premise: It has been suggested that SF include only those stories which would be invalidated without their scientific content ; that fiction which concerns science , scientists , and the impact of science on humans ; that which explores alternate existences ( whether future , extraterrestrial , or only in characters ' minds ) based on facts and logical progression via scientific method .
hypothesis: It has been suggested that SF include only those stories which would be invalidated without their scientific content ; that fiction which concerns science , scientists , and the impact of science on humans ; that which explores alternate nonexistence ( whether future , extraterrestrial , or only in characters ' minds ) based on facts and logical progression via scientific method .