Clearly there is still expectation that science fiction writers should have scientific credentials in order to write SF, especially if they turn out to have (non-fiction) ideas and opinions about what they’re writing. As illustration, here’s a blog by Charlie Stross back in 2011, revealing a contentious email exchange with a student in search of sources. After posting the argument, Stross asks, “Is the culture of spurious credentialism toxic to intellectual exploration?”

Long story short, Stross had a cold and couldn’t deal with fiction, so he wrote up his opinions about actual space colonization on his blog. This led to comments, and eventually questions about why he thought he was authority enough to write the essay. Stross does have credentials in chemistry and computer science, but not in astrophysics. Apparently his questioner felt Stross’ background didn’t qualify him to write a non-fiction essay on space.

Stross writes hard SF well, and no one has questioned his fiction. He notes that he researches and studies to make his fiction realistic and science-based. This means Stross is diligent and interested in his subject matter. He is well-informed about space because of his research and he’s put a lot of thought into it. This means he is, indeed, an authority on space colonization, enough so that he is invited to give lectures on the subject. It also suggests that other SF authors can be experts, too. It’s just a matter of study and imagination.

What Stross is saying is that writers can make projections in their fiction, but it has to be based on real science in order to be real science fiction. If the science isn’t there, it’s just a futuristic setting for a fantasy story.