Recently at TED2010, Bill Gates unveiled his vision for the world's energy future, which includes, in Gates' estimation, the need for "miracles" to avoid planetary catastrophe. The necessary goal? Zero carbon emissions globally by 2050. How are we going to get there? Gates thinks one of the ways will be to embrace a dramatically different type of nuclear reactor. But not everyone is buying Bill Gates' argument, including Dave Roberts of Grist. Watch Bill Gates recently at TEDTalks and you decide for yourself if he's onto something.