String fellows100 years after Einstein changed physics for ever, Alok Jha visits a leafy corner of Princeton to meet his intellectual heirs - still hunting for a theory of everythingAlok JhaThursday January 20, 2005GuardianEdward Witten is so softly spoken that his voice sometimes threatens to drift away completely. His desk is a jumble of papers and his blackboard a mess of equations. But his hushed words come straight to the point and are infused with understanding and passion.Witten's quiet manner belies his status. In his role as de facto scientist-in-chief of string theory, Witten, the Charles Simonyi professor of mathematical...