This modern movie milestone, from 1959, was conceived as a documentary, but director Alain Resnais had the courage and wisdom to consider that form profoundly unequal to its task, opting instead for a romantic duet written by novelist Marguerite Duras. Hiroshima Mon Amour was Resnais’ first feature, but he’d already made the short documentary Night and Fog, about Nazi death camps, in part by seeming uniquely cognizant of Theodor Adorno’s famous claim that “to write poetry after Auschwitz is barbaric.” So what of atomic cataclysm? Is it possible to bear witness to the unspeakable with only an allowance of sweet nothings? In Resnais and Duras’ deceptively simple scenario, set to stinging music by Georges Delerue and Giovanni Fusco, Emmanuelle Riva plays a French actress staying briefly in Hiroshima to make a movie “about peace,” and Eiji Okada plays her lover, a Japanese architect. The affair transpires in languorous interludes, a deliberately irresolute co-mingling of past and present tense. This was an early experiment in narrative nonlinearity — a film in which, as its own maker claimed, “time is shattered.” Of course that viewpoint has a moral aspect, hence the paradox of a work as grave as it is luminous, and so heavy with history that it still feels fresh more than half a century after being made.