String theory, or superstring theory, is mathematics that replaces zero-dimensional points (particles) with one-dimensional strings as the fundamental building block of physics. The hope is resolve conflicts between gravity and quantum mechanics in existing models of physics. The elusive goal is to develop a set of equations that unify all known natural forces (gravitational, electromagnetic, weak and strong). A leading proponent of string theory has been Edward Witten of the Institute for Advanced Study.
Increasingly critics have questioned whether string theory qualifies as science. There is no experimental verification or falsification for the theory, and string theory appears to be based on mathematics rather than physical observation. Under the concept of science advanced by Karl Popper, string theory would not even qualify as science.