But what about tachyons (a highly unlikely particle favored by Star Trek writers), or gravity boots, or warp/hyper drive? These and thousands of other devices are sheer fantasy and can't be dressed up as 'coming to a reality near you' simply by giving them a funky name. A Plesnian Ion Field Emitter that creates a barrier between you and your enemy is no more plausible than a Twallzari Druidian Separation Spell. But for some reason, one works in genre A and the other in genre B.
This kind of gray area gives plenty of food for fandom to blog about. So let me throw a couple more photon on the fire. In Quantum SF, where our world connects to the world of quantum mechancis, how do we bridge that gap if not with some kind of fantasy? It borders on mysticism.
I have a friend who leans more towards mystic consciousness in his preferences to the uber quantum world whereas I tend towards the hard science. He postulates that if you can think it, it can exist. Standard enough “I think therefore I am” stuff, but he goes further to suggest that if a mystic monk can control his body environment (ie: keep healthy, cure internal disease, etc.) then why can’t he control the surrounding reality, too? Can we change reality through our deeper levels of consciousness? Would that change the equations? Would we know? This gets to the fundamental question of reality and there is a huge population that believes in mysticism, higher consciousness, etc. as firmly as physicists believe in dark matter. Neither can be proved imperically but it doesn't shake their belief.
After much reading on quantum physics I keep coming back to this question: Is quantum reality simply a metaphor for the equations? After all, why create 11 dimensions in String Theory unless they make the equation balance? Same with 3 branes, multiverses, and dark matter. Are these contrivances simply metaphoric descriptions of an equation for the layman to understand?
If we reverse the question to read: is the math simply our description of reality? Then, says my friend, couldn't there be other ways to describe reality, perhaps through consciousness and other metaphysical language? In truth, consciousness is our only way to understand or describe reality.
This is a complex topic and my brief example is only meant to spark the concept that using mysticism, conscious altered reality, and other metaphysical states impacts the SF vs. Fantasy puzzle. There is much literature based in mysticsm that isn't called science fiction.
Maybe it should be...