Grunt: The Curious Science of Humans at War, the new book by Mary Roach (W.W. Norton & Company; June 2016), was excerpted in the New York Times' Science section on May 30. Describing her visit to the Aberdeen Proving Ground (“a spread of high-security acreage set aside for testing weapons and the vehicles meant to withstand them"), Roach's first-person account offers her characteristic lively narrative and wry humor. She allows her guide, Mark Roman, to be ours as well. “'By and large, an army shows up to a war with the gear it has on hand from the last one.…