Nothing original was ever built or invented unless someone imagined it first. But in the extremely practical world of construction, almost everything we set out to imagine and build is based on what is currently doable. Almost all cutting-edge industry innovations are built on the last string of innovations that proved out and paid off.
Science fiction, however, earns its special place by opening a gap between what we can do today and what we might do tomorrow. It bridges that gap with a magical span that requires no buttressing and no load calculations, only conceivability.