Does God So Love the Multiverse

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Does God So Love the Multiverse?

• Don Page
• Department of Physics
• University of Alberta
• Edmonton, Alberta, Canada

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God So Loved the World

• A central point of Judaism and Christianity is
  that God loves everyone.
• John 316 For God so loved the world that He
  gave His only begotten Son, that whoever believes
  in Him should not perish but have everlasting
  life.

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Gods Old Testament Love

• God began a revelation through the family of
  Abraham, Isaac, and Jacob.
• Gods love was extended to Ruth, a foreigner who
  became ancestor to Israels greatest king, David.
• Jonah was called to preach repentance and
  forgiveness to the hated Ninevites.

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Gods New Testament Love

• Jesus came to bring forgiveness and salvation to
  those who broke the laws God gave to the
  Israelites.
• He told His disciples to make disciples of all
  nations.
• Peter and Paul began the work of extending the
  Gospel message beyond the Israelites to all
  nations.

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Created in Gods Image

• Genesis 127 God created man in His own image
  in the image of God He created them male and
  female He created them.
• How unique does that make us?
• The Bible certainly emphasizes that the image of
  God extends to all humans.

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Are We Created Separately?

• Some took the image of God for humans to imply
  that God created us individually and separately
  from other living things.
• Darwins theory of evolution suggests that we are
  related to the rest of life.
• It also suggests that we humans were not
  separately created by an individual act.
• However, it does not disprove creation.

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Christian Response to Evolution

• When Darwin proposed evolution, many conservative
  Christians accepted it.
• However, many later came to oppose it.
• It did remove one particular design argument for
  the existence of God.
• Nevertheless, it did not disprove the existence
  of God or of design.

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Fundamentalist on Evolution

• Benjamin B. Warfield (1851-1921), the
  conservative Christian theologian and principal
  of Princeton Seminary from 1887 to 1921, who
  wrote the chapter on The Deity of Christ in The
  Fundamentals (1917)
• I am free to say, for myself, that I do
  not think that there is any general statement in
  the Bible or any part of the account of creation,
  either as given in Genesis 1 and 2 or elsewhere
  alluded to, that need be opposed to evolution.

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Fine-Tuning as Evidence for Design?

• Before Darwin, some Christians took the marvels
  of humanity as evidence of separate and
  individual design.
• Now, some Christians take the marvels of the
  constants of physics as evidence of separate and
  individual design.
• It could be that this is equally mistaken.

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Fine-Tuned Constants

• It does seem true that we could not be here if
  many of the constants of physics were
  significantly different.
• If the mass and charge of the proton and electron
  were much different, suitable stars to produce
  elements and to sustain planets could not exist.
• If the cosmological constant werent so tiny,
  structures would not form at all.

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Explanations of Fine Tuning

• Some say the fine tuning was done separately by
  God to allow life.
• Others say that it is an accidental fluke.
• Yet others say it arises from a huge multiverse
  of very many different possible constants of
  physics.

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Steven Weinberg

• Living in the Multiverse, in Bernard Carr,
  ed., Universe or Multiverse? (CUP, 2007)
• Just as Darwin and Wallace explained how the
  wonderful adaptations of living forms could arise
  without supernatural intervention, so the string
  landscape may explain how the constants of nature
  that we observe can take values suitable for life
  without being fine-tuned by a benevolent creator.
  I found this parallel well understood in a
  surprising place.

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Christoph Cardinal Schoenborn New York Times, 7
July 2005

• Now, at the beginning of the 21st
  century, faced with scientific claims like
  neo-Darwinism and the multiverse hypothesis in
  cosmology invented to avoid the overwhelming
  evidence for purpose and design found in modern
  science, the Catholic Church will again defend
  human nature by proclaiming that the immanent
  design evident in nature is real.

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Weinbergs Response

• It's nice to see work in cosmology get
  some of the attention given these days to
  evolution, but of course it is not religious
  preconceptions like these that can decide any
  issues in science.
• Here I (DNP) wish to go on record as a
  Christian who respectfully differs from Cardinal
  Schoenborn's opinion.

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Reasons Some Multiverse Hypotheses Were Invented

• Everett many-worlds To circumvent the
  measurement problem of quantum mechanics
• Inflation To solve the flatness, homogeneity,
  isotropy, and magnetic monopole problems of
  cosmology
• String landscape To match properties of string
  theory solutions

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Artificial and Natural Multiverses

• Some multiverse theories seem too artificial or
  contrived to be plausible, such as David Lewis
  modal realism idea that everything logically
  possible exists, or Max Tegmarks idea that all
  mathematical structures actually exist.
• Other multiverse theories might arise naturally
  out of elegant laws of nature.

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Multiverses from Physics

• One natural way to get a multiverse is to have a
  universe so large that highly varied conditions
  occur somewhere.
• Another way is from Everett many-worlds, that all
  the quantum possibilities actually are realized.
• However, these possibilities do not necessarily
  give varying constants of physics.

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Multiverses from Inflation

• Inflation is a very rapid expansion of the early
  universe that may make the universe very much
  larger than what we can observe of it.
• If constants of physics can differ across phase
  transitions, inflation tends to produce all such
  possibilities.

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Multiverses from Strings

• Recently it has been realized that string/M
  theory apparently leads to a huge multiverse of
  10500 or so different vacua or sets of constants.
• This would apparently be enough for the constants
  we see to occur somewhere (maybe one per 10200
  vacua or so).
• Then 10300 vacua would fit what we see.

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Multiverse Explanation

• If only one universe in 10M could fit our
  observations, but if 10N universes exist in the
  multiverse, then it might not be surprising that
  what we observe exists if N M.
• We dont yet know whether N M in string/M
  theory, but it is plausible.
• Then what we see could be explained without its
  having to be individually selected.

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Does the Multiverse Explanation Always Work?

• Is it sufficient to explain what we see by a
  multiverse theory in which there are enough
  different conditions that ours necessarily occurs
  somewhere?
• I would say no, that the conditions we observe
  should not be too rare out of all the conditions
  that are observed.
• A theory making our observations too rare should
  not be considered a good theory.

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Bayesian Reasoning

• Good theories should both be intrinsically
  plausible and fit observations.
• Intrinsic plausibility is quantified by the a
  priori probability of the theory.
• Fit to observations is quantified by the
  probability of the observation given the theory
  (the likelihood).
• Bayes formula gives the probability of a theory
  as being proportional to the product of the a
  priori probability and the likelihood.

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A Priori Probabilities

• A priori probabilities of theories (intrinsic
  plausibilities before considering observations)
  are subjective but generally are assigned higher
  values for simpler theories (Ockhams razor or
  law of parsimony of postulates).
• David Deutsch notes that simplicity depends on
  ones background knowledge that depends on the
  laws of physics themselves.

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Likelihoods

• The likelihood is the conditional probability of
  the observation, given a particular theory.
• A theory that uniquely gives ones observation
  would have unit likelihood but might have very
  low a priori probability (e.g., solipsism with
  only the present moment).
• The other extreme, a simple theory that predicts
  all possible observations equally, would have
  high a priori probability but low likelihood for
  our particular observation.

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Sample Bayesian Calculation

• Let T1 have a priori probability 0.0000001 and
  give probability 1 for what we see.
• Let T2 have a priori probability 0.001 and give
  probability 0.01 for what we see.
• Let T3 have a priori probability 0.999 and give
  probability 0.0000001 for what we see. Assume
  this exhausts all theories.
• Then T1 has a posteriori probability 0.01, T2 has
  probability 0.98, and T3 has 0.01.

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Guessing Gods Motives

• Suppose we guess that God wants to create the
  simplest universe with beings like us.
• If the constants of physics we see are optimal,
  it might be simplest for God to choose them and
  them only.
• They do seem very good, but it is not clear that
  they are optimal, so it might be simpler for God
  to choose a set of varying constants, a
  multiverse rather than a single universe.

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Progressing to Multiverses

• Ones present observation - solipsism - ones
  family - ones nation - ones race - all
  humans on earth - conscious animals -
  extraterrestrials - observers not in causal
  contact with us - observers in disconnected
  universes - observers in other branches of a
  many-world wavefunction - observers in universes
  with different constants of physics -
  observers in entirely different universes.

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Scientific Objections to Multiverses

• Not observable or testable. But if one had a
  theory giving the distribution of different
  conditions, one could make statistical tests of
  our observations (likely or unlikely in the
  distribution). Unfortunately, no such theory
  exists yet.
• Not a clear consequence of any theory. But need
  to calculate consequences.

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Psychological Objections to Multiverses

• It would make things more complicated. But the
  whole can be simpler than the parts, as the whole
  set of integers is simpler than most individual
  integers.
• One seems insignificant if not unique. But ones
  purpose and significance need not depend upon
  being unique.

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Philosophical Objections to Multiverses

• Extravagant to assume unfathomable numbers of
  unobservable universes. But they may be easy for
  God to create. He may prefer elegance over
  paucity.
• Can be used to explain away anything. But one
  needs that they make our observations not too
  improbable out of all possible observations.

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Theological Objections to Multiverses

• No more fine-tuning argument for God. But the
  loss of one argument does not mean that its
  conclusion is necessarily false.
• God has nothing to left to design. But God could
  have designed the entire multiverse.
• If other civilizations have Christ, His death is
  not unique as the Bible says. But His death
  might be unique for our human civilization.

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Conclusions

• Multiverses are serious ideas of present science,
  though not yet proved.
• They can potentially explain fine-tuned constants
  of physics but are not an automatic panacea for
  solving all problems.
• Though multiverses should not be accepted
  uncritically, I would argue that Christians have
  no more reason to oppose them than they had to
  oppose Darwinian evolution when it was first
  proposed.
• God might indeed so love the multiverse.