Consequences of Undecidability in Physics on the Theory of Everything
Document Type : Letter
Authors
1 Irving K. Barber School of Arts and Sciences, University of British Columbia Okanagan, Kelowna, BC V1V 1V7, Canada; Canadian Quantum Research Center, 204-3002 32 Ave, Vernon, BC V1T 2L7, Canada; Department of Mathematical Sciences, Durham University, Upper Mountjoy, Stockton Road, Durham DH1 3LE, UK; Faculty of Sciences, Hasselt University, Agoralaan Gebouw D, Diepenbeek, 3590 Belgium.
2 Origin Project Foundation, Phoenix, AZ 85018, USA.
3 Canadian Quantum Research Center, 204-3002 32 Ave, Vernon, BC V1T 2L7, Canada.
4 CNR-Istituto Nazionale di Ottica and INFN, Via Sansone 1, I-50019 Sesto Fiorentino (FI), Italy.
Abstract
General relativity treats spacetime as dynamical and exhibits its breakdown at singularities. This failure is interpreted as evidence that quantum gravity is not a theory formulated {within} spacetime; instead, it must explain the very {emergence} of spacetime from deeper quantum degrees of freedom, thereby resolving singularities. Quantum gravity is therefore envisaged as an axiomatic structure, and algorithmic calculations acting on these axioms are expected to generate spacetime. However, Gödel’s incompleteness theorems, Tarski’s undefinability theorem, and Chaitin’s information-theoretic incompleteness establish intrinsic limits on any such algorithmic program. Together, these results imply that a wholly algorithmic “Theory of Everything’’ is impossible: certain facets of reality will remain computationally undecidable and can be accessed only through non-algorithmic understanding. We formalize this by constructing a “Meta-Theory of Everything’’ grounded in non-algorithmic understanding, showing how it can account for undecidable phenomena and demonstrating that the breakdown of computational descriptions of nature does not entail a breakdown of science. Because any putative simulation of the universe would itself be algorithmic, this framework also implies that the universe cannot be a simulation.
Keywords
- Non-Algorithmic Understanding
- Quantum Gravity
- It from Bit
- Gödel’s incompleteness theorems
- Tarski’s undefinability theorem
- Chaitin’s information-theoretic incompleteness
Main Subjects
References
[1] L. D. Landau and E. M. Lifshitz, “Mechanics”, Butterworth–Heinemann, Oxford, (1976). DOI: https://doi.org/10.1016/C2009-0-25569-3
[2] W. Rindler, “Essential Relativity: Special, General, and Cosmological”, Springer, Berlin, (1977). DOI: https://doi.org/10.1007/978-3-642-86650-0
[3] J. J. Sakurai and J. J. Napolitano, “Modern Quantum Mechanics”, Cambridge University Press, Cambridge, (2017). DOI: https://doi.org/10.1017/9781108499996
[4] M. Srednicki, “Quantum Field Theory”, Cambridge University Press, Cambridge, (2007). DOI: https://doi.org/10.1017/CBO9780511813917
[5] C. M. Wilson, G. Johansson, A. Pourkabirian, M. Simoen, J. R. Johansson, T. Duty, F. Nori, and P. Delsing, “Observation of the dynamical Casimir effect in a superconducting circuit”, Nature 479, 376 (2011). DOI: https://doi.org/10.1038/nature10561
[6] L. C. B. Crispino, A. Higuchi, and G. E. A. Matsas, “The Unruh effect and its applications”, Reviews of Modern Physics 80, 787 (2008). DOI: https://doi.org/10.1103/RevModPhys.80.787
[7] A. Einstein, “Die Feldgleichungen der Gravitation”, Sitzungsberichte der Preussischen Akademie der Wissenschaften zu Berlin (1915). DOI: https://doi.org/10.1007/978-3-322-83770-7_10
[8] B. P. Abbott et al., “Observation of Gravitational Waves from a Binary Black Hole Merger”, Physical Review Letters 116, 061102 (2016). DOI: 10.1103/PhysRevLett.116.061102
[9] R. Penrose, “Gravitational Collapse and Space-Time Singularities”, Physical Review Letters 14, 57 (1965). DOI: 10.1103/PhysRevLett.14.57
[10] S. Hawking and R. Penrose, “The Singularities of Gravitational Collapse and Cosmology”, Proceedings of the Royal Society A 314, 529 (1970). DOI: 10.1098/rspa.1970.0021
[11] V. I. Arnold, “Catastrophe Theory”, Springer Berlin, Heidelberg, (1992). DOI: https://doi.org/10.1007/978-3-642-57884-7_9
[12] M. Berry, “The singularities of light: intensity, phase, polarisation”, Light Sci. Appl. 12, 238 (2023). DOI: https://doi.org/10.1038/s41377-023-01270-8
[13] F. Marino, C. Maitland, D. Vocke, O. Ortolan, and D. Faccio, “Emergent geometries and nonlinear-wave dynamics in photon fluids”, Scientific Reports 6, 23282 (2016). DOI: https://doi.org/10.1038/srep23282
[14] S. L. Braunstein, M. Faizal, L. M. Krauss, F. Marino, and N. A. Shah, “Analogue simulations of quantum gravity with fluids”, Nature Rev. Phys. 5, 612 (2023). DOI: 10.1038/s42254-023-00630-y
[15] M. Bojowald, “Absence of Singularity in Loop Quantum Cosmology”, Physical Review Letters 86, 5227 (2001). DOI: 10.1103/PhysRevLett.86.5227
[16] A. Ashtekar, T. Pawlowski, and P. Singh, “Quantum Nature of the Big Bang: Improved Dynamics”, Phys. Rev. D 74, 084003 (2006). DOI: 10.1103/PhysRevD.74.084003
[17] S. D. Mathur, “The Fuzzball Proposal for Black Holes: An Elementary Review”, Fortschritte der Physik 53, 793 (2005). DOI: 10.1002/prop.200410203
[18] S. D. Mathur, “Tunneling into fuzzball states”, Gen. Rel. Grav. 42, 113 (2010). DOI: 10.1007/s10714-009-0837-3
[19] A. Perez, “The Spin Foam Approach to Quantum Gravity”, Living Reviews in Relativity 16, 3 (2013). DOI: 10.12942/lrr-2013-3
[20] O. Hohm, C. Hull, and B. Zwiebach, “Generalized Metric Formulation of Double Field Theory”, Journal of High Energy Physics 08, 008 (2010). DOI: 10.1007/JHEP08(2010)008
[21] C. M. Hull, “A Geometry for Non-Geometric String Backgrounds”, Journal of High Energy Physics 10, 065 (2005). DOI: 10.1088/1126-6708/2005/10/065
[22] D. Jafferis, A. Zlokapa, J. D. Lykken, D. K. Kolchmeyer, S. I. Davis, N. Lauk, H. Neven, and M. Spiropulu, “Traversable wormhole dynamics on a quantum processor”, Nature 612, 51 (2022). DOI: 10.1038/s41586-022-05424-3
[23] M. Van Raamsdonk, “Spacetime from bits”, Science 370, 198 (2020). DOI: 10.1126/science.aay9560
[24] J. Mäkelä, “Wheeler’s it from bit proposal in loop quantum gravity”, Int. J. Mod. Phys. D 28, 1950129 (2019). DOI: 10.1142/S0218271819501293
[25] J. A. Wheeler, “Information, physics, quantum: The search for links”, in Proceedings III International Symposium on Foundations of Quantum Mechanics, W. J. Archibald, ed., 354 (1989). https://philarchive.org/rec/WHEIPQ
[26] E. Witten, “Noncommutative Geometry and String Field Theory”, Nucl. Phys. B 268, 253 (1986). DOI: 10.1016/0550-3213(86)90155-0
[27] H. Ziaeepour, “Comparing Quantum Gravity Models: String Theory, Loop Quantum Gravity, and Entanglement Gravity versus SU(∞)-QGR”, Symmetry 14, 58 (2022). DOI: 10.3390/sym14010058
[28] M. Faizal, A. Shabir, and A. K. Khan, “Consequences of Gödel theorems on third quantized theories like string field theory and group field theory”, Nucl. Phys. B 1010, 116774 (2025). DOI: 10.1016/j.nuclphysb.2024.116774
[29] L. Bombelli, J. Lee, D. Meyer, and R. D. Sorkin, “Spacetime as a causal set”, Physical Review Letters 59, 521 (1987). DOI: 10.1103/PhysRevLett.59.521
[30] S. Majid, “On the emergence of the structure of Physics”, Phil. Trans. Roy. Soc. Lond. A 376, 0231 (2018). DOI: 10.1098/rsta.2017.0231
[31] G. M. D’Ariano, “Physics Without Physics: The Power of Information-theoretical Principles”, Int. J. Theor. Phys. 56, 97 (2017). DOI: 10.1007/s10773-016-3172-y
[32] X. D. Arsiwalla and J. Gorard, “Pregeometric Spaces from Wolfram Model Rewriting Systems as Homotopy Types”, Int. J. Theor. Phys. 63, 83 (2024). DOI: 10.1007/s10773- 024-05576-0
[33] N. Seiberg, “Emergent spacetime”, in 23rd Solvay Conference in Physics: The Quantum Structure of Space and Time, 1, 163 (2006). DOI: 10.1142/9789812706768_0005 arXiv:hep-th/0601234
[34] J. Polchinski, “String Theory”, Cambridge University Press, (1998). DOI: https://doi.org/10.1017/CBO9780511816079
[35] C. Rovelli, “Quantum Gravity”, Cambridge University Press, Cambridge, UK, (2004). DOI: https://doi.org/10.1017/CBO9780511755804
[36] M. Faizal, “The end of space–time”, Int. J. Mod. Phys. A 38, 2350188 (2023). DOI: 10.1142/S0217751X23501889
[37] M. B. Green, J. H. Schwarz, and E. Witten, “Superstring Theory”, Cambridge University Press, (1987). DOI: https://doi.org/10.1017/CBO9781139248563
[38] T. Thiemann, “Modern Canonical Quantum General Relativity”, Cambridge University Press, (2007). DOI: https://doi.org/10.1017/CBO9780511755682
[39] M. B. Green and J. H. Schwarz, “Anomaly cancellation in supersymmetric d=10 gauge theory”, Physics Letters B 149, 117 (1984). DOI: 10.1016/0370-2693(84)91565-X
[40] A. Ashtekar, “New variables for classical and quantum gravity”, Physical Review Letters 57, 2244 (1986). DOI: https://doi.org/10.1103/PhysRevLett.57.2244
[41] K. Gödel, “Über formal unentscheidbare sätze der principia mathematica und verwandter systeme i”, Monatshefte für Mathematik 38, 173 (1931). DOI: https://doi.org/10.1007/BF01700692
[42] P. Smith, “An Introduction to Gödel’s Theorems”. Cambridge University Press, Cambridge, 2nd ed., (2007). DOI: https://doi.org/10.1017/CBO9781139149105
[43] A. Tarski, “Pojecie Prawdy w Jezykach Nauk Dedukcyjnych (The Concept of Truth in the Languages of the Deductive Sciences)”, Prace Towarzystwa Naukowego Warszawskiego, Wydział III 34 (1933). https://openlibrary.org/books/OL5813583M/ Poje%CC%A8cie_prawdy_w_je%CC%A8zykach_nauk_dedukcyjnych
[44] A. Tarski, “Logic, Semantics, Metamathematics: Papers from 1923 to 1938”. Hackett Publishing Company, Indianapolis, (1983). DOI: http://dx.doi.org/10.2307/2275031
[45] M. Faizal, A. Shabir, and A. K. Khan, “Implications of Tarski’s undefinability theorem on the Theory of Everything”, EPL 148, 39001 (2024). DOI: 10.1209/0295-5075/ad80c2
[46] G. J. Chaitin, “A theory of program size formally identical to information theory”, Journal of the ACM 22, 329 (1975). DOI: 10.1145/321892.321894
[47] G. J. Chaitin, “Meta Math!: The Quest for Omega”, Pantheon Books, New York, (2004). DOI: https://doi.org/10.48550/arXiv.math/0404335
[48] S. Kritchman and R. Raz, “The surprise examination paradox and the second incompleteness theorem”, Notices of the AMS 57, 1454 (2010). DOI: 10.48550/arXiv.1011.4974
[49] J. R. Lucas, “Minds, machines and gödel”, Philosophy 36, 112 (1961). DOI: 10.1017/S0031819100057983
[50] R. Penrose, “Gödel, the mind, and the laws of physics”, in Kurt Gödel’s and the foundations of mathematics: horizons of truth, 339. Cambridge University Press, (2011). DOI: https://doi.org/10.1017/CBO9780511974236.019
[51] R. Penrose, “The nonalgorithmic mind”, Behavioral and Brain Sciences 13, 692 (1990). DOI: 10.1017/s0140525x0008105x
[52] S. Hameroff and R. Penrose, “Consciousness in the universe: A review of the ’orch or’ theory”, Physics of Life Reviews 11, 39 (2014). DOI: 10.1016/j.plrev.2013.08.002
[53] J. P. S., “The lucas–penrose arguments”, in The Argument of Mathematics, p. Chapter 7. Springer, (2023). DOI: 10.1007/978-3-031-64217-3_7
[54] A. Almheiri, T. Hartman, J. Maldacena, E. Shaghoulian, and A. Tajdini, “The entropy of hawking radiation”, Reviews of Modern Physics 93, 035002 (2021). DOI: 10.1103/RevModPhys.93.035002
[55] N. Shiraishi and K. Matsumoto, “Undecidability in quantum thermalization”, Nature Communications 12, 5084 (2021). DOI: 10.1038/s41467-021-25053-0
[56] P. M. Chesler and L. G. Yaffe, “Horizon formation and far-from-equilibrium isotropization in a supersymmetric yang-mills plasma”, Phys. Rev. Lett. 102 211601 (2009). DOI: 10.1103/PhysRevLett.102.211601
[57] S. D. Mathur, “The fuzzball proposal for black holes: An elementary review”, Fortsch. Phys. 53, 793 (2005). DOI: 10.1002/prop.200410203
[58] S. Steinhaus, “Coarse graining spin foam quantum gravity—a review”, Frontiers in Physics 8 (2020). DOI: 10.3389/fphy.2020.00295
[59] T. Cubitt, D. Perez-Garcia, and M. M. Wolf, “Undecidability of the spectral gap”, Forum of Mathematics, Pi 10, 14 (2022). DOI: 10.1017/fmp.2021.15
[60] A. M. Turing, “On computable numbers, with an application to the entscheidungsproblem”, Proceedings of the London Mathematical Society s2-42, 230 (1937). DOI: 10.1112/plms/s2-42.1.230
[61] M. Li and P. Vitányi, “ An Introduction to Kolmogorov Complexity and Its Applications”, Springer, (2019). DOI: 10.1007/978-3-030-11298-1
[62] J. D. Watson, E. Onorati, and T. S. Cubitt, “Uncomputably complex renormalisation group flows”, Nature Communications 13, 7618 (2022). DOI: 10.1038/s41467-022- 35179-4
[63] C. G. Callan, D. Friedan, E. J. Martinec, and M. J. Perry, “Strings in background fields”, Nucl. Phys. B 262, 593 (1985). DOI: 10.1016/0550-3213(85)90506-1
[64] S. Steinhaus and J. Thürigen, “Emergence of spacetime in a restricted spin-foam model”, Phys. Rev. D 98, 026013 (2018). DOI: 10.1103/PhysRevD.98.026013
[65] D. Litim, “Fixed points of quantum gravity”, Phys. Rev. Lett. 92, 201301 (2004). DOI: 10.1103/PhysRevLett.92.201301
[66] J. Ambjørn, J. Jurkiewicz, and R. Loll, “The spectral dimension of the universe is scale dependent”, Phys. Rev. Lett. 95, 171301 (2005). DOI: 10.1103/PhysRevLett.95.171301
[67] P. Hayden, S. Nezami, X.-L. Qi, N. Thomas, M. Walter, and Z. Yang, “Holographic duality from random tensor networks”, Journal of High Energy Physics 2016, 009 (2016). DOI: 10.1007/JHEP11(2016)009
[68] B. Dittrich, F. C. Eckert, and M. Martin-Benito, “Coarse graining methods for spin net and spin foam models”, New J. Phys. 14, 035008 (2012). DOI: 10.1088/1367- 2630/14/3/035008
[69] M. Kliesch, D. Gross, and J. Eisert, “Matrix-product operators and states: Np-hardness and undecidability”, Physical Review Letters 113, 160503 (2014). DOI: 10.1103/PhysRevLett.113.160503
[70] Y. Tachikawa, “Undecidable problems in quantum field theory”, International Journal of Theoretical Physics 62, 199 (2023). DOI: 10.1007/s10773-023-05357-1
[71] J. Bausch, T. S. Cubitt, and J. D. Watson, “Uncomputability of phase diagrams”, Nature Communications 12, 452 (2021). DOI: 10.1038/s41467-020-20504-6
[72] A. Feller and E. R. Livine, “Ising spin network states for loop quantum gravity: A toy model for phase transitions”, Class. Quant. Grav. 33, 065005 (2016). DOI: 10.1088/0264-9381/33/6/065005
[73] F. Amijee, “Principle of suffcient reason”, in Encyclopedia of Early Modern Philosophy and the Sciences, D. Jalobeanu and C. T. Wolfe, eds. Springer, (2021). DOI: 10.1007/978-3-319-20791-9_593-1
[74] G. W. Leibniz, “Discourse on Metaphysics”, Hackett Publishing Company, Indianapolis, (1996). A seminal work where Leibniz famously asserts that ”nothing happens without a reason”. https://www.earlymoderntexts.com/assets/pdfs/leibniz1686d.pdf.
[75] C. H. Bennett, “Undecidable dynamics”, Nature 346, 606 (1990). DOI: 10.1038/346606a0
[76] I. Stewart, “Deciding the undecidable”, Nature 352, 664 (1991). DOI: 10.1038/352664a0
[77] J. L. Friedman, M. S. Morris, I. D. Novikov, F. Echeverria, G. Klinkhammer, K. S. Thorne, and U. Yurtsever, “Cauchy problem in spacetimes with closed timelike curves”, Physical Review D 42, 1915 (1990). DOI: 10.1103/PhysRevD.42.1915
[78] I. D. Novikov, “Time machine and self-consistent evolution in problems with selfinteraction”, Phys. Rev. D 45 (1992). DOI: https://doi.org/10.1103/PhysRevD.45.1989
[79] M. Van den Nest and H. J. Briegel, “Measurement-based quantum computation and undecidable logic”, Foundations of Physics 38, 448 (2008). DOI: 10.1007/s10701-008- 9212-6
[80] S. Lloyd, “Quantum-mechanical computers and uncomputability”, Physical Review Letters 71, 943 (1993). DOI: 10.1103/PhysRevLett.71.943
[81] R. Penrose, “On gravity’s role in quantum state reduction”, General Relativity and Gravitation 28, 581 (1996). DOI: 10.1007/BF02105068
[82] L. Diósi, “A universal master equation for the gravitational violation of quantum mechanics”, Physics Letters A 120, 377 (1987). DOI: https://doi.org/10.1016/0375- 9601(87)90681-5
[83] J. L. Gaona-Reyes, L. Menéndez-Pidal, M. Faizal, and M. Carlesso, “Spontaneous collapse models lead to the emergence of classicality of the Universe”, JHEP 02, 193 (2024). DOI: https://doi.org/10.1007/JHEP02(2024)193
[84] Álvaro Perales-Eceiza, T. Cubitt, M. Gu, D. Pérez-García, and M. M. Wolf, “Undecidability in physics: a review”, (2024). https://arxiv.org/abs/2410.16532
[85] N. Bostrom, “Are we living in a computer simulation?”, Philosophical Quarterly 53, 243 (2003). DOI: 10.1111/1467-9213.00309
[86] S. Guttenplan, “David J. Chalmers, Reality+: Virtual Worlds and the Problems of Philosophy”, 60. (2023). DOI: 10.1007/s12115-023-00832-1
[87] D. Deutsch, “The Fabric of Reality”, Penguin, London, (1997). https://www. daviddeutsch.org.uk/books/the-fabric-of-reality/.
History
- Receive Date: 06 June 2025
- Revise Date: 18 June 2025
- Accept Date: 17 June 2025
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