What represents space-time? And what follows for substantivalism vs. relationalism and gravitational energy?

In Antonio Vassallo (ed.), The Foundations of Spacetime Physics: Philosophical Perspectives. New York, NY: Routledge (2022)
  Copy   BIBTEX

Abstract

The questions of what represents space-time in GR, the status of gravitational energy, the substantivalist-relationalist issue, and the exceptional status of gravity are interrelated. If space-time has energy-momentum, then space-time is substantival. Two extant ways to avoid the substantivalist conclusion deny that the energy-bearing metric is part of space-time or deny that gravitational energy exists. Feynman linked doubts about gravitational energy to GR-exceptionalism, as do Curiel and Duerr; particle physics egalitarianism encourages realism about gravitational energy. In that spirit, this essay proposes a third possible view about space-time, one involving a particle physics-inspired non-perturbative split that characterizes space-time with a constant background _matrix_, a sort of vacuum value, thus avoiding the inference from gravitational _energy to substantivalism. On this proposal, space-time is, where eta=diag is a spatio-temporally constant numerical signature matrix, a matrix already used in GR with spinors. The gravitational potential, to which any gravitational energy can be ascribed, is g_{\mu\nu}- eta, an _affine_ geometric object with a tensorial Lie derivative and a vanishing covariant derivative. This non-perturbative split permits strong fields, arbitrary coordinates, and arbitrary topology, and hence is pure GR by almost any standard. This razor-thin background, unlike more familiar backgrounds, involves no extra gauge freedom and so lacks their obscurities and carpet lump-moving. After a discussion of Curiel's GR exceptionalist denial of the localizability of gravitational energy and his rejection of energy conservation, the two traditional objections to pseudotensors, coordinate dependence and nonuniqueness, are explored. Both objections are inconclusive and getting weaker. A literal interpretation involving infinitely many energies corresponding by Noether's first theorem to the infinite symmetries of the _action_ largely answers Schroedinger's false-negative coordinate dependence problem. Bauer's false-positive objection has multiple answers. Non-uniqueness might be handled by Nester et al.'s finding physical meaning in multiplicity in relation to boundary conditions, by an optimal candidate, or by Bergmann's identifying the non-uniqueness and coordinate dependence ambiguities as one.

Links

PhilArchive



    Upload a copy of this work     Papers currently archived: 92,813

External links

Setup an account with your affiliations in order to access resources via your University's proxy server

Through your library

Similar books and articles

Identity, space-time, and cosmology.Jan Faye - 2008 - In Dennis Geert Bernardus Johan Dieks (ed.), The Ontology of Spacetime II. Elsevier. pp. 39-57.
Relative Locations.Andrew Bacon - forthcoming - Oxford Studies in Metaphysics (1):44-94.
Localization of gravitational energy.Nathan Rosen - 1985 - Foundations of Physics 15 (10):997-1008.
Rehabilitating relationalism.Gordon Belot - 1999 - International Studies in the Philosophy of Science 13 (1):35 – 52.
Gravity, Metaphysics or Physics ?Alfonso Leon Guillen Gomez - 2013 - International Journal of Fundamental Physical Sciences 3 (4):68 - 74.

Analytics

Added to PP
2022-04-03

Downloads
25 (#650,721)

6 months
9 (#352,458)

Historical graph of downloads
How can I increase my downloads?

Author's Profile

J. Brian Pitts
University of Lincoln

References found in this work

Quantum Gravity.Carlo Rovelli - 2007 - Cambridge University Press.
What price spacetime substantivalism? The hole story.John Earman & John Norton - 1987 - British Journal for the Philosophy of Science 38 (4):515-525.
Space-Time-Matter.Hermann Weyl - 1922 - London,: E.P. Dutton and Company. Edited by Henry L. Brose.

View all 28 references / Add more references