The Heuristic Function of Duality

TL;DR

This paper explores the duality concept in quantum gravity, distinguishing between their roles in identifying equivalent theories and in guiding the discovery of new physics, emphasizing the heuristic function for theory development.

Contribution

It introduces and clarifies the heuristic function of dualities, highlighting its importance in formulating new theories and differentiating it from the theoretical function of dualities.

Findings

Dualities serve both to identify equivalent theories and to suggest new physics.

The heuristic function of dualities can aid in discovering and formulating new theories.

A schema for dualities clarifies the distinction between their theoretical and heuristic roles.

Abstract

I conceptualise the role of dualities in quantum gravity, in terms of their functions for theory construction. I distinguish between two functions of duality in physical practice: namely, discovering and describing 'equivalent physics', vs. suggesting 'new physics'. I dub these the 'theoretical' vs. the 'heuristic' functions of dualities. The distinction seems to have gone largely unnoticed in the philosophical literature: and it exists both for dualities, and for the more general relation of theoretical equivalence. The paper develops the heuristic function of dualities: illustrating how they can be used, if one has any luck, to find and formulate new theories. I also point to the different physical commitments about the theories in question that underlie these two functions. I show how a recently developed schema for dualities articulates the differences between the two functions.