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General relativistic hypercomputing and foundation of mathematics

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Abstract

Looking at very recent developments in spacetime theory, we can wonder whether these results exhibit features of hypercomputation that traditionally seemed impossible or absurd. Namely, we describe a physical device in relativistic spacetime which can compute a non-Turing computable task, e.g. which can decide the halting problem of Turing machines or decide whether ZF set theory is consistent (more precisely, can decide the theorems of ZF). Starting from this, we will discuss the impact of recent breakthrough results of relativity theory, black hole physics and cosmology to well established foundational issues of computability theory as well as to logic. We find that the unexpected, revolutionary results in the mentioned branches of science force us to reconsider the status of the physical Church Thesis and to consider it as being seriously challenged. We will outline the consequences of all this for the foundation of mathematics (e.g. to Hilbert’s programme). Observational, empirical evidence will be quoted to show that the statements above do not require any assumption of some physical universe outside of our own one: in our specific physical universe there seem to exist regions of spacetime supporting potential non-Turing computations. Additionally, new “engineering” ideas will be outlined for solving the so-called blue-shift problem of GR-computing. Connections with related talks at the Physics and Computation meeting, e.g. those of Jerome Durand-Lose, Mark Hogarth and Martin Ziegler, will be indicated.

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Notes

  1. As a contrast, one of the founding fathers of PhCT, László Kalmár, always hoped for a refutation of PhCT and to his students he emphasized that PhCT is meant to be a challenge to future generations, it is aimed at “teasing” researchers to put efforts into attacking PhCT (Kalmár 1959).

  2. Measurable e.g. by radar.

  3. This is a technical expression in observational astronomy.

  4. Very tentatively: Recently, emerging new kinds of computing devices like the Internet seem to pose a challenge against the conjecture in Question 1 (cf. Wiedermann and van Leeuwen 2002). However, even the Internet (or even the Human Mind) will probably not prove ZFC consistent (assuming C6). So, perhaps we should separate PhCT into two theses, one about “hard” problems like proving the consistency of ZFC, and the other about problems in general which are not Turing computable.

References

  • Andréka H, Németi I (2007) Relativistic computers and Hilbert’s Program for mathematics. Manuscript

  • Andréka H, Madarász JX, Németi I, with contributions from Andai A, Sain I, Sági G, Tőke Cs, Vályi S (2000) On the logical structure of relativity theories. Internet book, Budapest. http://www.math-inst.hu/pub/algebraic-logic/olsort.html

  • Andréka H, Madarász JX, Németi I (2007) Logic of spacetime and relativity theory. In: Aiello M, van Benthem J, Pratt-Hartman I (eds) Handbook of spatial logics. Springer-Verlag, pp 607–711

  • Andréka H, Madarász JX, Németi I, Székely G (2008a) Axiomatizing relativistic dynamics without conservation postulates. Studia Logica 89(2):163–186

    Article  MATH  MathSciNet  Google Scholar 

  • Andréka H, Németi I, Wüthrich (2008b) A twist in the geometry of rotating black holes: seeking the cause of acausality. Gen Relativ Gravitat 40(9):65–89

    Google Scholar 

  • Barrow JD (2005) How to do an infinite number of things before breakfast. New Scientist, 29 January 2005

  • Barrow JD, Tipler FJ (1986) The anthropic cosmological principle. Oxford University Press, UK

  • Chown M (2002) Smash and grab. New Scientist, 6 April 2002, pp 24–28

  • Cooper SB (2006) How can nature help us compute? In: Wiedermann J, Stuller J, Tel G, Pokorny J, Bielikova M, (eds) SOFSEM 2006: theory and practice of computer science—32nd conference on current trends in theory and practice of computer science, Merin, Czech Republic, January 2006. Springer lecture notes in computer science no. 3831, pp 1–13

  • Dávid Gy (2005) Modern cosmology—astronomical, physical and logical approaches. Abstracts for the conference “Logic in Hungary 2005”. http://atlas-conferences.com/cgi-bin/abstract/caqb-64

  • Earman J (1995) Bangs, crunches, whimpers, shrieks. Singularities and acausalities in relativistic spacetimes. Oxford University Press, Oxford

  • Earman J, Norton J (1993) Forever is a day: supertasks in Pitowsky and Malament-Hogarth spacetimes. Philos Sci 60 :22–42

    Article  MathSciNet  Google Scholar 

  • Earman J, Norton J (1994) Infinite pains: the trouble with supertasks. In: Stich S (ed) Paul Benacerraf: the Philosopher and his critics. Blackwell, New York

    Google Scholar 

  • Etesi G (2002) Note on a reformulation of the strong cosmic censor conjecture based on computability. Phys Lett B 550:1–7. Revised version (2008)

    Google Scholar 

  • Etesi G, Németi I (2002) Turing computability and Malament-Hogarth spacetimes. Int J Theor Phys 41(2):342–370

    Article  Google Scholar 

  • Gödel K (1995) Lecture on rotating universes. In: Feferman S, Dawson JS, Goldfarb W, Parson C, Solovay RN (eds) Kurt Gödel collected works, vol 3. Oxford University Press, New York, pp 261–289

    Google Scholar 

  • Gyenis B, Roberts B (2007) Supertasks: Gödel strikes back. Preprint, Department of History and Philosophy of Science, University of Pittsburgh

  • Hogarth ML (1994) Non-Turing computers and non-Turing computability. In: Hull D, Forbes M, Burian RM (eds) PSA 1994, vol 1. Philosophy of Science Association, East Lansing, pp 126–138

  • Hogarth ML (2000) Predictability, computability, spacetime. PhD Dissertation, University of Cambridge, UK. http://ftp.math-inst.hu/pub/algebraic-logic/Hogarththesis.ps.gz

  • Hogarth ML (2004) Deciding arithmetic using SAD computers. Br J Philos Sci 55:681–691

    Article  MATH  MathSciNet  Google Scholar 

  • Kalmár L (1959) An argument against the plausibility of Church’s thesis. In: Heyting A (ed) Constructivity in mathematics. North-Holland, Amsterdam

  • Loff B, Costa JF (2009) Five views of hypercomputation. Int J Unconv Comput, Special Issue on Hypercomputation (in print)

  • Madarász JX, Székely G (2005) The effects of gravitation on clocks, proved in axiomatic relativity. Abstracts for the conference “Logic in Hungary 2005”, http://atlas-conferences.com/cgi.bin/abstract.caqb-41

  • Madarász JX, Németi I, Székely G (2006) Twin Paradox and the logical foundation of space-time. Found Phys 36(5):681–714. arXiv:gr-qc/0504118

    Article  MATH  MathSciNet  Google Scholar 

  • Madarász JX, Németi I, Székely G (2007) First-order logic foundation of relativity theories. In: Mathematical problems from applied logic II. International Mathematical Series, vol 5, Springer-Verlag, New York, pp 217–252

  • Malament D (1988) Private communication to Earman, J., Cf. Earman’s book in the present list of references, p 238

  • Németi I (1965) Computing the disturbance of phone lines caused by high-voltage electrical power lines. Master Thesis, Department of Electrodynamics, Technical University Budapest

  • Németi I (1987) On logic, relativity, and the limitations of human knowledge. Iowa State University, Department of Mathematics, Ph.D. course during the academic year 1987/88

  • Németi I, Andréka H (2006) Can general relativistic computers break the Turing barrier? In: Beckmann A, Berger U, Löwe B, Tucker JV (eds) Logical approaches to computational barriers, second conference on computability in Europe, CiE 2006, Swansea, UK. Proceedings, lecture notes in computer science 3988, Springer-Verlag, Berlin, pp 398–412

  • Németi I, Dávid Gy (2006) Relativistic computers and the Turing barrier. J Appl Math Comput 178:118–142

    Article  MATH  Google Scholar 

  • O’Neill B (1995) The geometry of Kerr black holes. A K Peters, Wellesley

    MATH  Google Scholar 

  • Ori A (1997) On the traversability of the Cauchy horizon: Herman and Hiscock’s argument revisited. In: Ori A, Ori LM (eds) Internal structures of black holes and spacetime singularitites. Ann Isra Phys Soc 13, IOP

  • Pitowsky I (1990) The physical Church thesis and physical computational complexity. Iyyun A Jerus Philos Q 39:81–99

    Google Scholar 

  • Pour-El MB, Richards JI (1989) Computability in analysis and physics. Springer-Verlag, Berlin

    MATH  Google Scholar 

  • Reynolds CC, Brenneman LW, Garofalo D (2004) Black hole spin in AGN and GBHCs. Oct. 5. arXiv:astro-ph/0410116 (Evidence for rotating black holes)

  • Sági G, Etesi G (2005) Transfinite computations and diameters of spacetimes.Hungarian Academy of Sciences, Budapest

  • Shagrir O, Pitowsky I (2003) Physical hypercomputation and the Church-Turing Thesis. Minds Mach 13:87–101

    Article  MATH  Google Scholar 

  • Strohmayer TE (2001) Discovery of a 450 HZ quasi-periodic oscillation from the microquasar GRO J1655-40 with the Rossi X-Ray timing explorer. Astrophys J 553(1):L49–L53. (Evidence for rotating black holes.) arXiv:astro-ph/0104487

    Google Scholar 

  • Syropoulos A (2008) Hypercomputation. Springer

  • Taylor EF, Wheeler JA (2000) Black holes. Addison-Wesley, Longman, San Francisco

    Google Scholar 

  • Tegmark M (2003) Parallel universes. Scientific American, May 2003, pp 41–51

  • Tipler FJ (1994) The physics of immortality. Anchor Books, New York

    Google Scholar 

  • van Leeuwen J, Wiedermann J (2001) The Turing Machine paradigm in comtemporary computing. In Enquist B, Schmid W (eds) Mathematics unlimited—2001 and beyond. Springer-Verlag, Berlin, pp. 1139–1155

    Google Scholar 

  • Wald RM (1984) General relativity. University of Chicago Press, Chicago

    MATH  Google Scholar 

  • Welch PD (2008) On the extent of computation in Malament-Hogarth spacetimes. Brit J Philos Sci 59(4): 659–674. arXiv:gr-qc/0609035v1

    Google Scholar 

  • Wiedermann J, van Leeuwen J (2002) Relativistic computers and non-uniform complexity theory. In: Calude et al (eds) UMC 2002 Lecture notes in computer science Vol 2509. Springer-Verlag, Berlin, pp. 287–299

    Google Scholar 

  • Wischik L (1997) A formalization of non-finite computation. Dissertation for the degree of Master of Philosophy, University of Cambridge. http://www.wischik.com/lu/philosophy/non-finite-computation.html

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Acknowledgements

Special thanks are due to Gyula Dávid for intensive cooperation and ideas on this subject. We are grateful for enjoyable discussions to Attila Andai, John Earman, Gábor Etesi, Stefan Gruner, Balázs Gyenis, Mark Hogarth, Judit Madarász, Victor Pambuccian, Gábor Sági, Endre Szabó, László E. Szabó, Renáta Tordai, Sándor Vályi, Jir̂i Wiedermann, Chris Wüthrich. We gratefully acknowledge support by the Hungarian National Foundation for scientific research grant No. T73601.

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Andréka, H., Németi, I. & Németi, P. General relativistic hypercomputing and foundation of mathematics. Nat Comput 8, 499–516 (2009). https://doi.org/10.1007/s11047-009-9114-3

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