Samuel Graydon at the TLS:
Enter Lee Smolin, a significant theoretical physicist who has made important contributions to the search for quantum gravity. He has bravely attempted to supply such a theory in his new book Einstein’s Unfinished Revolution. His argument is framed in terms of the divide between “realist” and “anti-realist” interpretations of nature. Realists argue that “matter [has] a stable set of properties in and of itself, without regard to our perceptions and knowledge”, and that “those properties can be comprehended and described by us”. Anti-realists, like the Copenhagenists, do not believe this, as quantum mechanics has features that “preclude realism” (such as the measurement problem). “Einstein was a realist. I am also a realist”, says Smolin, and this, he admits, rather backs him into a corner. If you are to go about asserting such madness as “there is a real world and we can understand it”, then you are forced to believe that quantum mechanics as it stands is false. “It may be temporarily successful, but it cannot be the fully correct description of nature at an atomic scale.”
more here.