. . . . . . . . . "3"^^ . . . . . "Season 4"@en . . . . "2010-02-01"^^ . . . . . . . . . . . "14"^^ . . . . . . . . . . . . . . . "Sheldon's search for the answer to a physics problem (Why electrons behave as if they have no mass when traveling through a graphene sheet) keeps him awake for several days and he becomes obsessed with trying to solve it acting crazier than normal."@en . . . . . "Sheldon's search for the answer to a physics problem (Why electrons behave as if they have no mass when traveling through a graphene sheet) keeps him awake for several days and he becomes obsessed with trying to solve it acting crazier than normal."@en . . "The Einstein Approximation"@en . . . . . "Sheldon working at his whiteboard."@en . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . "Season 2"@en . . . . . . . "The Einstein Approximation"@en . . . . . . . . . . . .