‘Oppenheimer’ a momentous achievement, at times pensive, at times explosive

Cillian Murphy stars as J. Robert Oppenheimer in “Oppenheimer.” (Universal Pictures)

Magnificent.

Christopher Nolan’s three-hour historical biopic “Oppenheimer” is a gorgeously photographed, brilliantly acted, masterfully edited and thoroughly engrossing epic that instantly takes its place among the finest films of this decade — an old-fashioned yet cutting-edge work that should resonate with film scholars and popcorn-toting mainstream movie lovers for years and decades to come.