VENTURA, Calif. — When you are pushing 90, have written scores of famous novels, short stories and screenplays, and have fulfilled the goal of taking a simulated ride to Mars, what’s left?

“Bo Derek is a really good friend of mine and I’d like to spend more time with her,” said Ray Bradbury, peering up from behind an old television tray in his den.

An unlikely answer, but Mr. Bradbury, the science fiction writer, is very specific in his eccentric list of interests, and his pursuit of them in his advancing age and state of relative immobility.

Fiscal threats to libraries deeply unnerve Mr. Bradbury, who spends as much time as he can talking to children in libraries and encouraging them to read.