nah, fantasy and sci fi are all based on existing things
I guarantee you that Star Trek's warp drive is based on nothing that exists now or ever could be.
No, but it is a concept that can be constructed in reality through inference of existing motions. "Warp drive" probably wasn't conceived by many people during the Stone Age. But during the era of rapidly expanding technology, these ideas could be grasped more readily.
What about Leonardo Da Vinci creating the plans for flying machines and cars?
Noticed I said not by "many people" in my reference point. Da Vinci, like many throughout history, was a highly intellectual and creative man during his waking life. He also was surrounded by technologies of his era. That's not to say every citizen back then could realistically envision these things like we can now. Everyone understands these concepts now, of course.
Dude nothing you are saying makes any amount of logical sense. Davinci dreaming up stuff he had no possible way have a concept of doesn't count because reasons... ---