Hidden

What lies beyond the reach of the naked eye, and how do these hidden forces shape our lives? This hour, TED speakers reveal forgotten cities, underwater canyons, tiny parasites, and a boiling river. TED speakers include computer scientist Abe Davis, ocean explorer Robert Ballard, science writer Ed Yong, space archaeologist Sarah Parcak, and geoscientist Andrés Ruzo. (Original broadcast date: March 18, 2016)