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Forever is a Day: Supertasks in Pitowsky and Malament-Hogarth Spacetimes

Published online by Cambridge University Press:  01 April 2022

John D. Norton*
Affiliation:
Department of History and Philosophy of Science, University of Pittsburgh

Abstract

The standard theory of computation excludes computations whose completion requires an infinite number of steps. Malament-Hogarth spacetimes admit observers whose pasts contain entire future-directed, timelike half-curves of infinite proper length. We investigate the physical properties of these spacetimes and ask whether they and other spacetimes allow the observer to know the outcome of a computation with infinitely many steps.

Type
Research Article
Copyright
Copyright © Philosophy of Science Association 1993

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Footnotes

We are grateful to David Malament and an anonymous referee for helpful suggestions on earlier drafts of this paper.

Send reprint requests to the authors, Department of History and Philosophy of Science, 1017 Cathedral of Learning, University of Pittsburgh, Pittsburgh, PA 15260, USA.

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