Abstract

The quest for an all-encompassing theory, finally intended to give a solution to the problem of the unification of all natural forces, is seen today as one of the most important objectives of theoretical high-energy physics. This so-called 'Theory of Everything' is, actually, identified by some theoretical physicists with superstring theory. But superstring theory is in a crucial way incomplete. And, above all, it has fundamental problems with empirical testability – problems that make questionable its status as a physical theory at all.