One use of the term refers to a genre of writing, generally based on the concept of taking the current world and projecting into the future with some added "scientific" rules.
Another use of the term refers to a disbelief on the part of the user that something is going to occur - Cloning of humans is just science fiction.
23jan03 jcw - Might I suggest that we try to restrict ourselves to more or less Tcl-specific pages on this wiki? There's a "wikipedia" [L1 ] for such issues, and there are dictionaries [L2 ] and open directories [L3 ] which can do a far better job for general content...