Rudy Rucker watches as his paintings are hung in Borderlands Bookstore Cafe, where he will discuss his art and new novel “Return to the Hollow Earth” at 3 p.m. on Saturday. Rucker won the first Philip K. Dick award for his cyberpunk novel “Software” in 1983 and won again for “Wetware” in 1988. He taught computer science at San Jose State University from 1986 to 2004. After taking an oil painting class with his wife, he has painted for twenty years. “It’s even more meditative than writing,” he once explained to another science fiction author, Terry Bisson. “I tend to surprise myself with what I end up painting.”