As I grumble my way through a stack of recent science-fiction novels, I take heart from an essay written by Gary Westfahl that’s up on the Locus website. He analyzes with considerable clarity why the predictions made about the future by so many SF writers are so wildly wrong.
He lists seven fallacies that writers trip over — the fallacy of universal wealth, the fallacy of extrapolation, the fallacy of analogy, and so on. If you’re interested in writing SF, this essay is well worth reading. If, on the other hand, you’re a fan, and want to enjoy SF without letting your pesky old intellect get in the way, I’d suggest you avoid it.