extreme popularity of string theory among theoretical physicists is partly a consequence of the financial structure of academia and the fierce competition for scarce resources. In his book The Road to Reality, mathematical physicist Roger Penrose expresses similar views, stating "The often frantic competitiveness that this ease of communication engenders leads to bandwagon effects, where researchers fear to be left behind if they do not join in." Penrose also claims that the technical difficulty of modern physics forces young scientists to rely on the preferences of established researchers, rather than forging new paths of their own. Lee Smolin expresses a slightly different position in his critique, claiming that string theory grew out of a tradition of particle physics which discourages speculation about the foundations of physics, while his preferred approach, loop quantum gravity, encourages more radical thinking. According to Smolin, Smolin goes on to offer a number of prescriptions for how scientists might encourage a greater diversity of approaches to quantum gravity research. Notes References Bibliography Further reading Popular science Textbooks External links Websites Not Even Wrong—A blog critical of string theory The Official String Theory Web Site Why String Theory—An introduction to string theory. Video bbc-horizon: parallel-uni — 2002 feature documentary by BBC Horizon, episode Parallel Universes focus on history and emergence of M-theory, and scientists involved. pbs.org-nova: elegant-uni — 2003 Emmy Award-winning, three-hour miniseries by Nova with Brian Greene, adapted from his The Elegant Universe (original PBS broadcast dates: October 28, 8–10 p.m. and November 4, 8–9 p.m., 2003). Mathematical physics Concepts in physics Dimension Multi-dimensional geometry Physical cosmology Physics beyond the Standard Model Theoretical physics