Science fiction defies categorization since it includes a massive gathering of disparate kinds of fiction such as terror, futuristic, magical, dream along with a profusion of much more demonic monsters compared to the Middle Ages ever envisioned in its preoccupation with hellfire and damnation.
Interest, in the long run, is always partially fear-based-the unknown, the mysterious and 'what is-to-come'. H.G. Wells was profoundly worried about the threat/promise of technologies. You may read new science fiction books to know lots of science-related fictions.
He fought in his time to make a peaceful world community, deeply disappointed in his passing with humankind's inability to surpass the constraints of its time.
At the start of the cold war Ray Bradbury, a consummate romanticist, who composed the amazing Dandelion Wine in an amazing summer of joy, however was terrified of this atomic holocaust when he pictured Earth both ruining itself and the intelligent far-advanced Martians from The Martian Chronicles.
From the late 20th century Michael Crichton, stressing about medical and computer viruses composes Armageddon stories such as Coma, Jurassic Park, and Andromeda Strain, but then attempted to convince us there is nothing to be frightened of about global warming in the condition of Fear.
From the conclusion of this 20th-century science fiction had become nearly synonymous with fantasy-magical Hobbit tales. You cannot tell if Neil Gaiman is telling a mythical magical narrative, once referred to as a children's story, or composing a narrative about grown-up men and women.
But today science has entered the domain of fiction, for example, by implementing hypothetical models of their surroundings, climate, world size, etc. Inventing two literary planets, and drawing on scientific decisions about the type of lifestyle would evolve there.