A non-fiction writer pretty much has the shape of the figure in front of him or her and goes about refining it. A work of non-fiction is not as difficult to write as a work of fiction, but it's not as satisfying in the end.
To the extent that I come from a deeply religious tradition and have been contending with those beginnings all of my life - that constitutes the subject of much of my early fiction.
If you don't care about science enough to be interested in it on its own, you shouldn't try to write hard science fiction. You can write like Ray Bradbury and Harlan Ellison as much as you want.
My old English buddy, John Rackham, wrote and told me what made science fiction different from all other kinds of literature - science fiction is written according to the science fiction method.
Stephen Hawking said he spent most of his first couple of years at Cambridge reading science fiction (and I believe that, because his grades weren't all that great).
It's important, I think, for a writer of fiction to maintain an awareness of the pace and shape of the book as he's writing it. That is, he should be making an object, not chattering.
