab would be. “A few weeks,” he said. “Then they’ll last ten to twelve years before they need to be replaced.” Like rubber tires. Which must have seemed just as unusual to buggy aficionados. Which probably…