Neil deGrasse Tyson was awed when he visited the Hayden Planetarium in New York City for the first time at the age of nine; since 1996, he's run the place. The rock-star astrophysicist, who has 7.2 million Twitter followers, can fill a theater with people eager to hear him talk science. And his latest book, "Astrophysics for People in a Hurry," offers...