Psst - Ix-nay on the ATAL-Fay in the layground-Pay.
And science fiction is the middle ground - starting within the laws of physics, and then diverging to either a small or large degree depending on the subject matter at hand.
Psionics, on the other hand, doesn't do this; they handwave away most effects with "ectoplasm" which might as well be "mana" for all the scientific implication it has.