Vive la Différence: Science Fiction and Fantasy

Vive la Différence is a new feature of the blog (probably, note previous posts) where I take a couple things that have been (sometimes inexplicably) intertwined with one another and talk about what, to me, are the core differences between them.
Today's two sacred cows ready to be slaughtered, ground, and grilled are the venerable statesmen of nerdery...science fiction and fantasy.
Even undergradutes in Nerdery or Geekonomy are aware of Clarke's law that any sufficiently advanced technology is indistinguishable from magic. This more than anything save the overlap in fandoms explains why these two genres have been so closely linked. While the early days of "hard science fiction" tried (and typically succeeded) in grounding their worldbuilding in hard science facts, this eventually fell by the wayside for the most part.
Eventually you get into the areas of Space Opera, such as Flash Gordon, Buck Rogers, or the Star Wars franchise, that don't even try and hide the fact that they are essentially fantasy stories with the trappings of science fiction.
"But how does it work?" the fan says. "It's futuristic, advanced technology!" the author might reply, "so it just does." And, for the most part, this has been perfectly acceptable. Although, every now and then you'll find a series of sci fi novels that tries to pay more than the usual amount of lip service to science fact. The Honor Harrington series comes immediately to mind.
Nevertheless, there is still a moment where we, the reader or viewer, have to suspend our disbelief and just accept that the tech works because the fictional people have discovered some esoteric fact or formula that we have yet to stumble upon.
Which sounds dreadfully like magic if you think very hard about it. Is there a great distance between the scientific laboratory with its bubbling beakers and Jacob's Ladders and the alchemist's workspace with its bubbling beakers and stuffed alligators? Is there a great distance between the scientist's unintelligible scribblings on a blackboard and the draconian scratching of ancient glyphs on the diabolist's floor?
I have come to the conclusion that the main difference between science fiction and fantasy is one of attitude. Generally and broadly, in a science fiction story, when something inexplicable happens, there's someone there to insist that there is an explanation. In fantasy, at some level, it is entirely appropriate and accepted to shrug your shoulders and figure faeries did it.
This isn't to say that there aren't rules for magic. John Butcher's Dresden Files exemplify the marriage of vague science fact with eldritch fiction. The energy for spells has to come from somewhere, there are sympathetic energies, etc. But at the same time, there are beings ancient and terrible who are what they are because they are beings of magic and nobody is even considering subjecting them to the scientific method.
And this isn't a bad thing! The supernatural fills us with a cold, quiet dread that defies our modern understanding of the world. That's it's job.
The flipside of this, for me, is the JJ Abrams created television show Fringe. I realized that all the wild happenings that kick off each individual episode (including some Big Picture elements I won't discuss due to their spoileriness) could easily be described as spells, precognition, or simply magic. But every time Walter shows up on the scene, everybody turns to him and say, "Whaddya think, Walter?"
And even if Walter doesn't immediately know, his attitude is always that he can figure it out. "But I can't know for sure until I get back to my lab." He should just have a sign. Or I should have a drinking game. Or both.
Now, some wily magus in a fantasy story might act the same way. And there is certainly a point of suspension of disbelief for both types of story. But the attitude is certainly more at home in one type of story than the other.
As a writer, this was a big discovery for me. Did I want to dwell on the details of the weird happenings? Did I want them to be explainable? Did I want my intrepid heroes to stare into the eye of the unknown and overcome their fear to deal with it? Or did I want them to hitch up their lab coats and insist it make an accounting of itself?
Thinking about the tone and feel of the story I'm planning helped me decide if it would work better as sci fi, fantasy, or some mash up. But if it is a mash up, I still know which style I wanted to emphasize. I mean, in a 50-50 situation, everybody still angles for the hyphen, right?
So vive la différence, science fiction and fantasy! We love you for different reasons, but we may not love you deeply until we know those reasons!