[2016-04-20 13:00:00] Every minute, hundreds of hours of video are uploaded to YouTube and millions of photographs are snapped on our smartphones. This hour, we’ll talk about how “visual activism” is driving social and political change with Nicholas Mirzoeff, professor of media culture and communication at NYU and deputy director of the International Association for Visual Culture. His new book is called “How to See the World: An Introduction to Images, from Self-Portraits to Selfies, Maps to Movies, and More” (Basic Books).