String and M-theory: answering the critics

TL;DR

This paper defends string and M-theory as promising unified theories of fundamental interactions, addressing criticisms and highlighting their diverse applications in physics and mathematics to justify their ongoing research despite unresolved issues.

Contribution

It provides a layman's explanation of the importance of unified theories and responds to criticisms, emphasizing the broad applicability of string/M-theory techniques.

Findings

String/M-theory offers the best current hope for a unified fundamental theory.

Techniques from string/M-theory have valuable applications across physics and mathematics.

The enterprise remains worthwhile regardless of achieving a complete 'theory of everything'.

Abstract

Using as a springboard a three-way debate between theoretical physicist Lee Smolin, philosopher of science Nancy Cartwright and myself, I address in layman's terms the issues of why we need a unified theory of the fundamental interactions and why, in my opinion, string and M-theory currently offer the best hope. The focus will be on responding more generally to the various criticisms. I also describe the diverse application of string/M-theory techniques to other branches of physics and mathematics which render the whole enterprise worthwhile whether or not "a theory of everything" is forthcoming.