The year is 1953 and the Langdon family gathers at their Iowa farm to say goodbye to their patriarch. The future of the farm is in question, as only one of the five children stays to work the land. This is how Jane Smiley’s latest novel begins. While last year’s “Some Luck” followed the Langdon family through the depression and into World War II, “Early Warning” tells their story as the country moves into the Cold War, through the social and sexual revolutions of the 1960s and ’70s and into the materialism of the ’80s. Smiley, the Pulitzer Prize-winning author of “A Thousand Acres,” joins us to talk about the latest installment in her “Last Hundred Years” trilogy.