He is reading The Physics of Star Trek, by Lawrence M. Krauss. He enjoys reading books about science, and is a Star Trek fan. His favorite authors are Churchill (also), Ayn Rand, Theodore Roosevelt, William Wordsworth (see note below), and Ernest Hemingway. He said he couldn't think of a better story than Hemingway's The Old Man and the Sea.
Note about Wordsworth: Last summer I visited his cottage in Grasmere, England, where they had to keep the mutton fat candles in a box at night so the rats wouldn't eat them (beeswax cost too much).