Multiverses, Science, and Ultimate Causation

  • George Ellis
Part of the Astrophysics and Space Science Library book series (ASSL, volume 395)


This chapter the motivation and evidence for the various types of multiverses that have been proposed. A key problem is their lack of testability, because of the existence of cosmic horizons; nevertheless they are claimed to be a scientific hypothesis. I review the arguments in their favour, and suggest none is conclusive, although there is one case where they could be disproved (the small universe case) and one that would indeed be quite convincing circumstantial evidence (circles in the CMB sky associated with variation of fundamental constants).

Multiverse proponents are in fact proposing weakening the criteria for a scientific theory, which is a dangerous tactic. The scientific status of these proposals is particularly brought in to question by various claims of physically existing infinities, which cannot possibly be verified. Finally I comment that multiverses do not solve issues of ultimate causation, as claimed by their proponents. If one wants to investigate this issue, one must extend the kind of data one considers beyond data obtainable from physics experiments and astronomical observations, to include broader areas of human experience, that are also evidence on the nature of the universe.


Wilkinson Microwave Anisotropy Probe Loop Quantum Cosmology Observable Universe Bubble Collision Chaotic Inflation 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


  1. Aguirre, A., & Johnson, M. C. (2009). A status report on the observability of cosmic bubble collisions. Reports on Progress in Physics, 74, 074901 [arXiv:0908.4105v2].ADSCrossRefGoogle Scholar
  2. Balashov, Y. Y. (1991). Resource letter AP-1 the anthropic principle. American Journal of Physics, 54, 1069.MathSciNetADSCrossRefGoogle Scholar
  3. Barrow, J. D. (2005). General cosmological bounds on spatial variations of physical constants. Physical Review D, 71, 083520.ADSCrossRefGoogle Scholar
  4. Barrow, J. D., & Tipler, F. J. (1986). The anthropic cosmological principle. Oxford: Oxford University Press.Google Scholar
  5. Bjorken, J. D. (2004). The classification of universes. Astro-ph/0404233. SLAC-PUB-10276.Google Scholar
  6. Bondi, H. (1960). Cosmology. Cambridge: Cambridge University Press.zbMATHGoogle Scholar
  7. Bostrom, N. (2003). Are you living in a computer simulation? The Philosophical Quarterly, 53, 243–255.CrossRefGoogle Scholar
  8. Carr, B. (Ed.). (2009). Universe or multiverse? Cambridge: Cambridge University Press.Google Scholar
  9. Cornish, N. J., Spergel, D. N., & Starkman, G. D. (1998). Circles in the sky: Finding topology with the microwave background radiation. Classical Quantum Gravity, 15, 2657–2670 [arXiv:gr-qc/9602039].MathSciNetADSCrossRefzbMATHGoogle Scholar
  10. Davies, P. C. W. (2004). Multiverse cosmological models. Modern Physics Letters A, 19, 727.MathSciNetADSCrossRefGoogle Scholar
  11. Dawkins, R. (2006). The god delusion. Boston: Houghton Mifflin.Google Scholar
  12. Deutsch, D. (1997). The fabric of reality: The science of parallel universes. New York: Allen Lane.Google Scholar
  13. Ellis, G. F. R. (1975). Cosmology and verifiability. Quarterly Journal of the Royal Astronomical Society, 16, 245.ADSGoogle Scholar
  14. Ellis, G. F. R. (2006). Issues in the philosophy of cosmology. In J. Butterfield & J. Earman (Eds.), Handbook in philosophy of physics (pp. 1183–1285). Amsterdam: Elsevier [].
  15. Ellis, G. F. R. (2011). Why are the laws of nature as they are? What underlies their existence? In D. York, O. Gingerich, & S.-N. Zhang (Eds.), The astronomy revolution: 400 years of exploring the cosmos (pp. 385–404). Boca Raton: Taylor and Francis.Google Scholar
  16. Ellis, G. F. R., Kirchner, U., & Stoeger, W. R. (2003). Multiverses and physical cosmology. Monthly Notices of the Royal Astronomical Society, 347, 921.ADSCrossRefGoogle Scholar
  17. Ellis, G. F. R., & Schreiber, G. (1986). Observational and dynamic properties of small universes. Physics Letters A, 115, 97.MathSciNetADSCrossRefGoogle Scholar
  18. Ellis, G. F. R., & Stoeger, W. J. (1988). Horizons in inflationary universes. Classical and Quantum Gravity, 207.Google Scholar
  19. Feeney, S. M., Johnson, M. C., Mortlock, D. J., & Peiris, H. V. (2011). First observational tests of eternal inflation. Physical Review Letters, 107(7), 071301 [arXiv:1012.1995v3]. Phys. Rev. Lett. 107, 071301 (2011)ADSCrossRefGoogle Scholar
  20. Freivogel, B., Kleban, M., Martinez, M. R., & Susskind, L. (2006). Observational consequences of a landscape. Journal of High Energy Physics, 0603, 039 [arXiv:hep-th/0505232].ADSCrossRefGoogle Scholar
  21. Gedalia, O., Jenkins, A., & Perez, G. (2011). Why do we observe a weak force? The hierarchy problem in the multiverse. Physical Review, D83, 115020 [arXiv:1010.2626v3].ADSGoogle Scholar
  22. Greene, B. (2011). The hidden reality: Parallel universes and the deep laws of the cosmos. New York: Knopff.zbMATHGoogle Scholar
  23. Gurzadyan, V.G.,& Penrose R. (2011a). Concentric circles in WMAP data may provide evidence of violent pre-Big-Bang activity. [arXiv:1011.3706].Google Scholar
  24. Gurzadyan, V. G., & Penrose R. (2011b). CCC-predicted low-variance circles in CMB sky and LCDM. [arXiv:1104.5675].Google Scholar
  25. Guth, A. H. (2001). Eternal Inflation. astro-ph/0101507. Report MIT-CTP-3007.Google Scholar
  26. Hartle, J. (2004). Anthropic reasoning and quantum cosmology. New York: American Institute of Physics. gr-qc/0406104.Google Scholar
  27. Hilbert, D. (1964). On the infinite. In P. Benacerraf & H. Putnam (Eds.), Philosophy of mathematics (p. 134). Englewood Cliff: Prentice Hall.Google Scholar
  28. Kachru, S., Kallosh, R., Linde, A., & Trivedi, S. P. (2003). de Sitter Vacua in string theory. Physical Review, D68, 046005 [arXiv:hep-th/0301240v2].MathSciNetADSGoogle Scholar
  29. Katz, G., & Weeks, J. (2004). Polynomial interpretation of multipole vectors. Physical Review D, 70, 063527. astro-ph/0405631. Phys.Rev. D70 (2004) 063527ADSCrossRefGoogle Scholar
  30. Kleban, M. (2011). Cosmic bubble collisions. London: Institute of Physics [arXiv:1107.2593v1].Google Scholar
  31. Lachieze-Ray, M., & Luminet, J. P. (1995). Cosmic topology. Physics Reports, 254, 135.MathSciNetADSCrossRefGoogle Scholar
  32. Leslie, J. (1996). Universes. London: Routledge.Google Scholar
  33. Lewis, D. K. (2000). On the plurality of worlds. Oxford: Blackwell.Google Scholar
  34. Linde, A. D. (1983). Chaotic inflation. Physics Letters, B129, 177.MathSciNetADSGoogle Scholar
  35. Linde, A. D. (1990). Particle physics and inflationary cosmology. Chur: Harwood Academic Publishers.Google Scholar
  36. Linde, A. D. (2003). Inflation, quantum cosmology and the anthropic principle. In J. D. Barrow (Ed.), Science and ultimate reality: From quantum to cosmos. Cambridge: Cambridge University Press.Google Scholar
  37. Linde, A. D., Linde, D. A., & Mezhlumian, A. (1994). From the big bang theory to the theory of a stationary universe. Physical Review D, 49, 1783.ADSCrossRefGoogle Scholar
  38. Linde, A., & Noorbala, M. (2010). Measure problem for eternal and non-eternal inflation. arXiv:1006.2170.Google Scholar
  39. Luminet, J. P., Weeks, J. R., Riazuelo, A., Lehoucq, R., & Uzan, J.-P. (2003) “Dodecahedral space topology as an explanation for weak wide-angle temperature correlations in the cosmic microwave background” Nature. 425:593L.Google Scholar
  40. Moss, A., Scott, D., & Zibin, J. P. (2010). No evidence for anomalously low variance circles on the sky. [arXiv:1012.1305v3].Google Scholar
  41. Murphy, N., & Ellis, G. F. R. (1996). On the moral nature of the universe: Cosmology, theology, and ethics. Minneapolis: Fortress Press.Google Scholar
  42. Nelson, W., & Wilson-Ewing, E. (2011). Pre-Big-Bang cosmology and circles in the cosmic microwave background. [arXiv:1104.3688v2] Phys.Rev.D84:043508,2011.Google Scholar
  43. Olive, K. A., Peloso, M., & Uzan, J.-P. (2011). The wall of fundamental constants. Physical Review, D83, 043509 [arXiv:1011.1504v1].ADSGoogle Scholar
  44. Penrose, R. (2010). Cycles of time: An extraordinary new view of the universe. London: The Bodley Head.zbMATHGoogle Scholar
  45. Rees, M. J. (1999). Just six numbers: The deep forces that shape the universe. London: Weidenfeld and Nicholson.Google Scholar
  46. Rees, M. J. (2001). Our cosmic habitat. Princeton: Princeton University Press.Google Scholar
  47. Rees, M. J. (2003). Numerical coincidences and ‘tuning’ in cosmology. In C. Wickramasinghe (Ed.), Fred hoyle’s universe (p. 95). Dordrecht: Kluwer.Google Scholar
  48. Rothman, T., & Ellis, G. F. R. (1992). Smolin’s natural selection hypothesis. Quartely Journal rof the Royal Astronomical Society, 34, 201.ADSGoogle Scholar
  49. Sciama, D. W. (1993). Is the universe unique? In G. Borner & J. Ehlers (Eds.), Die Kosmologie der Gegenwart. München: Serie Piper.Google Scholar
  50. Shaw, D. J., & Barrow, J. D. (2007). Observable effects of scalar fields and varying constants. General Relativity and Gravitation, 39, 1235–1257.MathSciNetADSCrossRefzbMATHGoogle Scholar
  51. Smolin, L. (1997). The life of the cosmos. New York: Oxford University Press.zbMATHGoogle Scholar
  52. Starobinsky, A. A. (1986). Current trends in field theory, quantum gravity and strings. In Lecture notes in physics (Vol. 246, p. 107). Heidelberg: Springer.Google Scholar
  53. Steinhardt, P. J., & Turok, N. (2002). A cyclic model of the universe. Science, 296, 1436.MathSciNetADSCrossRefzbMATHGoogle Scholar
  54. Susskind, L. (2003). The anthropic landscape of string theory. hep-th/0302219.Google Scholar
  55. Susskind, L. (2006). The cosmic landscape: String theory and the illusion of intelligent design. New York: Back Bay Books.Google Scholar
  56. Tegmark, M. (1998). Is the theory of everything merely the ultimate ensemble theory? Annals of Physics, 270, 1.MathSciNetADSCrossRefzbMATHGoogle Scholar
  57. Tegmark, M. (2004). Parallel universes. In J. D. Barrow (Ed.), Science and ultimate reality: From quantum to cosmos. Cambridge: Cambridge University Press [astro-ph/0302131].Google Scholar
  58. Tod, P. (2011). Penrose’s circles in the CMB and a test of inflation [arXiv:1107.1421v1].Google Scholar
  59. Uzan, J-P. (2010). Varying constants, gravitation and cosmology [arXiv:1009.5514v1]. Living Reviews in RelativityGoogle Scholar
  60. Vilenkin, A. (1983). The birth of inflationary universes. Physical Review, D27, 2848.MathSciNetADSGoogle Scholar
  61. Vilenkin, A. (1995). Predictions from quantum cosmology. Physical Review Letters, 74, 846.ADSCrossRefGoogle Scholar
  62. Vilenkin, A. (2007). Many worlds in one: The search for other universes. New York: Hill and Wang.Google Scholar
  63. Webb, J. K., King, J. A., Murphy, M. T., Flambaum, V. V., Carswell, R. F., & Bainbridge, M. B. (2008). Evidence for spatial variation of the fine structure constant [arXiv:1008.3907v1]. Phys. Rev. Lett., 107, 191101, 2011Google Scholar
  64. Weinberg, S. W. (1972). Gravitation and cosmology. New York: Wiley.Google Scholar
  65. Weinberg, S. W. (2000a). The cosmological constant problems. astro-ph/0005265. Report UTTG-07-00Google Scholar
  66. Weinberg, S. W. (2000b). A priori probability distribution of the cosmological constant. Physical Review D, 61, 103505.MathSciNetADSCrossRefGoogle Scholar
  67. Yamauchi, D., Linde, A., Naruko, A., Sasaki, M., & Tanaka, T. (2011). Open inflation in the landscape. arXiv:1105.2674v2. Phys.Rev.D84:043513,2011Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  1. 1.Department of Mathematics and Applied MathematicsUniversity of Cape TownRondeboschSouth Africa

Personalised recommendations