Approaches to the finetuning problem in cosmology: a critical overview'

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• Approaches to the fine-tuning problem in
  cosmology a critical overview.
• Clément Vidal (CLEA/ECCO)
• clement.vidal_at_philosophons.com

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Outline

• Introduction
• Origin of the FT problem numerology?
• Classical approaches
• Theory of everything, God, Multiverse,
• Anthropic Principles
• Evolutionary approaches
• Smolins Cosmological Natural Selection (CNS)
• Limitations and a possible extension

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1. Introduction
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Origin of the fine-tuning problem

• Shift of the traditional problem of design in the
  Fine-Tuning (FT) problem in cosmology.
• Three options in the history of ideas
• The universe was created by an intelligent
  entity.
• The universe was not created by an intelligent
  entity.
• This is a meaningless question.

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The Fine-Tuning (FT) Problem

• If any of the fundamental constants were slightly
  different, our universe wouldnt develop matter,
  structures like galaxies, solar systems or life.
  (e.g. Leslie 1989, Rees 2000, etc.).
• Two sets of fine-tuned parameters
• Free parameters in standard cosmological models
  of the Big Bang
• Free parameters in the standard model of particle
  physics.

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Numerology?

• Analogy with mathematical constants (PI, Chaisson
  2006, preface).
• Constants not constant.
• The coupling constants (dimensionless) are
  defined at a certain level of energy, and change
  at different energy levels. (Demaret, Lambert
  1994, 4)
• Competing model to inflation, with a variation of
  the speed of light (Magueijo 2003)
• Changing one parameter (classical FT arguments).

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Changing more parameters

• Constants are linked in physics
• e.g. speed of light (c) and (mu0)
• Changing a constant also means perturbing orther
  constants.
• Contemporary and future of cosmology science
  explore the possible combinations systematically
  with simulation.
• (e.g. Victor Stengers (2001) MonkeyGod)

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2. Classical approaches to the FT problem
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Meaningless problem? (1)

• FT argument assumes
• things could have been different (implies
  counterfactual reasoning)
• we can assign probabilities to the set of
  unrealized possibilities in an invariant way.
  (Ellis 2005, 20)
• Chance, brute fact.

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Meaningless problem? (2) FT and probabilities

• "Thesis A4 The concept of probability is
  problematic in the context of existence of only
  one object. Problems arise in applying the idea
  of probability to cosmology as a whole it is
  not clear that this makes much sense in the
  context of the existence of a single object which
  cannot be compared with any other existing
  object." (Ellis 2005, 20)

• How to define the probablility ensemble?
• Fine or coarse tuning?

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Physical necessity (TOE)

• Chew (1968) "nature is as it is because this is
  the only possible nature consistent with itself".
  
•  Theory of everything  (TOE) in physics. Dream
  of a theory that would decide the values of all
  the constants in a determined manner.
  Position/speculation of most physicists.
• Very difficult. Even if it would succeed, what
  would it mean?...

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God

• Design hypothesis our universe is the result of
  a purposeful design. Not necessarily a theistic
  God.
• Design by God shifts the problem to theological
  questions nature of God, etc...
• Many very different interpretations of  God
  e.g. in process philosophy/theology.
• (Kant 1781, B655) We can argue for an ARCHITECT
  of the universe, but not deduce the existence of
  a God with all its nice characteristics we want
  him to have.

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God as the great architect

• Free masonery. God doesn't intervene. He just
  gives a blueprint.
• Allows the development of science
  (sciencefinding God's laws)
• Very different from a controlling God.

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The Anthropic Principle (AP) as a source of
confusion

• "Anthropic principles serve only to obfuscate."
  (Swinburne 1990, 172, in Ellis 1990).
• 30 different formulations (Bostrom 2002, 6).
• Some scientists sometime say its no science at
  all (Pagels, Gratton, Rees, etc.), others says
  its very important for science (Ellis, Rosen,
  Hawking, etc.).
• What are the sins of the AP? Why is it dangerous,
  perverse, etc... for science?

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The two main difficult problems behind the
Anthropic Principle(s)

• (1) Observational selection effect (OSE)
• Carters original paper (1974), (WAP and SAP)
• (Bostrom 2002). In depth study of OSE.
• (2) Teleology finality
• Age old philosophical question.

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Carters original APs state only observational
selection effects.

• Weak Anthropic Principle (WAP) The existence of
  observers in the universe impose temporal
  constraints on the positions of the observers in
  the universe.
• Strong Anthropic Principle (SAP) The existence
  of observers in the universe impose constraints
  on the set of cosmological properties and
  constants of the universe.

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Observational selection effectMalmquist bias
example.

• Let X be a population of luminous objects, with
  different luminosities.
• At a distance from X, we will only see the most
  luminous objects.
• Thus, the average luminosity will appear to
  increase with distance
• (Ellis 2005, 10)

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Teleology

• Definition the fact or character attributed to
  nature or natural processes of being directed
  toward an end or shaped by a purpose.
• See (Demaret, Lambert 1994, chap 9, 10)

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Anthropic Principles

• Observational selection effect
• Can lead to predictions
• General problem of science

• Teleological principle
• Cannot lead to predictions
• Age-old philosophical problem

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AP conclusion

• Davies, Barrow and Tipler have unfortunately
  redefined the SAP as equivalent to a teleological
  principle.
• Indeed teleological reasoning is difficult to
  make scientific.
• When the expression Anthropic Principle is
  used, you should ask "is the debate about
  selection effects or teleology?"
• A serious discussion of the anthropic principle
  doesn't mention the anthropic principle!

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Summary

• Chance
• Necessity (TOE)
• Universality (All possibilities, i.e.
  WAPMultiverse).
• God (form purpose or design)

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3. Evolutionary approaches to the FT problem
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Smolin's Cosmological Natural Selection (CNS)

• Arguably the best variant of the multiverse
  hypotheses. See (Smolin 1997) for an overview of
  CNS.
• Parcimonious (compared to other multiverse
  hypotheses).
• Suggests observational tests.

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Lee Smolins Cosmological Natural Selection (CNS)

• The situation of nowadays physics is analogous to
  the biologists before Lamarck and Darwin.

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Smolins theory

• NOT brute multiverse
• Black holes give birth to new universes
  (space-time regions.)
• This event is like a big bang, and can give rise
  to new physical constants.
• The properties of the elementary particules are
  slightly different from the mother universe.

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Limitations of Smolins theory

• Lifes role in the universe is incidental.
• The physical laws arent fine-tuned to maximize
  black hole production. (Rees 1997, p251), quoted
  in (Gardner 2003, p84)
• No mechanism of heredity. (Gardner 2003, p84)

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Scope of cosmology

• (1) Why do the laws of physics have the form they
  do? (FT)
• (2) Why do boundary conditions have the form they
  do? (FT)
• (3) Why do any law of physics at all exist?
  (ontology)
• (4) Why does anything exist? (ontology/metaphysics
  )
• (5) Why does the universe allow the existence of
  intelligent life? (link intelligence-universe)
• (Ellis 2005, section 8.2)

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Approaches to cosmology

• Decide to exclude the previous questions
  strictly scientific cosmology. BUT then you do
  not tackle very important questions.
• Decide to tackle the questions, even if we get
  outside observational and experimental support.
• God, Multiverse, thats what they all do.

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Speculative philosophy

• Tackling problems without the help of
  observational and experimental support is very
  different from a traditional scientific enquiry.
• How to best answer problems where we cant have
  any direct observational/expermimental support?
• This becomes a problem of speculative philosophy.
  Detailed answer (Vidal 2007b) Worldview
  construction.

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CNS Intelligence

• Extension Smolins theory, including intelligent
  life in the theory, and thus tackling the very
  important question (5).
• How is it called?
• Meduso Anthropic Principle (Crane 1994)
• The natural selection of universes containing
  intelligent life (Harrisson 1995)
• Cosmological replication cycle (Balaz 2001)
• Biocosm Intelligent life is the architect of the
  universe (Gardner 2003)
• Developmental Singularity Hypothesis (John Smart,
  http//www.accelerationwatch.com/ )
• Other suggestion Cosmological Artificial
  Selection (CAS).
• Martin Rees, Paul Davies, Ray Kurzweil (2006)
  like the idea. (note this point is only an
  authority argument, it doesnt mean much!).
• more details in months/years to come

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Conclusion (1)

• God
• FT Ok.
• Ultimate origin Ok.
• Question (5) (in slide  scope for cosmology )
  No
• Multiverse
• FT Ok.
• Ultimate origin No.
• Question (5) No.

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Conclusion (2)

• CNS
• FT Ok.
• Ultimate origin No
• Question (5) No.
• CNSIntelligence
• FT Ok.
• Ultimate origin Yes (with infinite cycles)
• Question (5) Yes

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Thank you for your attention !

• Questions are welcome now or later
• clement.vidal_at_philosophons.com

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References (1)

• Balázs, B.A. (2001),  The Cosmological
  Replication Cycle , the Extraterrestrial Paradigm
  and the Final Anthropic Principle, in Proceedings
  of the 12th Congress of the International
  Association Cosmos and Philosophy
• Bostrom, N. (2002) Anthropic Bias Observation
  selection effects in Science and Philosophy.
  Routlege, NY.
• Carter, B., (1974) Large Number Coincidences and
  the Anthropic Principle in Cosmology, in
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  M.S. Longair, Editor. Reidel Dordrecht. p.291-
  298.
• Chaisson, E. (2006) The Epic of Evolution.
  Columbia University Press.
• Chew, G.F., (1968) "Bootstrap A Scientific
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• Crane, L. (1994) Possible implications of the
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• Demaret, J., Lambert, D. (1994) Le Principe
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• Gardner, J. N., (2003) Biocosm. The new
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  Publishing.

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References (2)

• Harrison, E. (1995) The natural selection of
  universes containing intelligent life. Quart. J.
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  http//adsabs.harvard.edu/full/1996QJRAS..37..369B
  
• Kant, E. (1781), Critique of the pure reason.
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• Rees, M., (1997) Before the beginning Our
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• Stenger, V. (2001) MonkeyGod (document explaning
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  vstenger/Cosmo/MonkeyGod.pdf
• Swinburne, R. (1990) Argument from the
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• Vidal. C. (2007b) An Enduring Philosophical
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