What is SF?
I've called myself a fan of "science fiction" or "sci-fi" for years. I'm going to change that. I'm going to start calling myself a fan of "speculative fiction" or "SF". Why? Norman Spinrad.
Spinrad writes "On Books", a monthly book review column for Asimov's. In the July 2014 issue of Asimov's, he discusse the difference between speculative fiction and fantasy.
[L]iterarily speaking, fantasy is any fiction based on an element of the impossible that both the reader and the writer believe is impossible, that being the literary game. But literarily speaking, science fiction must be fiction based on a speculative element that does not knowingly violate the current scientific concept of the laws of mass and energy; the improbable for sure, the highly improbable, why not, but not the forthrightly known impossible.
Does the speculative element have to be scientific or technological? Not really. Literarily speaking "science fiction" is really an accidental misnomer for "speculative fiction"—that is, fiction with a speculative element of the currently non-existent but possible.
We generally count Orwell's 1984 as speculative fiction, whose speculative element is political. Or Theodore Sturgeon's More Than Human, whose speculative element is psychological. Or Bradbury's Fahrenheit 451, whose speculative element is cultural. The speculative element doesn't have to be scientific or technological. But speculative fiction does have to be something set in the future, at least in the immediate future, not the past, and not in a knowingly impossible realm of fantasy.
For a speculative element must be currently non-existent but perceived as possible, something that could exist—in the future.
So speculative fiction by its very literary nature does have to be set in a future, however far or immanent that future may be. The change or changes it postulates cannot be known impossibilities, because if they are, the story is inherently fantasy.
That's what makes it speculative fiction.
There is much that is called "science fiction" that is not science based, that is not truly speculative, and that, by this definition, deserves to be called fantasy. Spinrad believes this is a problem because it confuses "science with magic, wishful thinking with real possibility". We should, instead, look forward "with a visionary eye, heart, and mind to multiplex possible futures that are not merely futures that we will make, for better or for worse, but that we cannot avoid making, one way or the other."
This encapsulates what I have always loved about SF. Good SF acts a little bit like a car's headlights. It partially illuminates what's coming next and either excites me or warns me. It can give me an advance glimpse of the good times that are coming or an advance warning of the dangers that lurk just out of sight.
I want to refocus on reading true speculative fiction and not just "science fiction". I still enjoy fantasy and I still plan to read plenty of it. But it's the true speculative fiction that gets me excited and that I want more of.