If you have a gnawing sense that this is end of the world as we know it, then know this: You’re not alone. Apocalyptic dread is as old as human history. So, chances are good that this too will pass. But what if it doesn’t? What if the end really is nigh. Well, in that case, Athena Aktipis has some advice for you. In her new book, “A Field Guide to the Apocalypse,” Aktipis says that you, too, can survive and thrive in all sorts of dystopian future scenarios. And, she says, you might even enjoy it.