nLab Malament–Hogarth spacetime




Constructivism, Realizability, Computability



It has been argued that there are spacetimes which are such that they allow trajectories on which a computing device could travel indefinitely together with spacetime points at which an observer could observe the whole infinite history of the computer in finite time. If this indeed were physically realizable it would to some extent physically implement what is called hypercomputation. This would contradict, to some extent, the physical Church-Turing thesis, which asserts that no physical process can realize a computer more powerful than a Turing machine.


Original articles include

  • M. Hogarth, Does General Relativity Allow an Observer to View an Eternity in a Finite Time?, Foundations of Physics Letters, 5, 173–181 (1992)

Reviews include

See also

Discussion relating to the cosmic censorship hypothesis is in

  • Gabor Etesi, A proof of the Geroch-Horowitz-Penrose formulation of the strong cosmic censor conjecture motivated by computability theory (arXiv:1205.4550)

Last revised on March 17, 2014 at 06:47:48. See the history of this page for a list of all contributions to it.