Acclaimed science fiction author and literature professor John Kessel recently gave a fantastic talk about science fiction, and you can watch the whole thing online. Here's the blurb:
Science fiction is popularly understood to be about showing us the world of the future: space travel, robots, immortality, encounters with aliens, mechanized cities, human evolution. But in fact much science fiction, though it may be set a hundred or a thousand years from now, is more about the present than about times to come. Both consciously and unconsciously, the futures science fiction writers present arise from and comment on the way things are today, often with the goal of changing the present or even preventing the future.
This talk shows how this has been true from science fiction's earliest days until now. It gives examples from books and films of ways in which sf had held up a fun-house mirror to the present, both serious and comic, restricting and liberating.