"In my view, the most significant discovery of the annotations is that Gravity's Rainbow unfolds according to a circular design. Across the novel's four parts, historical events intersect the Christian liturgical calendar, inferring possibilities for return and renewal, but possibilities that Pynchon's satire hopelessly equivocates. This means that readers might have a novel as elegantly modeled as Joyce's Ulysses and have their deconstructionism too. Indeed, one might well read Gravity's Rainbow as the terrible dynamic of a culture huddling on the brink of nuclear winter."
--A Gravity's Rainbow Companion: Sources and Contexts for Pynchon's Novel by Steven Weisenburger