The one and only Bill Nye the Science Guy (@BillNye) is the subject of a new documentary all about his life. He talks to Sam about the film, how he thinks fame has changed his brain, a troubling degenerative disease that afflicts his family, and his advocacy of climate science. Email the show at samsanders@npr.org or tweet @NPRItsBeenAMin with your feedback. Follow Sam on Twitter @samsanders and producers Brent Baughman @brentbaughman and Anjuli Sastry @AnjuliSastry.