String Theory: The Early Years

This is a completely reformulated presentation of a previous paper with the same title; this time with a much stronger emphasis on conceptual aspects of string theory and a detailed review of its already more than four decades lasting history within a broader context, including some little-known details. Although there have been several books and essays on the sociological impact and its philosophical implications, there is yet no serious attempt to scrutinize its claims abou...

This essay presents a critical evaluation of the concepts of string theory and its impact on particle physics. The point of departure is a historical review of four decades of ST within the broader context of six decades of failed attempts at an autonomous S-matrix approach to particle theory. The central message, contained in sections 5 and 6, is that string theory is not what its name suggests, namely a theory of of objects in spacetime whose localization is string- instead...

This is a brief review of the present status, of some recent developments and of the open challenges in string/M theory.

This contribution, aimed mostly at experimental particle physicists, reviews some of the main ideas and results of String Theory in a non-technical language. It originates from the talks presented by the authors at the Electro-Weak session of the 2002 Moriond Meeting, here merged in an attempt to provide a more complete and concise view of the subject.

The 1988 book, now free, with corrections and bookmarks (for pdf).

A few recollections and afterthoughts on the development of the string picture of fundamental interactions out of the S-matrix program.

String theory is at the moment the only advanced approach to a unification of all interactions, including gravity. But, in spite of the more than thirty years of its existence, it does not make any empirically testable predictions, and it is completely unknown which physically interpretable principles could form the basis of string theory. At the moment, "string theory" is no theory at all, but rather a labyrinthic structure of mathematical procedures and intuitions. The only...

Much of the recent progress in String Theory can be traced to a precise strategy: a careful study of the few models known since the beginnings of the subject, and the abstraction from them of basic properties that one would like to demand from other models. This could be termed a set of "model-building rules". The approach corresponds to the fact, often a source of embarrassment to specialists, that String Theory, born as a set of rules rather than as a set of principles, has...

Lectures presented at the Spring School, Trieste, Italy 1993.

This is the written version of a short talk given at the University of Leipzig in December 1998. It reviews some general aspects of string theory from the viewpoint of the search for an unifying theory. Here, special emphasis lies on the motivation to consider string theory not only as the leading candidate for the unification of gravity and the other fundamental forces of nature, but also as a possible step towards a new understanding of nature and its description within the...