Superstrings: Unification theory

Abstract

For the past twenty years, physicists have been intensively investigating the interesting and complex theory of superstrings. Despite much progress, fundamental aspects of the theory remain mysterious. When they were discovered in the late 1960s, superstrings were intended to explain hadrons. But the theory of quantum chromodynamics - a theory of quarks and gluons - was more successful, and strings, despite their early promise, were abandoned. At this time, superstring theory is the only candidate for a theory of all interactions - a unified theory of forces and matter. The complication that thwarted the search for a unified theory was the incompatibility between two of the most important pillars of twentieth-century physics: Einstein's general theory of relativity and the principles of quantum mechanics.