Planck-scale physics: facts and beliefs

TL;DR

This paper critically examines the assumption that Planck-scale physics is fundamental to quantum gravity, emphasizing the need to distinguish between established facts and speculative beliefs in this area.

Contribution

It clarifies the distinction between facts and beliefs regarding the significance of the Planck scale in quantum gravity research.

Findings

Highlights the lack of empirical evidence for Planck-scale relevance

Challenges the unexamined assumption of Planck units' fundamental role

Encourages rigorous scrutiny of foundational assumptions in quantum gravity

Abstract

The relevance of the Planck scale to a theory of quantum gravity has become a worryingly little examined assumption that goes unchallenged in the majority of research in this area. However, in all scientific honesty, the significance of Planck's natural units in a future physical theory of spacetime is only a plausible, yet by no means certain, assumption. The purpose of this article is to clearly separate fact from belief in this connection.