"...perhaps I can offer a not-too-biased perspective on why many of us think that string theory has an extremely good chance of being right. It successfully combines Einstein's theory of general relativity with quantum mechanics; it unifies the four fundamental forces of nature in a beautiful and elegant way; it appears to contain the Standard Model as a low-energy approximation; it has an amazing richness, depth and mathematical consistency; it has helped us to unravel deep puzzles concerning the nature of black holes; it is well-defined and allows researchers to reach clear and unambiguous answers to questions they pose; it incorporates "supersymmetry," which many workers even outside of string theory believe will be a feature of the new physics." Wow, with all that going for it I certainly hope this is a big idea that won't die.