All this talk of the differences between sci-fi and fan-fi is kinda rediculous. To people(not me) who dont like either -think they are indistinguishable. They are twins in the family of fiction. Remeber Arthur C. Clarks (Celebrated Sci-Fi Author) 3 Laws :-
1)When a distinguished but elderly scientist states that something is possible, he is almost certainly right; when he states that something is impossible, he is probably wrong.
2)The only way of discovering the limits of the possible is to venture a little way past them into the impossible.
3)Any sufficiently advanced technology is indistinguishable from magic.Isaac Asimov Wrote collections of Sci-fi stories and called the series
Magic. Fallout has the same foundation as many Fantasy foundations. Take Terry Brooks Shannara series - its all based on events following the apocolypse on Earth. Sci-Fi
IS Fantasy. Plasma Guns used to be considered
MAGIC. Also just because you dont believe the evidence of the existence of ghosts, doesnt mean they dont. Many people still dont believe The theory of Man/Evolution. Creationists (i.e. Millions (if not Billions) of people still beieve in
THAT kind of Magic.
And Finally theres not much difference between Roddenberry's Vulcans and Tolkein's High Elves.