In 1903, respected physicist Prosper-Rene Blondlot of the University of Nancy announced N-rays, a new form of radiation detected by watching a dim phosphorescent screen in a pitch-black room. Roughly 120 scientists went on to confirm them in about 300 published papers. None of it was real.

This episode examines the discovery gold rush that followed X-rays, radioactivity, and the electron; the physiology of rod cells and the autokinetic effect that let the eye invent changes in brightness; and the fall 1904 visit of American physicist Robert W. Wood, who quietly pocketed an aluminum prism in the dark while Blondlot kept narrating results. It also covers the aftermath, Irving Langmuir's concept of pathological science, and why Webster's still defined N-rays in 1946.

• Blondlot's credentials, including corresponding membership in the  ...