Gregory Benford and Larry Niven, who recently collaborated on The Bowl of Heaven,

From YouTube:

Larry Niven & Gregory Benford, two of the most respected authors of hard science fiction, talk about their new book Bowl of Heaven and the concept of stories about “big dumb objects” as a sub-genre. They review prior stories (including Ringworld by Niven) and then talk about the physics of the “big smart object” that is the Bowl of Heaven — a half dyson-sphere steering a star on an interstellar voyage.