Physics World has an interview with Alastair Reynolds, who was trained as an astrophysicist but is now a full-time SF author:
How does your physics training help with your writing?
Less than people imagine. I think the most important attribute for a science-fiction writer is to be fascinated by science — in all its manifestations. It’s not necessary to be able to understand all the details, but just to be inspired and stimulated. Most of the ideas that have fed into my writing have come from reading popular articles on subjects far away from my own very limited specialization, such as neuroscience or biology.
I was on a panel with Reynolds a few Boskones ago, and he was a nice guy who made the best of a mildly bad situation– the panel was on disaster novels, and none of the panelists really had much of anything to say about the topic, so we just sort of threw it open to the audience, and let them talk. He was a really good sport about the whole thing.
I read and enjoyed his first novel, Revelation Space, and I’ve got another book or two by him kicking around somewhere. He’s worth a look, and the interview is short but interesting.