How many universes are there? Author Brian Greene explains. Plus: A fracking update, a look at what’s next in Egypt and an interview author Parag Khanna.
Need to Know is a production of Creative News Group (CNG) in association with WNET. Marc Rosenwasser is Executive Producer. Need to Know is made possible by Bernard and Irene Schwartz, Mutual of America, Citi Foundation, John D. and Catherine T. MacArthur Foundation, Miriam and Ira D. Wallach Foundation, Margaret A. Cargill Foundation, The Corporation for Public Broadcasting and PBS.