We may take light for granted, but for some two-billion people around the globe, reliable, economical light sources are unavailable. In this episode of Lighting the World, John Bowers of UC Santa Barbara’s Institute for Energy Efficiency describes this problem and how they are using the highly efficient white LED, discovered by Shuji Nakamura, as a solution. Series: "Lighting the World: Shuji Nakamura and His Brilliant Discovery" [Science] [Show ID: 24738]