In 1994, Stephen W. Hawking and Roger Penrose gave a series of lectures which culminated in a debate about how universal and applicable the theories of quantum mechanics and relativity are. (Their lectures and debate were published in book form in 1996 under the title The Nature of Space and Time, Hawking and Penrose, Princeton Univ. Press.) Since that was more than a decade ago, I was wondering what advances or discoveries were made since then that might have changed their views or positions. What now is the current thinking of mainstream physicists who work in these areas? Have either Hawking or Penrose changed their minds? I do believe, for example, that Penrose has more or less stopped research on his twistor theory.