The variety of lights—glittering constellations, moon, explosions, electrical mishaps, the earth—that Russell H. Champa has produced abundantly in The Light Years are inventive and terrific. They don’t, however, illuminate what playwrights Hannah Bos and Paul Thureen are getting at. Inspired by Bos’s childhood remembrances of family members who spoke of two world’s fairs held in Chicago, in 1893 and 1933, and by director Oliver Butler, who knew about real-life theatrical impresario Steele Mackaye, a forgotten innovator. Developed by Bos and Thureen for the Debate Society, The Light Years is a sort of pageant play glorifying scientific progress and human aspirations in the form of the inventions presented at the American expositions.