Purple, a 62-minute video project by the Ghana-born, London-based filmmaker John Akomfrah, owes a deep debt to Godfrey Reggio’s pioneering 1982 documentary, Koyaanisqatsi. Reggio’s film, set to a hypnotic score by Philip Glass, features dialogue-free footage of the natural and the man-made world, exploring visually striking themes of beauty, chaos, and decay, organized under the theme of the title, a Hopi word meaning “life out of balance.” Akomfrah cofounded the experimental film group Black Audio Film Collective in 1982, the same year Koyaanisqatsi came out, and Purple, now showing at the Hirshhorn, expands upon its predecessor, though with mixed results. Made in 2017, Purple one-ups Reggio’s film in a technical sense, using six screens in a semicircular array to show independent sequences of footage, heightening the phantasmagorical feel. For a strenuously pro-environment film—“purple” refers to the color of mourning in Ghanaian culture—you won’t see much David Attenborough-style portrayal of natural beauty, other than some impressive footage of schools of fish and falling snow. Even the recurring icy mountains of Greenland are shown less for their exquisiteness than as a foil for man’s footprint, in this case a mix of prettily painted buildings and barrel-strewn dumps. Through much of the movie, Akomfrah uses the multiscreen format to pair natural imagery with historical black-and-white footage, some of it familiar yet horrifying (aboveground nuclear explosions, grisly examinations of animal test subjects) and some of it bewilderingly humdrum (mid-century Britons doing everything from ballroom dancing to wiping snow off their windshields). Akomfrah returns frequently to pleasingly tranquil images of photographs he’s submerged in water; to an unexplained group of affluent people traveling on a yacht; and to windbreaker-clad figures posed under high-tension power lines. The power-line theme exposes the project’s key weakness: If electricity is so bad for the earth, what is the practical alternative, especially when Purple regularly demonizes nuclear power at the very moment it is gaining support for its carbon-free generation? Ultimately, Purple is absorbing, didactic, scattershot, and nerve-wracking; at least the museum has provided comfortable beanbag seats to use while watching it. Purple runs through January 2024 at the Hirshhorn Museum and Sculpture Garden. hirshhorn.si.edu. Free.