Does Locality Fail at Intermediate Length-Scales

Abstract

If quantum gravity implies a fundamental spatiotemporal discreteness, and if its ``laws of motion'' are compatible with the Lorentz transformations, then physics cannot remain local. One might expect this nonlocality to be confined to the fundamental discreteness scale, but I will present evidence that it survives at much lower energies, yielding for example a nonlocal equation of motion for a scalar field propagating on an underlying causal set.

plainTeX, 24 pages, 2 figures. To appear in Daniele Oriti (ed.), {\it Towards Quantum Gravity} (Cambridge University Press, 2007). Most current version is available at http://www.physics.syr.edu/~sorkin/some.papers/ (or wherever my home-page may be)