Fantasy is totally wide open; all you really have to do is follow the rules you've set. But if you're writing about science, you have to first learn what you're writing about.
Octavia ButlerScience fiction let me do both. It let me look into science and stick my nose in everywhere.
Octavia ButlerWriting is one of the few professions in which you can psychoanalyse yourself, get rid of hostilities and frustrations in public, and get paid for it.
Octavia ButlerNo... a novel is a long business. I'm a slow writer, even when I'm doing very well I write slowly.
Octavia Butler