Science fiction is really sociological studies of the future, things that the writer believes are going to happen by putting two and two together.
Ray BradburyYou don't have to worry about the future, you don't worry about the past - you just explode.
Ray BradburyScience fiction is any idea that occurs in the head and doesn't exist yet, but soon will, and will change everything for everybody, and nothing will ever be the same again. As soon as you have an idea that changes some small part of the world you are writing science fiction. It is always the art of the possible, never the impossible.
Ray Bradbury