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  • Cited by 8
  • Print publication year: 2007
  • Online publication date: July 2014

20 - Scientific alternatives to the anthropic principle

Summary

Introduction

I have chosen a deliberately provocative title, in order to communicate a sense of frustration I have felt for many years about how otherwise sensible people, some of whom are among the scientists I most respect and admire, espouse an approach to cosmological problems — the Anthropic Principle (AP) — that is easily seen to be unscientific. By calling it unscientific I mean something very specific, which is that it lacks a property necessary for any scientific hypothesis — that it be falsifiable. According to Popper [1—4], a theory is falsifiable if one can derive from it unambiguous predictions for practical experiments, such that — were contrary results seen — at least one premise of the theory would have been proven not to true. This introduction will outline my argument in a few paragraphs. I will then develop the points in detail in subsequent sections.

While the notion of falsifiability has been challenged and qualified by philosophers since Popper, such as Kuhn, Feyerabend and others, few philosophers of science or working scientists would be able to take seriously a fundamental theory of physics that had no possibility of being disproved by an experiment. This point is so basic to how science works that it is perhaps worthwhile taking a moment to review its rationale.

[1] K., Popper. Conjectures and Refutations (London: Routledge and Keagan Paul, 1963), pp. 33–39.
[2] K., Popper. In Readings in the Philosophy of Science, ed. T., Schick (Mountain View, CA: Mayfield Publishing Company, 2000), pp. 9–13.
[3] K., Popper. The Open Society and its Enemies (Princeton, NJ: Princeton University Press, 1971).
[4] K., Popper. The Logic of Scientific Discovery (London: Routledge, 1992).
[5] L., Smolin. The Trouble with Physics (Boston, MA: Houghton Mifflin, 2006).
[6] B. J., Carr and M. J., Rees. The anthropic principle and the structure of the physical world. Nature 278 (1979), 605.
[7] B., Carter. The significance of numerical coincidences in nature. Cambridge University preprint (1967).
[8] B., Carter. Number coincidences and the anthropic principle in cosmology. In Confrontation of Cosmological Theories with Observational Data, IAU Symposium No. 63, ed. M., Longair (Dordrecht: Reidel, 1974), p. 291.
[9] J. D., Barrow and F. J., TiplerThe Anthropic Cosmological Principle (Oxford: Oxford University Press, 1986).
[10] S., Roush. Copernicus, Kant, and the anthropic cosmological principles. Stud. Hist. Phil. Mod. Phys. 34 (2003), 5–35.
[11] S., Roush. Anthropic principle. In The Philosophy of Science: An Encyclopedia, eds. J., Pfeifer and S., Sarkar (London: Routledge, 2003).
[12] A., Feoli and S., Rampone. Is the strong anthropic principle too weak?Nuovo Cim. B 114 (1999), 281.
[13] L., Smolin. Did the universe evolve?Class. Quant. Grav. 9 (1992), 173.
[14] L., Smolin (1994) On the fate of black hole singularities and the parameters of the standard model. [gr-qc/9404011].
[15] L., Smolin. Cosmology as a problem in critical phenomena. In Proceedings of the Guanajuato Conference on Complex Systems and Binary Networks, eds. R., Lopez-Pena, R., Capovilla, R., Garcia-Pelayo, H., Waalebroeck and F., ertuche (Berlin: Springer, 1995) [gr-qc/9505022].
[16] L., Smolin. Experimental signatures of quantum gravity. In Proceedings of the Fourth Drexel Conference on Quantum Nonintegrability, eds. B. L., Hu and D. H., Feng (Boston: International Publishers, 1996) [gr-qc/9503027].
[17] L., Smolin. The Life of the Cosmos (New York: Oxford University Press, 1997).
[18] P., Binetruy, G. L., Kane, B. D., Nelson, L-T., Wang and T. T., Wang. Relating incomplete data and incomplete theory. Phys. Rev. D 70 (2004), 095006 [hep-ph/0312248].
[19] F., Markopoulou. Towards gravity from the quantum (2006) [hep-th/0604120].
[20] D. W., Kribs and F., Markopoulou. Geometry from quantum particles (2005) [gr-qc/0510052].
[21] S. O., Bilson-Thompson, F., Markopoulou and L., Smolin. Quantum gravity and the standard model (2006) [hep-th/0603022].
[22] S.O., Bilson-Thompson. A topological model of composite preons. (2005) [hep-ph/0503213].
[23] T., Thiemann. The LQG – string:loop quantum gravity quantization of string theory I. Flat target space. Class. Quant. Grav. 23 (2006), 1923 [hep-th/0401172].
[24] L., Smolin. How far are we from the quantum theory of gravity? (2003) [hep-th/0303185].
[25] S., Kachru, R., Kallosh, A., Linde and S. P., Trivedi. de Sitter vacua in string theory. Phys. Rev. D 68 (2003), 046005 [hep-th/0301240].
[26] S. B., Giddings, S., Kachru and J., Polchinski. Hierarchies from fluxes in string compactifications. Phys. Rev. D 66 (2002), 106006 [hep-th/0105097].
[27] R., Bousso and J., Polchinski. Quantization of four-form fluxes and dynamical neutralization of the cosmological constant. JHEP, 0006 (2000), 006 [hep-th/0004134].
[28] L., Susskind. This volume (2007) [hep-th/0302219].
[29] M., Douglas. The statistics of string/M theory vacua. JHEP, 0305 (2003), 046 [hep-th/0303194].
[30] M., Douglas. Statistical analysis of the supersymmetry breaking scale (2004) [hep-th/0405279].
[31] A. H., Guth. The inflationary universe: A possible solution to the horizon and flatness problems. Phys. Rev. D 23 (1981), 347.
[32] A. D., Linde. A new inflationary universe scenario: A possible solution of the horizon, flatness, homogeneity, isotropy and primordial monopole problems. Phys. Lett. B 108 (1982), 389.
[33] A., Albrecht and P. J., Steinhardt. Cosmology for grand unified theories with radiatively induced symmetry breaking. Phys. Rev. Lett. 48 (1982), 1220.
[34] A. D., Linde. Particle Physics and Inflatioary Cosmology (Chur, Switzerland: Harwood Academic, 1990).
[35] P. J., Steinhardt and N., Turok. A cyclic model of the universe. Science, 296 (2002), 1436.
[36] P. J., Steinhardt and N., Turok. Cosmic evolution in a cyclic universe. Phys. Rev. D 65 (2002), 126003 [hep-th/0111098].
[37] J. W., Moffat. Superluminary universe: A possible solution to the initial value problem in cosmology. Int. J. Mod. Phys. D 2 (1993), 351 [gr-qc/9211020].
[38] A., Albrecht and J., Magueijo. A time varying speed of light as a solution to cosmological puzzles. Phys. Rev. D 59 (1999), 043516 [astro-ph/9811018].
[39] J. D., Barrow. Cosmologies with varying light speed. Phys. Rev. D 59 (1999), 043515.
[40] J., Magueijo. New varying speed of light theories. Rep. Prog. Phys. 66 (2003), 2025 [astro-ph/0305457].
[41] A., Vilenkin. The birth of inflationary universes. Phys. Rev. D 27 (1983), 2848.
[42] A., Linde. The inflationary universe. Rep. Prog. Phys. 47 (1984), 925.
[43] A., Linde, D., Linde and A., Mezhlumian. From the big bang theory to the theory of a stationary universe. Phys. Rev. D 49 (1994), 1783 [gr-qc/9306035].
[44] J., Garcia-Bellido and A., Linde. Stationarity of inflation and predictions of quantum cosmology. Phys. Rev. D 51 (1995), 429 [hep-th/9408023].
[45] J., Garriga and A., Vilenkin. A prescription for probabilities in eternal inflation. Phys. Rev. D 64 (2001), 023507 [gr-qc/0102090].
[46] J. A., Wheeler. Beyond the end of time. In Black Holes, Gravitational Waves and Cosmology: An Introduction to Current Research, eds. M., Rees, R., Ruffini and J.A., Wheeler (New York: Gordon and Breach).
[47] C., Misner, K., Thorne and J. A., Wheeler. Gravitation (San Francisco: Freeman, 1974).
[48] V. P., Frolov, M. A., Markov and M. A., Mukhanov. Through a black hole into a new universe?Phys. Lett. B 216 (1989), 272.
[49] A., Lawrence and E., Martinec. String field theory in curved space-time and the resolution of spacelike singularities. Class. Quant. Grav. 13 (1996), 63 [hep-th/9509149].
[50] E., Martinec. Spacelike singularities in string theory. Class. Quant. Grav. 12 (1995), 941 [hep-th/9412074].
[51] M., Bojowald. Isotropic loop quantum cosmology. Class. Quant. Grav. 19 (2002), 2717 [gr-qc/0202077].
[52] M., Bojowald. Inflation from quantum geometry. Phys. Rev. Lett. 89 (2002), 261301 [gr-qc/0206054].
[53] M., Bojowald. The semi-classical limit of loop quantum cosmology. Class. Quant. Grav. 18 (2001), L109 [gr-qc/0105113].
[54] M., Bojowald. Dynamical initial conditions in quantum cosmology. Phys. Rev. Lett. 87 (2001), 121301 [gr-qc/0104072].
[55] S., Tsujikawa, P., Singh and R., Maartens. Loop quantum gravity effects on inflation and the CMB. Class. Quant. Grav. 21 (2003), 5767 [astro-ph/0311015].
[56] V., Husain and O., Winkler. Quantum resolution of black hole singularities. Class. Quant. Grav. 22 (2005), L127 [gr-qc/0410125].
[57] L., Modesto. Disappearance of black hole singularity in quantum gravity. Phys. Rev. D 70 (2004), 124009 [gr-qc/0407097].
[58] A., Ashtekar and M., Bojowald. Quantum geometry and the Schwarzschild singularity. Class. Quant. Grav. 23 (2006), 391 [gr-qc/0509075].
[59] R. H., Dicke. Principle of equivalence and weak interactions. Rev. Mod. Phys. 29 (1957), 355.
[60] P. A. M., Dirac. The cosmological constants. Nature, 139 (1937), 323.
[61] F., Hoyle. On the fragmentaion of gas clouds into galaxies and stars. Astrophys. J. 118 (1953), 513.
[62] A., Vilenkin. Predictions from quantum cosmology. Phys. Rev. Lett. 74 (1995), 846 [gr-qc/9406010].
[63] J., Garriga and A., Vilenkin. Testable anthropic predictions for dark energy. Phys. Rev. D 67 (2003), 043503 [astro-ph/0210358].
[64] J., Garriga, M., Livio and A., Vilenkin. The cosmological constant and the time of its dominance. Phys. Rev. D 61 (2000), 023503 [astro-ph/9906210].
[65] S., Weinberg. Anthropic bound on the cosmological constant. Phys. Rev. Lett. 59 (1987), 2067.
[66] H., Martel, P., Shapiro and S., Weinberg. Likely values of the cosmological constant. Astrophys. J. 492 (1998), 29 [astro-ph/9701099].
[67] S., Weinberg. A priori probability distribution of the cosmological constant. Phys. Rev. D 61 (2000), 103505 [astro-ph/0002387].
[68] S., Weinberg. The cosmological constant problems. In Sources and Detection of Dark Matter and Dark Energy in the Universe, ed. D., Cline (New York: Springer-Verlag, 2000) [astro-ph/0005265].
[69] H., Nielsen. Random dynamics and relations between the number of fermion generations and the fine structure constants. Act. Phys. Polon. B 20 (1989), 427.
[70] J. R., Gott III. Implications of the Copernican principle for our future prospects. Nature, 363 (1993), 315.
[71] J., Leslie. The End of the World. The Ethics and Science of Human Extinction (London: Routledge, 1996).
[72] F., Markopoulou. The internal description of a causal set: What the universe looks like from the inside. Commun. Math. Phys. 211 (2000), 559 [gr-qc/9811053].
[73] M., Ahmed, S., Dodelson, P. B., Greene and R., Sorkin. Ever-present lambda. Phys. Rev. D 69 (2004), 103523 [astro-ph/0209274].
[74] M. J., Rees. Anthropic reasoning. Clues to a fundamental theory. Complexity, 3 (1997), 17.
[75] M. J., Rees. Numerical coincidences and ‘tuning’ in cosmology. In Fred Hoyle's Universe, eds. C., Wickramasinghe, G., Burbidge and J. V., Narlikar (Dordrecht: Kluwer, 2003), p. 87.
[76] M., Tegmark and M. J., Rees. Why is the CMB fluctuation level 10−5?Astrophys. J. 499 (1998), 526 [astro-ph/9709058].
[77] M. L., Graesser, S. D. H., Hsu, A., Jenkins and M. B., Wise. Anthropic distribution for cosmological constant and primordial density perturbations. Phys. Lett. B 600 (2004), 15 [hep-th/0407174].
[78] A., Aguirre. The cold big-bang cosmology as a counter-example to several anthropic arguments. Phys. Rev. D 64 (2001), 083508 [astro-ph/0106143].
[79] P., Davies. The Mind of God (New York: Simon and Schuster, 1991).
[80] J., Gribbin. In the Beginning: After COBE and Before the Big Bang (New York: Little Brown, 1993).
[81] S., Kauffman. Investigations into Autonomous Agents (Oxford: Oxford University Press, 2002).
[82] Y., Nambu. Distribution of particle physics. Prog. Theor. Phys. Suppl. 85 (1985), 104.
[83] A., Linde. Particle physics and inflationary cosmology. Phys. Today, 40 (1987), 61.
[84] A., Linde. Particle Physics and Inflationary Cosmology (Chur, Switzerland: Harwood, 1990).
[85] A., Linde. Universe multiplication and the cosmological constant problem. Phys. Lett. B 200 (1988), 272.
[86] A., Linde. Life after inflation and the cosmological constant problem. Phys. Lett. B 227 (1989), 352.
[87] A., Linde. Extended chaotic inflation and spatial variations of the gravitational constant. Phys. Lett. B 238 (1990), 1680.
[88] J., Garcia-Bellido, A., Linde and D., Linde. Fluctuations of the gravitational constant in the inflationary Brans-Dicke cosmology. Phys. Rev. D 50 (1994), 730 [astro-py/9312039].
[89] J., Garcia-Bellido and A., Linde. Stationary solutions in Brans-Dicke stochastic inflationary cosmology. Phys. Rev. D 52 (1995), 6780 [gr-qc/9504022].
[90] R., Gambini and J., Pullin. Discrete quantum gravity: A mechanism for selecting the value of fundamental constants. Int. J. Mod. Phys. D 12 (2003), 1775 [gr-qc/0306095].
[91] T., Rothman and G. F. R., Ellis. Smolin's natural selection hypothesis. Quart. J. Roy. Astron. Soc. 34 (1993), 201.
[92] E. R., Harrison. The natural selection of universes containing intelligent life. Quart. J. Roy. Astron. Soc. 36 (1995), 193.
[93] J., Silk. Science, 227 (1997), 644.
[94] M., Rees. In Before the Beginning (Reading, MA: Addison Wesley, 1997).
[95] G. E., Brown and H. A., Bethe. A scenario for a large number of low-mass black holes in the Galaxy. Astrophys. J. 423 (1994), 659.
[96] G. E., Brown and J. C., Weingartner. Accretion onto and radiation from the compact object formed in SN 1987A. Astrophys. J. 436 (1994), 843.
[97] G. E., Brown. Kaon condensation in dense matter. Nucl. Phys. A 574 (1994), 217.
[98] H. A., Bethe and G. E., Brown. Observational constraints on the maximum neutron star mass. Astrophys. J. Lett. 445 (1995), L129.
[99] G. B., Cook, S. L., Shapiro and S.A., Teukolsky. Rapidly rotating neutron stars in general relativity. Realistic equations of state. Astrophys. J. 424 (1994), 823.
[100] S. E., Thorsett, Z., Arzoumanian, M. M., McKinnon and J. H., Taylor. The masses of two binary neutron star systems. Astrophys. J. Lett. 405 (1993), L29.
[101] D. J., Nice, R. W., Sayer and J. H., Taylor. PSR J1518+4904: A mildly relativistic binary pulsar system. Astrophys. J. 466 (1996), L87.
[102] J., Casares, P., Charles and E., Kuulkers. The mass of the neutron star in Cyg X-2 (V1341 Cyg). Astrophys. J. Lett. 493 (1997), L39.
[103] B. J., Carr, J. H., Gilbert and J. E., Lidsey. Black hole relics from inflation: Limits on blue perturbation spectra. Phys. Rev. D 50 (1994), 4853.
[104] M., Bucher, A. S., Goldhaber and N., Turok. An open universe from inflation. Phys. Rev. D 52 (1995), 3314–3337 [hep-ph/9411206, PUPT-94-1507].
[105] M., Bucher and N., Turok. Open inflation with arbitrary false vacuum mass. Phys. Rev. D 52 (1995), 5538–5548 [hep-ph 9503393, PUPT-95-1518].
[106] J. R., Gott. Creation of open universes from de Sitter space. Nature, 295 (1982), 304.
[107] J., Garcia-Bellido and A., Linde. Tilted hybrid inflation. Phys. Lett. B 398 (1997), 18 [astro-ph/9612141].
[108] J., Garcia-Bellido and A., Linde. Open hybrid inflation. Phys. Rev. D 55 (1997), 7480–7488 [astro-ph/9701173].
[109] D. H., Lyth and A., Riotto. Particle physics models of inflation and the cosmological density perturbation. Phys. Rep. 314 (1999), 1 [hep-ph/9807278].
[110] M., Tegmark, J., Silk, M., Rees, A., Blanchard, T., Abel and F., Palla. How small were the first cosmological objects?Astrophys. J. 474 (1997), 1 [astro-ph/9603007].