Foundations of Physics Letters

, Volume 18, Issue 4, pp 379–385

Can a Circulating Light Beam Produce a Time Machine

Original Article

DOI: 10.1007/s10702-005-7127-4

Cite this article as:
Olum, K. & Everett, A. Found Phys Lett (2005) 18: 379. doi:10.1007/s10702-005-7127-4

Abstract

In a recent paper, Mallett found a solution of the Einstein equations in which closed timelike curves (CTC’s) are present in the empty space outside an infinitely long cylinder of light moving in circular paths around an axis. Here we show that, for physically realistic energy densities, the CTC’s occur at distances from the axis greater than the radius of the visible universe by an immense factor. We then show that Mallett’s solution has a curvature singularity on the axis, even in the case where the intensity of the light vanishes. Thus it is not the solution one would get by starting with Minkowski space and establishing a cylinder of light.

Key words:

general relativity cylindrically symmetric solutions of Ein-stein’s equation closed timelike curves curvature singularity circulating light beam 

Copyright information

© Springer Science+Business Media, Inc. 2005

Authors and Affiliations

  1. 1.Department of Physics and Astronomy, Institute of CosmologyTufts UniversityMedfordMassachusetts