imo the distinction has little to do with the "hardness" of the science. Science fiction has a thesis about society, technology, and how it shapes and reflects

imo the distinction has little to do with the "hardness" of the science. Science fiction has a thesis about society, technology, and how it shapes and reflects us (see: the root at Frankenstein) Science fantasy is about the hero's journey These are not mutually exclusive things, but it does also explain the Star Trek/Star Wars divide some are commenting on here.