Cosmological natural selection (fecund universes)
Cosmological natural selection (CNS), also known as fecund universes, is a prominent theory of universe evolution, development and reproduction originally proposed by eminent theoretical physicist and quantum gravity scholar Lee Smolin in 1992.
Universe reproduction via black holes
According to CNS, black holes may be mechanisms of universe reproduction within the multiverse, an extended cosmological environment in which universes grow, die, and reproduce. Rather than a ‘dead’ singularity at the center of black holes, a point where energy and space go to extremely high densities, what occurs in Smolin’s theory is a 'bounce' that produces a new universe with parameters stochastically different from the parent universe. Smolin theorizes that these descendant universes will be likely to have similar fundamental physical parameters to the parent universe (such as the fine structure constant, the proton to electron mass ratio and others) but that these parameters, and perhaps to some degree the laws that derive from them, will be slightly altered in some stochastic fashion during the replication process. Each universe therefore potentially gives rise to as many new universes as it has black holes.
In a process analogous to Darwinian natural selection, those universes best able to reproduce and adapt would be expected to predominate in the multiverse. As with biological natural selection, mechanisms for reproduction, variation, and the phenotypic effects of alternate parameter heritability may be modeled. With respect to adaptation, selection for a range of proposed universal fitness functions (black hole fecundity, universal complexity, etc.) may be tentatively tested with respect to present physical theory, by exploring the features with respect to these functions of the ensemble of possible universes that are adjacent to our universe in parameter space. Nevertheless, strategies for validating the appropriateness of fitness functions remain unclear at present, as do any hypotheses of adaptation with respect to the multiverse, other universes, or other black holes.
Smolin states that CNS originated as an attempt to explore the fine-tuning problem in cosmology via an alternative landscape theory to string theory, one that might provide more readily falsifiable predictions. According to The Life of the Cosmos (1997), his book on CNS and other subjects for lay readers, by the mid-1990’s his team had been able to sensitivity test, via mathematical simulations, eight of approximately twenty apparently fundamental parameters. In such tests to date, Smolin claims our present universe appears to be fine-tuned both for long-lived universes capable of generating complex life and for the production of hundreds of trillions of black holes, or for ‘fecundity’ of black hole production.
His theory has been critiqued on occasion (Vaas 1998; Vilenkin 2006), and continues to be elaborated and defended (Smolin 2001,2006). McCabe (2006) states that research in loop quantum gravity “appears to support Smolin’s hypothesis” of a bounce at the center of black holes forming new universes (see also Ashtekar 2006). If true, such a mechanism would suggest an organic type of reproduction with inheritance for universes, and the universe ensemble might be characterized as an extended, branching chain exploring a ‘phenospace’ of potential forms and functions within the multiverse.
Antecedents to CNS
In an update of the oscillating universe model of Alexander Friedman (1922), and the Phoenix universe model of Georges Lemaître (1933) physicist John A. Wheeler (1973,1977) proposed that the basic laws and constants of the universe might fluctuate randomly to new values at each successive bounce (new universe birth), and thus provide a natural mechanism for anthropic selection.
Though these original simpler oscillation models did not survive criticism, some theorists continue this work in both the cyclic model in brane cosmology, and in the theory of cosmological natural selection. The cyclic model remains controversial as it presently offers no satisfactory description of the bounce via string theory. Furthermore, recent empirical evidence that universal expansion is not slowing but is accelerating (observation of distant supernovae as standard candles, and the mapping of the cosmic microwave background), would argue that a future Big Crunch is unlikely. Nevertheless, an oscillating model cannot yet be ruled out as the nature and future dynamics of the dark energy that drives universal acceleration is not yet known.
Curiously, the advent of dark energy models since 1998 suggests an even more biologically-analogous model of universe replication via CNS. For example, Nagamine and Loeb (2003) propose that under dark energy our universe must self-fractionate into a number of informational 'islands,' each of which undergoes gravitational collapse. Our local island comprises the Milky Way and Andromeda galaxies, and the latter will apparently start to collide in just 20 billion years. In this model then, rather than an oscillating universe which returns all its evolutionary species to a single replication point in a "Big Crunch," we are left with series of branching replications, as in any evolutionary developmental lineage of living systems exploring a phenospace. Such a branching replicative pattern is also seen in many nonliving replicating systems, such as stars replicating in an evolving and developing galaxy.
Beginning in the 1980’s theorists in quantum gravity began postulating that our universe might ‘give birth’ to new universes via fluctuations in spacetime over very short distances (Baum 1983; Strominger 1984; Hawking 1987,1988,1993; Coleman 1988). Some theorists (Hawking 1987; Frolov 1989) proposed that new universe creation might be particularly likely in the singularity region inside black holes.
As Victor J. Stenger observes (1999), prior to Smolin's 1992 article Quentin Smith (1990) independently proposed that random symmetry breaking events in the initial Big Bang singularity, and in black hole singularities that form in universes of our type, might lead to the production of new universes via black holes, and this could provide a naturalistic explanation for the emergence of the basic laws and constants of our universe.
CNS with Intelligence (CNS-I)
Crane's Meduso-anthropic principle first proposed (in an arxiv.org preprint in 1994) including a role for intelligence in the CNS replication process, a theoretical approach we may call "CNS-I". Cosmologist Edward Harrison (1995) independently proposed that the purpose of intelligent life is to produce successor universes, in a process driven by natural selection at the universal scale. Harrison's work was apparently the first CNS-I hypothesis to be published in a peer-reviewed journal.
James N. Gardner (2000,2003,2007) has explored CNS-I ideas at length in his selfish biocosm hypothesis. After Dawkins (1976) approach to evolutionary biology, Gardner envisions self-preserving and self-selecting universal replication mechanics, which eventually lead to advanced ancestor intelligences as architects of our curiously fine-tuned universe.
Smart (2000,2008) approaches CNS-I via an evolutionary and developmental (evo devo) universe hypothesis. After Lloyd (2000), he proposes a constrained developmental destiny for higher universal intelligence in the form of black hole computational entities, in his developmental singularity hypothesis. In contrast to Gardner's universal 'architects', Smart envisions only a very limited capacity for end-of-universe evolutionary intelligence to alter universal developmental ('seed') parameters in each replication cycle, in the same way that evolutionary process alters developmental genetics only imperceptibly in each replication in biological systems. Our multiversal environment, by contrast, might be modified by ancestor intelligences to a significantly greater extent, via niche construction, again as seen in higher biological systems (Odling-Smee 2003).
Vidal (2008, 2009), also takes an evolutionary and developmental approach to CNS-I. He proposes that an intervention of intelligence in the universal reproduction process should be named "Cosmological Artificial Selection". In this scenario, a cosmic blueprint would be artificially fine-tuned by intelligence. The selection process would then not be random or natural, but mediated by intelligence, or artificial.
- Baum, Eric (1983) Discussion, Physics Letters B 133(185).
- Coleman, Sidney (1988) Black holes as red herrings: topological fluctuations and the loss of quantum coherence. Nuclear Physics B 307(864).
- Crane, L. 1994 (2009) Possible Implications of the Quantum Theory of Gravity: An Introduction to the Meduso-Anthropic Principle. Foundations of Science Preprint 1994, no. Special Issue of the Conference on the Evolution and Development of the Universe (EDU-2008). In press. http://evodevouniverse.com/EDU2008Papers/CranePossibleImplicationsQuantumGravityEDU2008.pdf.
- Dawkins, Richard (1976/2006) The Selfish Gene, Oxford University Press.
- Friedman, Alexander (1922) Über die Krümmung des Raumes. Zeitschrift für Physik 10(1):377–386. doi:10.1007/BF01332580. (English trans. in: Gen. Rel. Grav. 31(1999)1991-2000.
- Frolov, Valeri P. et. al. (1989) Through a black hole into a new universe? Physics Letters B 216:272-276.
- Hawking, Stephen W. (1987) Coherence down the wormhole. Physics Letters B 195(337).
- Hawking, Stephen W. (1988) Wormholes in spacetime. Physical Review D 37(904).
- Hawking, Stephen W. (1993) Black Holes and Baby Universes – and Other Essays (Amazon), Bantam. ISBN 0553374117
- Lemaître, Georges (1933) Discussion sur l'évolution de l'univers, Annales Soc. Sci. Brux. Ser. I A 53, 51.
- Lloyd, Seth (2000) Ultimate physical limits to computation. Nature 406:1047-1054.
- Misner, Charles, Thorne, Kip and Wheeler, John A. (1973) Gravitation, Freeman, §44.6, pp. 1196-1217. (This section based on a lecture by Wheeler) ISBN 716703440
- Nagamine, Kentaro and Loeb, Abraham (2003) Future Evolution of Nearby Large-Scale Structures in a Universe Dominated by a Cosmological Constant. New Astronomy 8:439-448. http://arxiv.org/PS_cache/astro-ph/pdf/0204/0204249v3.pdf
- Odling-Smee, F. John et. al. (2003) Niche Construction: The Neglected Process in Evolution, Princeton U Press.
- Smart, John (2000) Intro to the Developmental Singularity Hypothesis, Retrieved from AccelerationWatch.com
- Smart, John (2008) Evo Devo Universe? A Framework for Speculations on Cosmic Culture. In Cosmos and Culture, ed. S. J. Dick and Mark Lupisella, NASA Press.
- Smith, Quentin (1990) A Natural Explanation of the Existence and Laws of Our Universe (html). Australasian Journal of Philosophy 68:22-43.
- Smolin, Lee (1992) Did the Universe Evolve? Classical and Quantum Gravity 9:173-191.
- Smolin, Lee (1994) The fate of black hole singularities and the parameters of the standard models of particle physics and cosmology (PDF). arXiv:gr-qc/9404011v1
- Smolin, Lee (1997) The Life of the Cosmos (Amazon), Oxford U. Press. ISBN 0195126645
- Smolin, Lee (2001) Three Roads to Quantum Gravity (Amazon), Basic Books. ISBN 0465078362
- Smolin, Lee (2006) The status of cosmological natural selection (PDF). arXiv:hep-th/0612185v1
- Stenger, Victor J. (1999) The Anthropic Coincidences: A Natural Explanation (html). The Skeptical Intelligencer Vol. 3(3).
- Strominger, Andrew (1984) Vacuum topology and incoherence in quantum gravity. Physical Review Letters 52(1733).
- Vaas, Rüdiger (1998) Is there a Darwinian Evolution of the Cosmos? Some Comments on Lee Smolin’s Theory of the Origin of Universes by Means of Natural Selection (html). Proceedings of MicroCosmos – MacroCosmos conference, Aachen, Germany, 2-5 Sep 1998. http://arxiv.org/abs/gr-qc/0205119.
- Vidal, Clement (2008) The Future of Scientific Simulations: from Artificial Life to Artificial Cosmogenesis. In Death And Anti-Death, ed. Charles Tandy, 6: Thirty Years After Kurt Gödel (1906-1978).:285-318. Vol. 6. Ria University Press.
- Vidal, Clement (2009) Computational and Biological Analogies for Understanding Fine-Tuned Parameters in Physics. Foundations of Science, no. Special Issue of the Conference on the Evolution and Development of the Universe (EDU-2008). In press.
- Vilenkin, Alexander (2006) On cosmic natural selection (PDF). http://arxiv.org/abs/hep-th/0610051.
- Wheeler, John A. (1977) In: Foundational problems in the special sciences, Reidel, Dordrecht, pp. 3–33.
This page is a stub. If you are a member of the EDU community you can help by expanding it.