“Doctor Atomic will surely not deliver history’s final verdict on Robert Oppenheimer. It may, however, lay to rest persistent misconceptions about John Adams’s work, which has been described since “Nixon in China” as “CNN opera.” The label applies well enough to other operas “ripped from the headlines.” But it never really applied to the Adams operas, which sought from the first to lend topical subjects the timelessness and ambiguity of myth.”