Questions and Views 
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Intelligent Design of the Universe & Nature?

Fine Tuning and the Anthropic Principle,

Intelligent Design and/or Multiverse

Was the universe intelligently designed by God?
A fine tuning of nature is strongly indicated by science,
so our main question is "Why does the fine tuning exist?"
 This page describes answers being proposed by Christians and others.

The sections in this page are:
plus a Summary of Basic Principles and explorations of Science & Philosophy & Theology
 { italicized links move you to another part of this page, non-italicized links open a new page in this window } 

    STRONG EVIDENCE indicates that our universe is “just right” for life.  PLAUSIBLE EXPLANATIONS for this fine tuning of nature include a designed universe, a designed multiverse (that contains many universes with differing properties of nature), and a non-designed multiverse.
    Scientific theories proposing a multiverse are educated speculation;  other universes could not be observed even if they existed, and there are logical reasons to accept or reject various multiverse theories.  A confident conclusion seems impossible when we ask, “does a multiverse exist?” and “if it exists, what are its characteristics?”, so humility is justifiable.
    Although a multiverse would weaken some arguments for intelligent design, this is mainly a problem for apologetics.  When we think about theology by asking “is a multiverse theologically acceptable” and we focus on what the Bible teaches, some Christians say “no, this isn't how God would do it” but others think “either way is fine, with a universe or multiverse” because a multiverse would have no practical effects on what happens in our universe.  Even though unanswered questions about a multiverse may affect some of the ways we think about some ideas, the practical effects on everyday living will be minimal for Christians if we don't let the controversies decrease our ability to trust God and live by faith.  And there are good reasons to conclude that the unanswered questions should not lead to a decrease in faith.

Speculations about a multiverse are becoming more common in media and education.  The main goals of this page are to clearly explain these fascinating ideas so you can understand them, and to put the ideas in perspective by explaining why we should humbly acknowledge that “we just don't know whether or not a multiverse exists,” and why a multiverse (if it does exist) would not affect us in any tangible way, and why speculative ideas about a multiverse should have minimal practical effects on the everyday ways we think and live, on our decisions, actions, and relationships.


    In recent decades, scientists have discovered that our universe is “just right” for life.  To understand this fine tuning, imagine a control panel with dozens of dials.  To allow life, each dial — which controls one property of nature — must be properly tuned within a narrow range.  You are alive because nature's dials are properly fine tuned, and this allows a wide variety of life-permitting natural phenomena, including our sun and other stars (which produce the energy and atoms needed for life), and the biochemistry of DNA, water, and proteins.
    Most scientists agree that many life-allowing features of nature, ranging from the physics of sunshine to the chemistry of life, require a fine tuning of nature:

    Cosmic Design in a Nutshell is a quick summary by the IDEA Center.  {amount of text in main body of their page is 2 k}
    But a brief TalkOrigins FAQ disputes the claims that nature is fine tuned for life, and argues against a conclusion of Intelligent Design.  {3 k}
    Evidence for Fine Tuning by Rich Deem, includes a list of Fine Tuning Parameters from Hugh Ross.  {10 k}
    Francis Collins (writing for Biologos Foundation, with advice from Owen Gingerich) describes Fine Tuning of the Universe and also examines possible explanations, so this is a transition from evidence (left side) to explanations (right side).  {14 k}



    As explained in STRONG EVIDENCE for Fine Tuning, "Scientists agree that..."  But we disagree about which theory is the best explanation.  Do we live in:  1a) an intelligently designed universe, or   1b) a non-designed universe [this seems unlikely], or   2a) an intelligently designed multiverse that contains an immense number of universes (including the one we observe and many more) with variable properties, so extremely improbable things, such as properties allowing life, will occur in at least one of these universes, or   2b) a non-designed multiverse?
    On the left side, an intelligently designed universe is proposed by IDEA Center, Rich Deem, and Biologos Foundation.  But some scholars think a fine tuning of nature could be explained by a non-design theory.

    Deborah Haarsma & Loren Haarsma ask, Does the Scientific Evidence of Fine Tuning prove the Existence of God?  {size of page = 5 k}
    Fine Tuned Universe and Possible Explanations from Word-IQ.  {5 k}
    3 of the 4 basic theories about fine tuning in our "just right" universe seem plausible, says Craig Rusbult (editor of this links-page), who also looks at theological implications.  {16 k for Section 5B in his FAQ}
    The ideas of Leonard Susskind — who proposes a diverse multiverse in The Cosmic Landscape: String Theory and the Illusion of Intelligent Design — are described in a book review by Corey Powell.  {7 k}
    Why intelligent life?  7 possibilities, described by Paul Davies in Cosmic Jackpot, are summarized by David Bailey.  {10 k}


BASIC PRINCIPLES (an overview-summary)
A web-page cannot explain everything, so each writer must skip some important ideas.  This leaves gaps in your knowledge, which can make it difficult to see the big picture (the whole network of related ideas) because some parts of the puzzle are missing.  The goal of this section is to help you quickly build a solid foundation of understanding that will make it easier for you to learn more while you're exploring the educational resources.

        Fine Tuning:  The properties of nature (its qualitative characteristics, numerical constants, and initial conditions) seem to be fine tuned for life, as explained above in the left-side introduction.
        Explanations:  Four possible explanations for the fine tuning in our universe — with design or non-design, in a universe (i.e. a single-universe that is the only universe) or a multiverse (i.e. in a multiverse-universe, a universe within a multiverse) — are in the right-side introduction.
        Anthropic Principle:  When someone says "anthropic principle" without defining it, their meaning is not clear because different people have defined four versions of the anthropic principle (weak, strong, participatory, final) in ways that differ in their relationships with fine tuning and what is claimed about it.  Basically, the simple anthropic principle merely states that because humans exist, we must observe a universe consistent with our existence.  This logical statement seems obviously true, but it does not provide support for either design or non-design;  it does not explain why our universe is fine tuned for life;  but it does describe what can be observed, and in a multiverse it would explain where fine tuning is observed, in two anthropic selection effects that make it a useful selection principle.  The simple anthropic principle is logically valid.  But other versions, claiming more than this, can be speculative and controversial, so when someone says "anthropic principle" you should try to determine their intended meaning for this ambiguous term.
        Life-Allowing versus Life-Producing:  We are here, so the properties of nature must allow intelligent life.*  If this simple anthropic principle is supplemented by assuming a totally natural history of life, the inescapable conclusion will be that the properties of nature also must produce intelligent life by 100%-natural evolution.  Either possibility, a universe that is only life-allowing or is also life-producing, should be theologically acceptable to theists who think God can do miracles;  but a claim that the formative history of nature was all-natural (as proposed by theistic evolutionary creationists and others, including atheists and dedicated agnostics) requires a universe that is naturally life-producing.    {* This claim ignores the possibility of life being sustained by continual miracles, which doesn't seem necessary in our universe. }

        Multiverse Speculations:  Because a multiverse is speculative, with no direct observational evidence, our thinking about a multiverse should begin with conditional if-then logic, by thinking "IF a physical multiverse exists in reality (not just in imaginative theories), then..."
        Appropriate Humility:  When we're thinking about intelligent design and/or a multiverse, appropriate humility — not too little, and not too much — is justifiable for both physics and metaphysics.  The result of failing to recognize (or acknowledge) a rational level of appropriate confidence is described by Bertrand Russell: "Error is not only the absolute error of believing what is false, but also the quantitative error of believing more or less strongly than is warranted by the degree of credibility properly attaching to the proposition believed, in relation to the believer’s knowledge."

      definition of universe:  Traditionally, universe has meant "everything physical that exists" so there is only one universe.  But in current cosmology, universe is used in several ways;  the usual meaning is everything resulting from a particular ‘big bang’ expansion.  We can also define our own observable universe;  it ends at a visual horizon because we could not see the light traveling from any further distance.

        Universe-Types and Actualized-Universes:  This distinction, between types & actualizations, is important.*  IF a multiverse exists, it might contain many types of universes, with each type having different properties of nature;  and each of these universe-types might occur in many actualized-universes that have the same properties of nature, but different histories due to differing initial conditions plus the divergences described in chaos theory.  If there are enough actualized-universes of a particular universe-type, the histories might begin to “repeat” so some people are concerned about potential duplicates of yourself.   /   Basically, the number of universe-types is important for questions about a divine design of nature, and the number of universe-actualizations is claimed to be a problem (but there are reasons to disagree) for Christian theology.

        Anthropic Reasoning   ( beating the odds with a diverse multiverse + anthropic selection )
        A Multiverse and Intelligent Design:  A multiverse could "beat the odds" in 2 ways (with many universe-types or many actualized-universes, or both) and thus weaken the logical support for 2 of the 4 types of claims for intelligent design:
        #1. Design of Nature:  If a multiverse exists, and if it contains enough universe-types, the fine-tuned properties of nature that seem highly improbable in a single-universe (so design is required?) will become more probable in a multiverse-universe, and all that's needed is for one (or more) of the many universe-types to be fine tuned for life, plus observer-selection by the Anthropic Principle.   /   It's analogous to getting XJQKA of the same suit, which is a royal flush:  in one 5-card deal it's highly improbable;  but in 10 million deals there is a high probability of seeing many royal flushes, due to the increase of probabilistic resources.  Here is the analogy: In an immense number of hands {universes} almost all will not be a royal flush {will not be fine-tuned for life} but, based on probabilities, we expect that at least one will be.  If there is a multiverse that has diversity because it contains a wide range of universe-types, due to the constraints of fine tuning almost all of these universe-types would be lifeless, but because of anthropic selection any observations of fine tuning would be limited to universes that are fine tuned for life.  This claim for "beating the odds with a diverse multiverse" is anthropic reasoning and its anti-design goal is explaining how the fine tuning can be only an appearance of design rather than actual design.   /   Was nature intelligently designed?  We can evaluate the arguments (scientific plus philosophical & theological) in three stages, by estimating the strength of evidence for:  a) fine tuning of nature-properties,  b) anthropic reasoning with a multiverse,  c) design of a multiverse.   Regarding c, we should ask would a universe-producing mechanism have to be designed? and we should think of the three options in "multiverse and/or design" instead of the either-or restriction of "multiverse or design."
        #2. Design-Directed Action during the history of nature:  If we think there are many actualized-universes of our type, then while evaluating the probability for a life-producing history of nature we can consider an extra factor.  In addition to the usual evaluation factors — our estimates for the probabilities of getting a planet with life-atoms (H, C, N, O, S, P, Na, K,...) and a suitable life-environment by astronomical evolution, and then a natural origin of life by chemical evolution and its subsequent development by neo-Darwinian biological evolution, plus other factors that include the possible restricting of science by methodological naturalism) we could also consider the increase in probabilistic resources that would occur in a multiverse, based on our estimate for the number of actualized-universes of our universe-type.
        For #1, a design of nature, finding a non-design explanation — which requires many universe-types (possibly spanning a string landscape?) — is a common motivation for proposing a multiverse.  For #2, design-action during the history of nature, most scientists assume that all evolutions are inevitable and will happen, even in a single-universe;  although current theories for an origin of life by chemical evolution are generally considered inadequate, the usual assumption is that future science will construct adequate theories for this evolution, or it did happen anyway despite the inadequacy of our science, but "just in case" a multiverse provides the fallback option of claiming many actualized-universes and thus many chances for a natural origin of life.
        #3 and #4. Two other possible types of intelligent design — with design-directed action by a natural agent, or natural-appearing guiding of natural process by a supernatural agent — are discussed later in Multiverse and/or Intelligent Design.

Later in this page you'll find brief descriptions of many concepts, and longer summaries for some principles:
String Theory Landscape?    Four Levels of a Multiverse?    Divine Design of a Multiverse?    Is it scientific?    Theology ( Questions about Duplicates    Proof and Faith    Humility about Creation Theology )    -=

Educational Resources
In the rest of this page you'll find idea-summaries plus links to web-resources that will help you learn more about fine tuning and possible explanations for it proposing intelligent design and (usually by claiming that our universe is part of a multiverse) non-design.  The pages below let you see what is being said by theists (mainly Christians), non-theists, and by those whose religious views are not clear.  Although there are separate sections for science, philosophy, and theology, these perspectives are "mixed together" in many pages when the authors examine ideas from more than one perspective.

You can explore the sections and subsections in any order, beginning with whatever looks interesting.

Table of Contents:
Fine Tuning - Evidence and Explanations — quick overviews
The Science of a Multiverse
— big bang & inflation, generating a multiverse, string theory, quantum splitting
Philosophy of a Multiverse
— anthropic principle, is it (multiverse or design) really scientific? ultimate origins
    questions (in philosophy & theology) about possible duplicates and semi-duplicate histories in a multiverse
Theology of a Multiverse — responses by Christians, apologetics, ethics and value, coping with strangeness

    I.O.U. — In the rest of this page, sometime (but probably not until 2016) I'll return to the process of smoothing the rough edges, and then (by selecting candidates from a temporary "holding page") more resources will be added.
    Until the process of "smoothing the rough edges" is finished, I'll write notes to myself (which are IOUs for you) that usually are marked with "-=" or by putting the comments inside [square brackets] or -=[both].

Fine Tuning — Evidence and Explanations
This section is an extension of the introduction which summarizes the evidence for fine tuning, and proposed explanations:  Are the properties of nature in our “just right” universe due to intelligent design and/or a multiverse?

Brief Overviews
These pages provide a quick "big picture overview" for many of the main ideas:
  • Do we live in a multiverse? - an interview with Paul Davies, who outlines a non-design explanation and describes reasons for asking "is it scientific?"  {3 k}
  • Our Tailor-Made Universe by Nancy Pearcey, looks at the fine-tuning evidence and proposed non-design explanations, then concludes that "if the universe appears 'tailor-made' for life, perhaps the simplest explanation is that it was tailor-made."  {5 k}
  • Multiverse and String Theory: Toward Ultimate Explanations in Cosmology introduces the scientific and philosophical ideas discussed in two symposiums, 2003 and 2005, sponsored by the John Templeton Foundation.  {3 k}
  • A longer overview by Mark Vernon explains why many scientists, and other scholars, are asking "is it scientific?" when they look at multiverse theories.  {15 k for article, excluding the comments which are generally much less worthy of reading}  {editorial comment: This difference in quality, with article much better than comments, is true for most blogs, but occasionally you'll find some valuable high-quality comments mixed in with the clutter.}
  • IOU - a few more resources, especially some with pro-design views, will be here later.
  • At the end of this page, there is more about evidence-and-explanations.

Intelligent Design of a Multiverse?
The title of this page ends with "Intelligent Design and/or Multiverse" because an effective mechanism for producing a multiverse might require fine tuning that was the result of intelligent design.  Thus, our questions about intelligent design can be shifted up one level, from a fine-tuned universe to a fine-tuned multiverse, as explained later.

The Science of a Multiverse
If you understand the science, it will help you understand philosophical and theological discussions about the possibility of a multiverse.  Here are the sub-sections for science:
Our Universe  —  The Big Bang and Inflation,  Before the Big Bang,  A Universe with Zero Total Energy
Energy, Matter, and Forces  —  Particles,  Dark Matter & Dark Energy,  String Theory & String Landscape
A Multiverse?  —  Four Category-Levels?  Possible Mechanisms (Chaotic Inflation, Black Holes, and more)

Science Websites to Explore
If you just want to read, click links, and wander, here are some websites you can explore to learn about physics and cosmology:
  • Physics of the Universe (difficult topics made understandable) has a series about The Big Bang & Big Crunch and related topics.
  • Word-IQ Encyclopedia beginning with cosmology or fine-tuned universe and check the "See Also" links for each page. sitemap  (user's tip: ignore "Example Usage" at bottom of their pages)
  • Stephen Hawking and PBS - a variety of Strange Stuff Explained and theoretical Universes and scientists plus summaries for each of the 6 shows in Stephen Hawking's Universe and more.
  • David Darling (Internet Encyclopedia of Science) and, usually including more details (with some at a more technical level), Wikipedia beginning with a Fine-Tuned Universe.

Our Universe — Did it begin with a Big Bang?
Based on their logical analysis of abundant evidence, almost all scientists — including old-earth creationists, but not young-earth creationists who believe the Universe is less than 10 thousand years old, due to their INTERPRETATION OF GENESIS — have concluded that our universe began 13.7 billion years ago with a rapid expansion (not an explosion) that is commonly called The Big Bang.

The Big Bang !
  • This process of expansion is explained by NASA (FAQ and excellent series) and Exploratorium/CERN and Gary Felder and you can take a History Trip thru the Big Bang with text-and-animations.
  • Why the Big Bang Theory is not Irreligious by Ted Davis.  {4 k}

Inflationary Big Bang ?
Many cosmologists think the expansion of space was extremely rapid near the beginning of time in our universe, in a brief inflationary period, then the expansion slowed down to its post-inflation rate.  In this theory, inflation caused the observed large-scale “smooth” homogeneity of the entire universe;  but its overall large-scale smoothness is modified by some lumpiness on a medium-large scale because, during inflation, tiny quantum fluctuations (which were expanded to much larger scales by inflation) produced medium-scale “lumpy” inhomogeneities where the density of matter was slightly higher, and these locations were focal points for the gravitational attraction of matter, mainly star-forming hydrogen, into clusters that became stars and galaxies.
  • NASA explains inflation theory — what it is, and how it solves 3 problems (re: flatness, horizon, monopoles) of non-inflationary Big Bang theories. {4 k}
  • NASA also explains how post-inflation inhomogeneities in the density of matter, described above, would produce astronomical structures (such as our galaxy) and cause the Cosmic Microwave Background to have anisotropies (with extremely small differences in temperature when we look in different directions) that have been detected in WMAP data (which includes support for a key signature of inflation) collected by the Wilkinson Microwave Anisotropy Probe.
  • other introductory overviews of inflation, from Patricia Schwarz {11 k for two pages} and Foundations of Cosmology {4 k plus Q-and-A}.
  • for more details, a 5-page series by Alan Guth who first proposed the model of inflation {26 k total);  and Gary Felder {35 k} and John Gribbin {33 k, also describes chaotic inflation}.
  • for more depth, Gary Watson bridges the gap between popular and technical accounts in a series intended to make inflationary cosmology "accessible to undergraduates."

Some cosmologists think a process of eternal chaotic inflation did produce (and still is producing) many universes, and thus a multiverse.

What happened before the Big Bang? — scientific theories for the beginning of our universe
One type of proposal for a beginning speculate about a pre-bang vacuum that wasn't really "nothing" because, due to quantum fluctuations (due to the Uncertainty Principle in Quantum Physics), the fields in "empty" space cannot be continually zero.  Perhaps a quantum fluctuation became large enough to begin a process of inflation leading to our universe.
    • What happened before the big bang? by Paul Davies, is an introductory overview of the question, explaining how in quantum cosmology "there are physical events which do not have well-defined causes" so "nature apparently has the capacity for genuine spontaneity" that might include a Big Bang beginning without an apparent cause. {11 k}
    • What happened before the big bang? by Jack Wong, describes an overall context for the question, and the Hawking-Turok Instanton theory. {19 k for ToC and pages 1-7}
    • IOU - I'll describe the two main theories about producing a universe from "nothing" -- quantum fluctuations (with inflation) and no-boundary with imaginary time.
    • Before the Big Bang, There Was . . . What? written by Dennis Overbye for the NY Times in 2001, is an excellent overview of many speculative ideas. {19 k}  IOU - Sometime, maybe in 2016, I'll write a critical commentary, trying to add some logically appropriate humility to this fascinating collection of diverse ideas.  I'll connect it with questions later in this page — asking "is it scientific?" — and will emphasize the accuracy of a quotation from the end of Overbye's article, regarding the wide variety of conflicting theories: "none of us can claim victory."  Earlier, there is a nice analogy, comparing cosmologists with jazz musicians "collecting themes that sound good for a work in progress: ‘You hear something and you say, oh yeah, we want that in the final piece.’"  But will all of the themes fit together?  And we still should wonder about the origin of the "piece" that is the basic laws of physics.
Cosmological Inflation and Conservation of Energy 
        Although it seems that producing a universe would require producing vast amounts of matter/energy, this may not be necessary.  If the geometry of our universe is almost-flat, as predicted by theories of cosmological inflation, our universe could be produced from a small amount of matter/energy.  How?  As explained by Paul Davies, if the geometry of a universe is exactly-flat (Euclidean), then "Einsteins's theory of general relativity predicts that the universe should have zero total mass: the positive mass-energy of matter is exactly canceled by the negative mass-energy of the gravitational field of all the matter in the universe. (page 48 of Cosmic Jackpot)"  But some mass/energy would be required, except for an exactly-flat universe, so we can still wonder “where did this mass/energy come from?”
    • A Universe from Nothing {3 k} by Alexei Filippenko and Jay Pasachoff.   The Free Lunch that Made Our Universe by Lawrence Krauss. {4 k}   The Big Bang & Energy Conservation {7 k} by Mano Singham.   Creation ex nihilo - Without God by Mark Vuletic. {11 k}
    • Is the Universe a free lunch? by Paul Davies, combines ideas from inflation and quantum cosmology. {20 k}
    • -= [we'll get critiques of these proposals]

Energy & Matter, and Forces

    Einstein showed that energy and matter are related (e = mc2) and they can be interconverted.  Our universe is full of matter/energy, in elementary particles and in other forms, interacting with 4 kinds of forces, so while you're reading about cosmology you'll see the following ideas about the usual type of energy/matter (electromagnetic light-photons, and the particles that are studied in chemistry and biology) plus the mysterious dark matter and dark energy.

The Standard Model of Particle Physics, for matter/energy and forces, is explained by CERN and Exploratorium/CERN and Wikipedia (link goes to section about "Challenges to the Standard Model" - also see "Open Questions..." below) and Particle Adventure and James Schombert and HowStuffWorks and a detailed simplified summary.
  • The Standard Model of Particle Physics is usually viewed as one part of the search for a Theory of Everything, which is discussed below in String Theory Landscape.
  • Anti-Matter — from Symmetry {1 k} and CERN's Antimatter Academy {lots to explore}.  Is Antimatter Spacecraft possible?

Dark Matter & Dark Energy — from CERN {3 k} and NASA {11 k} describing matter-energy in the universe as 5% ordinary matter (atoms,...), 23% dark matter, and 72% dark energy.
  • Dark Matter — from Fermilab and -=
  • Dark Energy — is explained by Symmetry and NASA & NASA and Newsweek and Wired Science and   /   In this area of cosmology the terms and their relationships can be confusing, but they are clarified by Wikipedia: "dark energy is a hypothetical form of energy that permeates all of space and tends to increase the rate of expansion of the universe. ... Two proposed forms for dark energy are the cosmological constant ["a constant energy density filling space homogeneously" usually symbolized by capitalized lambda, Λ , in Einstein's equations of General Relativity, and "physically equivalent to vacuum energy"] and scalar fields such as quintessence ..." as discussed in their "Nature of Dark Energy" section.   /   Writing for Scholarpedia - Dark Energy by Eric Linder, and Cosmological Constant.

Open Questions (unsolved problems) in Physics
No, scientists don't yet know it all.  There are reasons for scientific and metaphysical humility.  Here are some currently-unanswered major questions, including some for the Standard Model of Particle Physics, from CERN {4 k} and a published list of 30 Unsolved Problems in Elementary Particle Physics {8 k} and explanations of The 11 Greatest Unanswered Questions in Physics {25 k} by Eric Haseltine in Discover Magazine.   Also, FreeDictionary Encyclopedia {13 k} and Wikipedia {19 k} — what is the FreeD-Wikipedia relationship?

String Theory
This is another model hoping to explain elementary particles and forces.
  • Alberto Güijosa has an excellent introductory overview of The Standard Model and String Theory {4 k} plus links {4 k}.
  • explanations by CERN and Brian Greene — in a book excerpt and interviews (short in 2010 by Discover {11 k} and longer interviews in 2003 by Nova and) and Word-IQ and Patricia Schwarz (The Official String Theory Website with 10 areas: Basics, History, Experiment, ...)  /  Controversy about String Theory — The Great Debate and
  • videos — Brian Greene, for TED and throughout Hours 1-2-3 of The Elegant Universe (video is available with brief descriptions of chapters or fuller descriptions of chapters plus written transcripts) from NOVA;  if you read what Alberto Güijosa says about the book and series ("the approach is excessively propagandistic") and his link to a review in NY Times, you'll see some of the controversy among scientists about string theory.  {-= and I may link to video-excerpts of this in youtube}

String Theory Landscape — A Theory of Everything with Many Universe-Types?
        Why is nature fine-tuned for life?  Proposals for explaining this fine tuning by anthropic reasoning (beating the odds with a multiverse) require an immense number of universe-types.  According to string/M theory * — which is not yet fully developed, but is currently popular (and controversial) in the physics community — the basic properties of nature are caused by vibrating strings of energy.  The developers of string theory want it to be a Theory of Everything or, more accurately with metaphysical humility, a Theory of Everything Physical.  But in contrast with earlier hopes for a unified theory that would explain why all observed properties of nature (the effective laws of nature in our universe) must be the ONE way they are, with string theory the properties of nature might take MANY different forms (perhaps 10500 forms, with common estimates ranging from 10100 to 101000) in a string landscape of possibilities that could produce many universe-types within a multiverse.  How?  Even if all strings in all universes were governed by the same fundamental laws of nature, if the characteristics of strings vary from one universe to another — due to differing quantum fluctuations in the early stages of different universes — this variability could produce different observable effective laws of nature in the low-energy conditions that begin within a second after a Big Bang expansion.  How? *
        The transition of conditions from high-energy to low-energy is outlined in a Big Bang Overview: "The early universe was filled... with a very high energy density. ... [then several stages later, but only 10-12 seconds after the beginning, after energy of the hypothetical inflation-producing inflaton field had been converted into familiar matter/energy] ... the temperature dropped, leading to further symmetry breaking processes that manifested themselves as the known forces of physics, elementary particles, and..."  For details you can click their links, or look at Wikipedia's history of the Big Bang (assuming inflation) in a graphical timeline and (with a caution that "all ideas concerning the very early universe are speculative") verbal timeline.
        Grand Unified Theory:  This verbal timeline describes the hopes for a Grand Unified Theory combining 3 of the 4 known forces (electromagnetic, weak, and strong) in the early high-energy conditions, and explaining elementary particles.  A broader Theory of Everything {TOE} would also include gravity, and unify quantum mechanics with general relativity, and explain all known physical phenomena.
        * terminology:  11-dimensional M-theory (with membranes & strings) was proposed in 1995, elegantly unifying five earlier versions of 10-dimensional string theory (with strings);  usually but not always (so check the context) M-theory and string theory are used as synonyms, and it can also be called string/M theory or M-string theory.
        * DNA and Strings:  Another how-question is answered, by Leonard Susskind, using analogy between a DNA landscape and string landscape, with different sets of DNA-properties (or string-properties) specifying the biological-properties (or nature-properties) in different organisms (or universes), and letting organisms (or universes) have diversity.   /   As with all analogies, there are similarities and differences between the landscapes of DNA and strings.  We know, from observation, that the DNA landscape is populated by a rich diversity of biological organisms.  By contrast, Susskind can only imagine the diverse universes in his "landscape of possibilities populated by a megaverse of actualities";  both parts of his claim (for string theory, and many universes) are disputed by other scientists because neither landscape nor universes can be observed, so are his theories unscientific?

        In addition to this possibility, with a string theory landscape, there might be other ways to produce a wide variety of universe-types to use in anthropic arguments against an intelligent design of nature.

Four Possibilities for a Multiverse
Max Tegmark asks us to imagine four possible levels of a multiverse:
    Level I Multiverse — our universe is part of a vast mega-universe (produced by inflation) containing many large spatial domains, including the one where we live, that are actualized-universes;  these are all the same universe-type, but with differing initial conditions and different developmental histories.
    Level II Multiverse — contains multiverses of many types (maybe 10500 types, with differing properties of nature)* with many Level-1 actualizations of each type.     {possible multiverse-generating mechanisms (chaotic inflation, colliding string-branes, black holes) are described below }
    Level III Multiverse — a "many worlds" interpretation of quantum physics proposes that each universe is continuously quantum-split into many independent physically-actualized universes with diverging histories.
    Level IV Multiverse — includes "everything possible" regarding universes that differ in their fundamental laws of nature, instead of just differing in their initial conditions (as in Levels 1-2) and histories (in 1-2-3), or (in 2) their low-energy observable effective laws of nature for nature's dimensions, equations, physical constants, particle properties,...

  • Jeff Zweerink says, "Max Tegmark’s multiverse overview provides a nice framework for further discussion.  He organizes all multiverse models into four different levels, with higher-numbered levels being more speculative than lower-numbered levels. ... Most of the scientifically and apologetically pertinent points arise in the Level I and Level II multiverses." {2 k for descriptions, after an introduction}
  • Wikipedia {5 k for the section about Tegmark's levels}
  • Max Tegmark explains the science associated with potential multiverses. {68 k}
    editor's comment about writing style:  Some enthusiastic advocates of a multiverse, including Tegmark, tend to boldly assert that "this IS how it is" without qualification and appropriate humility.
  • Later, a section asking "is a multiverse theory scientific?" has links to Tegmark's paper in Scientific American and a critical analysis by Karl Stephan.

        Multiverse Levels and Intelligent Design: 
        If a multiverse exists at any level(s), the implications for design depend on whether the multiverse contains many universe-types and/or many universe-actualizations, which are required for two types of anthropic arguments against intelligent design:
        An argument claiming to “beat the odds” against a design of nature requires a multiverse containing many different universe-types with different laws of nature.  This variability-of-types occurs with Levels 2 (different effective laws) and 4 (different fundamental laws & thus different effective laws) but not with 1 (same effective laws, only initial conditions differ) or 3 (all are in same universe, so nothing differs except the diverging histories) or hybrids in which the multiple history branches of 3, during formation of new universes, provides more variety for 1, 2, or 4.  But for each proposed multiverse we can ask “would it be designed?”, as explained below.
       An argument claiming to “beat the odds” against design-directed action (during the history of nature) requires a multiverse containing many actualized-universes of the particular universe-type being studied.  This would occur with all four levels of a multiverse, if they exist.  And with Levels 1, 2, and 4 the actualized-universes would have differing initial conditions, which would help produce variability in histories.

A Multiverse — How might it be produced? 
( What are some proposed mechanisms? )
How do cosmologists extrapolate from our single observed universe to the possibility of many other unobserved universes in a multiverse?

        A Multiverse and/or Intelligent Design — Divine Design of a Multiverse?
        Below you'll see a variety of proposed mechanisms for generating universes in a multiverse, and for each we can ask, “Are there reasons to suspect that this mechanism was intelligently designed?”  For example, if string theory is part of the fundamental laws of nature, then “why string theory?”  And if an inflaton field has the characteristics necessary to produce eternal chaotic inflation and a Level 2 multiverse, then “why this type of field?”  Do anthropic arguments just move the why-question up one level, from a fine-tuned universe to a fine-tuned multiverse?
• In his excellent overview of multiverse-generating mechanisms, Robert Lawrence Kuhn summarizes ideas from 8 prominent scientists he interviewed for his television series.  Near the end, you'll find (search for "paul") ideas from Paul Davies: "To get a multiverse, you need a universe-generating mechanism... [based on] some laws of physics. ... About 10 different basic assumptions of physical laws [quantum mechanics, space/time, causality,...] are required to get the multiverse theory to work. ... Where do those rules come from?  Then what about the laws or rules which impose diverse local laws upon each individual universe? ... The only thing the multiverse does is shift the problem of existence up from the level of one universe to the level of multiple universes." {1.6 k for Davies, 14 k total}
  • -= [IOU - I'll find a page by Jeff Zweerink (RTB)]
  • Multiverse Requires Right Laws by Robin Collins;  in Section 6.3.1 he describes 5 things a multiverse-producing mechanism must do, and concludes that "even if an inflationary/superstring multiverse generator exists, it must have just the right combination of laws [including string theory] and fields [inflaton, electromagnetic,...] for the production [by inflation] of life-permitting universes: if one of the components were missing or different [lacking the necessary fine-tuned coordination] ,... it is unlikely that any life-permitting universes could be produced."

        The section for anthropic reasoning ends by saying "two other possible types of intelligent design... are discussed later," and here they are:

        Do we live in a simulated universe?
        Was our universe — with the fine tuning described in the introduction and above by Davies, Zweerink, and Collins — designed and produced by natural agents?  Some scholars are discussing the possibility that we might be living in a computer simulation or lab experiment that is being “run” by natural agents who designed it.  When we're thinking about these possibilities our questions about a world-producing natural agent are analogous in some ways, but not all, to theological questions about a world-creating supernatural agent.   /   The Big Lab Experiment by Jim Holt, describes speculative ideas from Andrei Linde. {6 k}   Alan Dawrst looks at questions for science (could humans ever produce lab universes?) and philosophical ethics (if we could do it, should we?). {21 k}  Nova Spivack asks, If the Universe is a Simulation, then what? and thinks about ways to investigate our situation, to seek a rational answer when we ask “is it a simulation?” and “how should we respond?” {11 k}   Asking similar questions, Living in a Simulated Universe by John Barrow, looks at laws of nature and flaws of nature. {10 k}   And from Wikipedia, Simulated Reality {43 k}, Simulation Hypothesis {6 k}, Simulism {36 k}.   A links-page by Nick Bostrom, regarding his Simulation Argument.

        Natural-Appearing Divine Guidance
        One possibility for divine design-directed action is a natural-appearing guidance of natural process;  the result of this action would be to produce a desired natural-appearing result instead of another natural-appearing result that would have occurred without the guiding action.  Christians and other theists usually think about, and pray for, divine guiding-action now in our everyday lives.  Some theists propose that earlier, during the formative history of nature, God influenced the results of natural evolution by guiding it;  proposals for the frequency of guidance range from occasional to continual, and from influential to determinative for the strength of guidance.  But guiding could also occur much earlier in history, to affect (to influence-or-determine) the properties of nature in a universe;  this might occur, for example, if nature-properties in a universe are part of a string theory landscape and if the guiding-action affected the result of quantum fluctuations in the early stages of a universe, which affected the characteristics of strings in that universe, and thus its effective laws of nature.  Or divine guiding-action could affect the initial conditions in a universe, which would affect its developmental history.

Some questions about simulations/experiments and guiding action are examined later, when we ask is your theory scientific?

        Inflation as a Universe-Generating Mechanism for a Multiverse at Levels 1 and 2
        Inflation Model (Level 1) — The basic concepts of inflation (what it is, why it's proposed, evidence for it,...) are explained earlier.  If the process of inflation produced many other spatial domains similar to our own, this would be a Level 1 multiverse.  All of these domains would be “universes” having the same properties of nature, but with different initial conditions and thus different histories.  But if there were enough actualized universe-domains the histories might begin to “repeat” by producing nearly-identical histories, leading to questions (philosophical and theological) about duplicates.
        Eternal Inflation Model (Level 2) — Although simple inflation is supported by significant indirect evidence, proposals for chaotic eternal inflation are based only on theory.  Some theoretical models of inflation, but not others, predict that during inflation many “big bangs” occur, with each producing a new Level 1 multiverse.  Typically, single-field models of inflation (but not double-field hybrid models) predict a process of chaotic inflation that will be future-eternal, continuing forever, and if the new Level 1 multiverses have differing properties of nature (as in a string theory landscape) this would be a Level 2 multiverse;  but probably the process could not be past-eternal, so it would have to begin sometime in the past.
        Scientific details about possibilities for generating a diverse Level 2 multiverse — including more about eternal inflation (combined with a string landscape) and also ideas involving string-membrane collisions, black holes, and more — are in MULTIVERSE SCIENCE - THEORIES ABOUT MECHANISMS.

        A Many Worlds Interpretation of Quantum Physics (Level 3)
        This extremely speculative interpretation of Quantum Physics (aka Quantum Mechanics) claims that the wave function never “collapses” during a physical interaction that converts a range of possible results (whose probabilities can be calculated using the math of quantum physics) into one result that actually occurs (and therefore now has a probability of 100%) as proposed in the conventional Copenhagen Interpretation.  Instead, with a Many Worlds Interpretation (MWI) during every physical interaction of every wave-particle in the universe, every possible result actually occurs in its own separate branch of history.  Thus, with MWI during each instant of time an immense number of history-branches are produced, and during the next instant each of these branches split into many more branches, and this has continued since the beginning.  This process would produce an unimaginably immense number of history-branches where EVERYTHING happens, including each of us doing every possible thought and action, which raises difficult theological questions about MWI.
        Some scientists are fascinated by the mathematical elegance of MWI, which lets them describe the entire universe with a single mathematical wave function.  But this mental convenience requires paying a high cost in physical extravagance.
        In MWI the history-branches are probabilistic because, in order to avoid an immense violation of energy conservation, the branches cannot all be “real” in the usual way we define reality.  It's difficult to understand exactly what is being proposed.  But whatever the proposal is, a Level 3 “multiverse” is definitely different than Levels 1, 2, and 4, so there are reasons to think Level 3 should not be considered an authentic multiverse.
        With MWI all of the imagined history-branches would occur in the same universe, so there is only one universe-type and one set of initial conditions.  But anthropic reasoning requires many universe-types, so an MWI-universe is not useful for a non-design explanation of fine tuning in our universe.*  But MWI could be used to challenge claims for design-directed action during the history of nature, because with MWI everything that could happen (including a natural origin of life and all of its possible evolutionary developments) would happen in some branches of history if the only question is probability, if no laws of nature are being violated.   {*or could string theory + MWI provide a mechanism-and-explanation?}
  • A 5-page series by Andrew Thomas is a good overview of Quantum Mechanics including Quantum Decoherence which explains why he thinks "far too much is read into the so-called ‘collapse of the wavefunction’. ... the Many Worlds interpretation seems very much a product of the fifties [when we knew less than now].  Recent results in quantum decoherence have given us new insights into the quantum measurement problem, and there is no longer any need to propose parallel universes to explain the process."
  • How would Christian Theology deal with MWI? is an article followed by comments, beginning with the best.  {18 k total}
  • I.O.U. — Eventually, but not until 2016, there will be more about quantum physics in the links-page for INTERPRETATIONS OF QUANTUM MECHANICS.

        Level 4 Multiverse
        The essence of this imagined multiverse is the possibility of universes with different fundamental laws of nature.
        Max Tegmark goes far beyond this concept in his appeal for mathematical democracy, which is "a form of radical Platonism" claiming that "mathematical existence and physical existence are equivalent, so that all mathematical structures exist physically as well." (quoting Tegmark on page 118 of the multi-author book, Universe or Multiverse)   This view is an extreme minority view among scientists and everyone else.  For example, Leonard Susskind, who proposes a multiverse (which he calls a megaverse) with many universe-types that include all string-landscape possibilities, says "It's one thing to argue that theory gives rise to many possibilities for the Laws of Physics, but it's quite another to say that nature actually takes advantage of all the possibilities.  Which of the many possible environments materialized as real worlds? ... Mathematical existence is not the same as physical existence, obviously. (pg 293 of The Cosmic Landscape)"
        Tegmark says (p 118 of U or M) that his mathematical democracy "casts the so-called modal realism theory of David Lewis in mathematical terms."  Modal Realism proposes that everything we can imagine (and more) actually does happen physically, somewhere in an infinity of worlds.  Wikipedia says "the theory [modal realism] was widely considered to be too implausible to be taken literally, as Lewis urged it should be ... [and a typical response was] what Lewis calls the ‘incredulous stare’."  And regarding human motivations, "While people are concerned with what they could have done [in our world], they are not concerned with what some people in other worlds, no matter how similar to them, do."

Philosophy of a Multiverse

This part of the page includes:  Ultimate Origins and First Cause
Anthropic Principle(s) and Anthropic Reasoning
Is your theory scientific (asked for Intelligent Design & a multiverse)

-= [parallel universes & multiverses - in science, philosophy, and theology, plus science fiction books & movies, comic books, etc - the concepts can affect our thinking (if we're thinking about it, as individuals or in groups) whether or not they exist / this is worthy of exploration but won't do much here] popular media education & mis-education / human fascination with aliens -- combine this with "aliens in our universe and in other universes" questions in theology?

Ultimate Origins and First Cause — What existed, and then what happened, before the Big Bang?
        What, or who, caused the beginning of our world? and how?  What existed before the beginning of our universe or (if it exists) our Multiverse?  and then what happened?  Why is there something instead of nothing?  And why is this "something" the way it is, instead of another way?  For these metaphysical questions *, theists and non-theists propose different answers.  A non-theist assumes the existence of a materialistic capability for creating our universe (or multiverse).  A theist assumes the existence of God, who has this creative capability.  Each asks the other, "Can you explain what caused the existence of what you assume as the starting point?"  Can either offer an answer that can be proved beyond a reasonable doubt, and (in a different question) will be accepted by the other?   /   * These questions are metaphysical, not physical — since there is no empirical data about what existed and what happened before the Big Bang Beginning of our universe — so, as with multiverse questions, our thinking "can be strongly influenced by our preference for a particular [metaphysical] worldview and type of explanation."
        When we ask "what happened before the big bang?" some scientists have answered "quantum fluctuations of a vacuum" and "spacetime with no boundary."  And Cosmological Inflation explains how a universe "could be produced from a small amount of matter/energy," but not from zero matter/energy.
  • Does the Big Bang prove that God exists? is an introductory overview {5 k} by Deborah Haarsma & Loren Haarsma.
The Problem of What Exists by Paul Davies, ponders "the fundamental problem of existence: the mysterious process whereby the existent is divided from the possible-but-nonexistent. ... Who or what gets to choose what exists and what doesn’t?"  {1 k for introduction, 4 k for excerpts from "what exists?"}
  • Stephen Hawking asks, "What is it that breathes fire into the equations and makes a universe for them to describe?"  This question is examined by Matthew Kirby in God, Physics, and Stephen Hawking.  {5 k}
  • Cosmogony - The Origin of Our Universe from Word-IQ.  {3 k}
  • Maybe if we could see the beginning of our universe in a "big picture" view, with a wider perspective on space-and-time, we would see our universe as one of many being produced by a universe-generating mechanism such as chaotic inflation, colliding branes, or black holes. The beginning of our big bang might have been a quantum fluctuation, or maybe (as proposed by Hartle & Hawking) there was no beginning of space-and-time.
  • Cosmological Argument by Bruce Reichenbach, writing for the Stanford Encyclopedia of Philosophy, is an in-depth overview of arguments and counter-arguments {66 k} plus bottom-of-page links where you can learn more about the Kalam Cosmological Argument (and variations) from William Lane Craig & others, and Quentin Smith & others.

Copernican Principle (is earth special?) and Mediocrity Principle (are we special?)
        In 1543, Copernicus published his Heliocentric Theory, suggesting that we change our concept of Earth's location by mentally moving it from the center of everything to an orbit around the sun.  An extrapolation of this idea, the Copernican Principle, claims there is nothing special about the location of Earth.  This principle is supported by astronomical observations showing that, on a large scale, the structure of our universe seems to be homogeneous in all directions at all distances.  Of course, on smaller scales our location is special in some ways due to features (such as its distance from a star) that are required for the lives of intelligent observers.  Therefore, Deborah Haarsma suggests using the Weak Anthropic Principle as a modifier to revise the Copernican Principle so it says "our location in the universe is not unique when compared to the set of locations that could support life."
        In addition to this conceptual change about the location of Earth, our perception of its relative size (compared with everything else) has continued to change as our knowledge improves.  First we learned that Earth is a small planet orbiting a much larger star in our solar system, which (we later learned) is part of a billion-star galaxy, which (we later learned) is part of a billion-galaxy universe with more than 1022 stars.  And now we hear claims that our huge universe might be only one of an immense number of huge universes within a mega-huge multiverse.  Although these ideas might seem to diminish the importance of earth and humans, in Judeo-Christian theology our worth is determined not by our size, but by the value placed on us by God.
        A related idea, the Mediocrity Principle, proposes that there is nothing special about either Earth or humans.
        These principles, which begin with scientific knowledge and then extrapolate beyond it, can be used to make assertions (explicit or implicit) about science, philosophy, or theology.

IOU - we'll find and select resources for all 3 paragraphs -=
  • Wikipedia - Copernican Principle {7 k} and Mediocrity Principle {4 k} / check Word-IQ
  • source of quote by Deborah Haarsma is p 145 of the multi-author Science and Religion in Dialogue - contents/authors + excerpts & more)
  • Wintery Knight, compares the Copernican Principle with ideas from Jay Wesley Richards and Guillermo Gonzalez. {6 k} -=[page(s) from Richards and/or Gonzales also will be here]
mediocrity & science --

Anthropic Principle
        As explained above, this term is used in many ways anthropic principle can describe the life-friendly properties of nature that provide evidence for fine tuning, or interpretations of this fine tuning, or different explanations for it that propose either design or non-design.
        Weak and Strong:  an uncontroversial Weak Anthropic Principle is a tautological Selection Principle stating that we must observe nature-properties consistent with our existence;  controversial Strong Anthropic Principles claim that the Universe must have nature-properties consistent with our existence, but when we ask "WHY must the Universe have these properties?" the reason varies with the person making the claim.
        Participatory and Final:  Two other ideas, the Participatory Anthropic Principle and Final Anthropic Principle, are much more speculative, and much less often given serious consideration.

  • Anthropic Principle - Definitions & Critical Analysis from Word-IQ.  {8 k}
  • Consistent with the multiple meanings of this ambiguous term, its wikipedia page {39 k} begins by acknowledging that "the anthropic principle is the collective name for several ways of asserting that the observations of the physical Universe must be compatible with the life observed in it" and warning you that "the neutrality... in this article is questioned," as discussed in its feisty talk page;  then it describes the many definitions-with-variations and the controversies.
  • Daniel Berger offers an Impertinent Critique of Anthropic Principles that claim support for non-design.
  • Self-Location and Observation Selection Theory: An Advanced Introduction by Nick Bostrom.  {40 k}

Should scientists use Anthropic Reasoning?
        Although the Weak Anthropic Principle is logically valid, it becomes controversial when it's used in anthropic reasoning to explain fine tuning.  When we ask is anthropic reasoning (with a multiverse) scientific? there are two common objections:
        Type of Explanation — Some physicists want to find a unified Theory of Everything that will explain why there must be one way for nature to be, instead of the many ways proposed in a string landscape.  This preference, by an individual or community, can be aesthetic (if a one-way theory is viewed as being more elegant) and practical (in a perception that a many-ways theory might hinder a search for a one-way theory that is their goal).  This preference for a one-way theory can extend to a preference against anthropic reasoning when it uses a many-ways theory to claim the many universe-types that are required for anthropic explanations of fine tuning.   /   But if scientists eventually find an elegantly unified theory explaining why the properties of nature must be the way they are, and this one way is “just right” for life, wouldn't this coincidence lead them to suspect an intelligently designed universe?  Or would some of them say "no choices were necessary, or even possible, so there could be no design"?
        Motivation — Some advocates of intelligent design claim that multiverse proposals are not warranted by scientific evidence-and-logic;  instead, the main motive for proposing a multiverse is that it allows anthropic reasoning in arguments against an intelligent design of our universe.  This claim is examined in the following section.

Motives and Worldviews in Evaluation
        In what ways, and to what extent, are evaluations of a multiverse influenced by motives associated with worldviews?
        Motives and Evaluations:  Theists who want to “win arguments for God” by claiming divine designs, before and during history, have a motive to oppose a multiverse that can weaken their claims.  To avoid losing these arguments, atheists (and others, including rigid agnostics) have a motive to defend a multiverse so they can maintain their worldview-beliefs.  A multiverse seems necessary for atheism, but a multiverse might be divinely designed so it would not be proof of atheism, or even strong evidence.  Those who just want to find truth, including some theists and non-theists, can try to objectively evaluate the pro-and-con arguments from science, philosophy, and theology.  But this may be difficult because...
        Worldviews and Evaluations:  Several theories, proposing design or non-design in a universe or multiverse, seem plausible.  None of these theories can be proved or disproved persuasively, using science or in other ways, so our evaluations of these theories can be strongly influenced by our personal preference for a particular WORLDVIEW.
        Evaluations can also be influenced by other factors, including views about the Interactions of Observations and Theory in science, and (as explained above) preferences for a particular type of explanation.

Is your theory scientific?
        To explain the fine tuning of nature in our universe, two main types of theories are proposed:  intelligent design (of a single-universe or multiverse-universe) and a multiverse (either designed or non-designed).  Advocates of both theories, proposing design and/or a multiverse, must defend their view against critics who say "your theory is not scientific."

        Can a DESIGN THEORY be scientific?
        Instead of trying to answer this question generally, we should think specifically about FOUR TYPES OF DESIGN THEORY:
    If natural-appearing guidance is defined as undetectable guidance, then a design theory proposing natural-appearing guidance by God will be a theological claim, not a scientific claim, because any natural-appearing guidance would be scientifically undetectable (by definition) even if the guidance produced a goal-result that was wanted by God.
    The scientific detectability of design-directed action by a natural agent is not controversial, because everyone agrees that this is possible and is common in science.
    But the scientific detectability of design-directed action by a supernatural agent is controversial because:  when we look at design in biology (the area where design-claims are usually made) the capabilities and limitations of natural evolution are not fully known;  and we know much less, compared with our knowledge of familiar natural agents, about the intentions and capabilities of a supernatural agent;  another factor is methodological naturalism, as discussed below.
    The main question in this page is a design of nature-properties in our universe, and currently there is no unquestionable answer so humility (scientific and metaphysical) is appropriate.   Because there might be an inverse relationship between perceived plausibilities for agency-explanations and mechanistic-explanations, questions asking "is a multiverse theory scientific?" are relevant when we ask "is a design theory scientific?"   For interesting perspectives on philosophy, methodology, and sociology, we can compare theories proposing universe-design by natural agents (as in a physical experiment or computer simulation) and by supernatural agents:  How are these proposals for alien design and divine design treated in the community of scientists?  What are the similarities and differences, and what reasons are given for any differing treatments?  What kinds of scientific analyses are suggested for questions about alien design? Could any of these also be useful for thinking about divine design?
        In general — and then we can make specific adjustments for each type of design question — the scientific authenticity of design theories is criticized in two main ways.   First, there are methodological similarities and differences between a mechanistic theory (as in a theory of non-design) and agency theory (as in a theory of design);  if the criteria for "being scientific" are defined by using a mechanistic theory as the standard, an agency theory will fail to meet some of these mechanistic criteria.   Second, although a basic design theory claims only that design-action did occur, and does not explicitly propose supernatural action, it does allow supernatural action so it implicitly violates the criterion of methodological naturalism.   INTELLIGENT DESIGN IN SCIENCE?

        Methodological Naturalism in Science
        With methodological naturalism a scientific theory must propose only natural cause-effect interactions in the history of nature.
        When this restriction is used in historical science, it disqualifies any inference to supernatural intelligent design, either before or during history, so scientific explanation equals naturalistic explanation.  Therefore, if a multiverse theory is the best naturalistic explanation for fine tuning of our universe, it automatically becomes the best scientific explanation;  in this way, direct evidence for fine tuning can be claimed as being indirect evidence for a multiverse theory.  Ironically, a naturalistic assumption can convert the strong evidence for a fine tuning of our universe into evidence against its design as a single-universe, although not against its design as a multiverse-universe because a multiverse could be designed.   METHODOLOGICAL NATURALISM IN SCIENCE?

        Can a MULTIVERSE THEORY be scientific?
        Observation-based empirical testing is the foundation of scientific method, but we have no direct observational evidence for other universes.  Therefore, some scientists (and other scholars) claim that multiverse theories cannot be tested using the commonly accepted methods of science, and do not meet the accepted standards for science, so these theories are philosophical speculations rather than science.
        Direct Support from Observations:  Well, there isn't any.  But if other universes could not be observed even if they existed, is their non-observation neutral, counting neither for nor against a multiverse theory?  If not, where should we place the burden of proof or disproof?
        Indirect Support from Observations:  The logical foundation of modern science is hypothetico-deductive logic, which permits a theory to propose unobservable entities if these help the theory explain observable outcomes, either by theory-based predictions (of future observations) or retroductions (of already-known observations).  Almost all scientists accept modern scientific theories that propose unobservable entities — such as electrons (in chemistry) and ideas (in psychology) — if these theories provide the most satisfactory explanations for our observations.  Usually, the explanatory success of a theory is viewed as indirect evidence for the existence of unobservable entities in the theory.   /   an application:  A currently popular multiverse theory (string landscape) proposes that many faraway universes {all unobservable} have a wide range of nature-properties {all unobservable} caused by tiny strings {unobservable even in our universe} with a wide range of string-properties {all unobservable}.  Do we have now, or could we have in the future, significant indirect evidence for (or against) any of these proposed entities, or all of them?  These questions are being vigorously debated by scientists and other scholars. 
        Mechanism:  Maybe the cause of our universe also caused other universes.
        Motivations and Explanations:  Two objections to anthropic reasoning are a suspicion that multiverse theories are motivated mainly by a desire to avoid a conclusion of divine intelligent design, and a preference for explanations that propose one way for nature to be, not many ways as in a string landscape.  In a related question we can ask, “Does a multiverse theory (or atomic theory?) lack scientific simplicity because it proposes zillions of entities, or should we focus on theory structure and other criteria for elegant simplicity?”
        And the complexity of the discussion increases when we evaluate different multiverse theories (there are several competitors plus variations) and we are wondering about theories (such as string theory and eternal inflation) that are components of some multiverse theories.

  • A condensed outline {4 k} of ideas for a conference about Philosophy of Cosmology: "The very nature of the concept of science is being challenged by cosmological proposals [proposing a multiverse] that appear to be becoming mainstream. ... In this context a variety of theoretical and observationally or experimentally related arguments have been given for the existence of a multiverse, that in essence amount to a claim that we should weaken the usual requirements for verification of scientific theories that underlie the success of the scientific project over the past 300 years."
  • The Anthropic Principle: Intelligent Design and/or Multiverse? by Craig Rusbult, describes arguments based on direct evidence, indirect evidence, related cause-and-effects, fine tuning, naturalism, two types of explanation (with one possibility or many) and philosophical preference, plus (in a later section) Occam's Razor.  He thinks that instead of eliminating multiverse theories from serious consideration by saying “they aren't scientific” we should patiently learn, critically evaluate, and use appropriate humility to estimate a level of confidence (somewhere between rejection and acceptance) for these theories.  {10 k total for these sections} 
  • Descriptions of possible observational support for a multiverse are in Science's Alternative to an Intelligent Creator: the Multiverse Theory on page 3 where the link takes you.  Notice the two bold claims in this title, which states that a multiverse theory is scientific but a design theory is not scientific, and answers “no” when we ask was this multiverse-generating mechanism intelligently designed?

Controversies about String Theory:  Is string theory — which is a key component in two current models of a diverse multiverse — scientifically unverifiable?  in what ways is it scientific?  and what resources (intellectual and financial) should the scientific community invest in it?  These are among the questions in two books from 2006, The Trouble with Physics by Lee Smolin, and Not Even Wrong (click Editorial Reviews, 4k) by Peter Woit who is an outspoken critic of string theory (2k for Critics... + String Wars).  You can explore their ideas in a review of Smolin's book by Sabine Hossenfelder (9k, plus links to other reviews including one by Woit, and blog-responses) and associated comments by Smolin (10k).
  • Briane Greene says, "Falsifiability for a theory is great, but a theory can still be respectable even if [as seems possible for string theory] it is not falsifiable, as long as it is verifiable. There are aspects of a theory that you can go out and look for and confirm, and that’s another way to gain confidence in it. For instance, it’s really hard to falsify the statement that there is life on another planet, but you can verify it by finding one example. We’re hoping that certain features of string theory are confirmable." (interview in 2010)   In an article, Greene defends string theory (on page 3 where this link takes you) because it "continues to offer profound breadth and enormous potential" and "we will hold string theory to the usual scientific standard: to be accepted, it must make predictions that are verified." {3 k for page 3, and 12 k total}
  • Multiverse Mania (with some current entries + a link for Older Entries) is part of the "Not Even Wrong" blog by Peter Woit, vigorously criticizing string theory and associated multiverse theories.
  • Falsifiability in Physics is a defense of string theory {20 k} by Luboš Motl, but Michael Riordan explains why he thinks "string theory is not really a ‘theory’ at all" in his review of Smolin's book {6 k} for Physics World.
  • The Smolin-Susskind Debate began in 2004 when Lee Smolin said "the Anthropic Principle cannot yield any falsifiable predictions, and therefore cannot be a part of science," and he asked Leonard Susskind to respond.  {76 k}
  • Leonard Susskind discusses a multiverse and one controversial aspect of string theory — should scientists prefer one way for nature to be, or many ways — in an interview with American Scientist in 2005. {10 k}   /   In a review of Susskind's book, The Cosmic Landscape, George Ellis asks "How can this be a scientific proposal?" and explains why he is skeptical, despite the confident enthusiasm of Susskind. {8 k}

  • IOU — Later, we'll have web-resources with different perspectives on the question, "Can theories proposing an intelligent design of nature be scientific?" to supplement the brief introduction.

  • Casey Luskin thinks Multiverse Proponents Hide Their Philosophical Motives: "This speculative [multiverse] idea was invented for the purpose of avoiding the conclusion that the cosmos was intelligently designed." {9 k}   /   And he examines The Double Standard for Testability in a Design Theory and Multiverse Theory by comparing the claims of multiverse advocates like Leonard Susskind who thinks "it would be very foolish to throw away the right answer on the basis that it doesn’t conform to some criteria for what is or isn’t science” and Luskin asks, "Has the scientific community given ID proponents the courtesy given to Dr. Susskind? ... Perhaps untestable theories are acceptable... when they can challenge intelligent design, but are not acceptable when they support design."  {4 k}
  • "Our Universe: Outrageous Fortune" by Geoff Brumfiel, looks at multiverse theories and asks, "Are these harmless thought experiments, or a challenge to science itself?"  Although some quotes are in Luskin's "Double Standard" page above, the entire article is available only for subscribers to Nature, which includes many libraries.

  • The Multiverse Concept by Michael Heller, looks critically at multiverse methodology: "The aim of the paper is to put some criticism into the multiverse idea. Such a criticism is especially necessary when the considered topic evades empirical control. ... The crucial point is whether the multiverse hypothesis is empirically falsifiable or not. We show that the positive answer to this question is often based on a false understanding of the falsifiability criterion."  {19 k}
• Max Tegmark (who thinks four possible types of multiverse are probably real) claims that Parallel Universes are "not just a staple of science fiction; other universes are a direct implication of cosmological observations" and he explains, throughout the paper and especially in the final section, why he thinks multiverse(s) existence is supported by science. {35 k}   /   Parallel Universes: A Challenge to Intelligent Design? by Karl Stephan, analyzes this paper and concludes that "Tegmark’s arguments in favor of multiverses, far from being ‘empirical science,’ are shot through with philosophical presuppositions which cannot in principle be verified by observations." {35 k}
• Wikipedia's Theory of Everything explains what a TOE might be in the context of an "expected pattern of [GUTs and gravity] theories," why "a small number of scientists claim that Gödel's incompleteness theorem proves that any attempt to construct a TOE [or to know it is a TOE] is bound to fail," and (discussing the "potential status of a theory of everything") why "no physical theory to date is believed to be precisely accurate. Instead, physics has proceeded by a series of ‘successive approximations’ allowing more and more accurate predictions over a wider and wider range of phenomena." {22 k}
  • A pro-multiverse analysis of scientific & philosophical arguments from Jim Holt. {10 k} -=[find more about godel?]
  • Multiverse and the Limits of Physics by Richard Easther, argues that by contrast with a generic multiverse, specific multiverse models, each based on well-defined cosmological theories, can be "confidently albeit not definitively evaluated using conventional theoretical and observational techniques." {23 k}
  • The Statistical Universe by Raphael Bousso, describes concepts ranging from inflation to string theory, and explains his research on probabilistic logic in a multiverse.  {12 k}
  • I.O.U. — Later there will be more web-resources here.

Probabilities and Infinities — for Intelligent Design or Duplicate Histories
    When asked "how big is the multiverse you propose," its advocates often say “infinitely large” and then use this claim for anthropic reasoning against design and for speculations about duplicate histories.
    For an argument based on anthropic reasoning to be considered successful, the probabilistic resources (in a single-universe or multiverse-universe) must be large enough to overcome any improbabilities — regarding either a fine tuning of nature or an improbability of evolution, which are labeled #1 and #2 in my section about anthropic reasoning — that might require design-directed action.

    Can we use conventional mathematical logic with infinities?  No, because mathematical operations with infinities lead to many strange non-intuitive results.  For example, infinity divided by 2 = infinity, infinity multiplied by 2 = infinity, infinity plus 2 = infinity, infinity minus 2 = infinity, and infinity minus infinity (or infinity divided by infinity) can equal anything from zero to infinity.
    In a similar way, conventional probabilistic logic often fails.  When we ask a question that is probabilistically preposterous — "In an infinite multiverse, what is the probability that ‘you’ — defined as a person with the same physiology as you in every detail (every molecule of DNA, protein, water,...) with all of the same experiences and memories, etc) in an identical universe (with all elementary particles in the same locations and energy-states) — will win a million-to-one lottery 100,000 consecutive times, somewhere in this multiverse?", the answer is that "your multi-win sequence will occur an infinite number of times, in an infinite number of universes."  Obviously, an infinite multiverse would wreak havoc with many types of probability-based reasoning, including scientific questions about the history of nature for anything that is anthro-essential (that is necessary for our existence) including evolution or, more generally, for the history leading to anything we have observed.  But for most scientific questions, the fact of limited observation would allow conventional probabilistic logic and scientific reasoning.

I.O.U. — This topic (thinking about infinities in speculations and reality, from the perspectives of mathematics, philosophy, physics, and theology) needs more work, re: what will be said and where (in this section and the two sections that follow) and what pages will be linked-to.

    Can infinity be physically actualized?
    As explained below (in concept #2 for thinking about duplicates), immensity ≠ infinity, and a potential infinite is not an actual infinite.  One argument against an infinite multiverse is the requirement for a physical beginning sometime in the past because a finite amount of time makes it impossible for a physical mechanism to produce an infinte number of universes.  Advocates of an infinite multiverse seem to ignore the difference between immensity and infinity.  Even if future-eternal inflation (which is proposed in some speculative physical mechanisms) produces an exponentially increasing number of universes, this would be an immense number, not an infinite number.  And immensity avoids the mathematical absurdities of infinity.
  • The authors of "Multiverse and Physical Cosmology" (George Ellis, Ulrich Kirchner, William Stoeger) examine practical questions;  their abstract says, "the issue of testability underlies the question of whether multiverse proposals are really scientific propositions," and "major problems arise in terms of [physically] realised infinities" as explained in their section {7 k} about Problems With Infinity
  • These authors (Ellis...) also encourage rational hard-nosed thinking in distinguishing between "the collection of all possible universes, and ensembles of really existing universes that are essential for an anthropic argument";  they want more mathematical accountability in estimating the actual number of universe-domains "so that probabilities can be calculated."  Because the foundation of anthropic reasoning is statistical, numbers are needed.  It seems a bit sloppy and unscientific to simply declare that everything will happen if the multiverse is infinitely large, but this is a common claim.  For example, in Parallel Universes Max Tegmark states that "in infinite space, even the most unlikely events must take place somewhere. There are infinitely many other inhabited planets, including not just one but infinitely many that have people with the same appearance, name and memories as you, who play out every possible permutation of your life choices."  Instead, scientists should ask "how many?" and try to answer with scientific estimates for the actual number of universes when we're thinking about the science, philosophy, and theology of duplicates and intelligent design.  And they should seriously consider the possibility that this number is just 1, which is the number of universes we can actually observe.
  • William Dembski, focusing on design, asks "what level of improbability must be attained before chance can legitimately be precluded?" in Chance of the Gaps.  He suggests a useful guideline: "Statistical reasoning must be capable of eliminating chance when the probability of events gets too small.  If not, chance can be invoked to explain anything."  He challenges the foundation of anthropic reasoning by arguing that "probabilistic resources imported from outside the known universe" should be avoided (*), and "only probabilistic resources from the known universe may legitimately be employed in testing chance hypotheses."  Along with many other scholars, he questions the scientific legitimacy of using reasoning that "multiplies probabilistic resources in the absence of independent evidence that such resources exist."  And overall, "While I readily admit that these inflatons propose solutions to important problems, I will argue that [when all things are considered] the costs of these solutions outweigh their benefits."   * Usually anthropic reasoning is used to argue against a design of nature, but immense probabilistic resources also have been invoked to explain the origin of life.
  • The Multiverse, Intelligent Design, and Science: Much Ado About Nothing by Jim Manzi, -=[popper's example violates "most likely to be observed" principle, and repeated observations of regularities? so his example would be rejected by scientists and thus it isn't a good example]
  • How many universes are in a multiverse?  Maybe 101010,000,000, according to calculations by enthusiastic advocates of a chaotic inflation multiverse, Andrei Linde and Vitaly Vanchurin.  Although 1010^10,000,000 is extremely large, it isn't infinite.  This attempt to estimate a number is one step in a useful direction, and the process of estimation (the model, its assumptions,...) should be critically examined to evaluate the plausibility of the estimate, to decide if it's far from reality, or if it seems reasonable if we assign suitable error bars. -=[think about precision vs accuracy, because the number might be totally off (not just quibbling about details of the last few digits)]
-= web-searching [linde vanchurin "How Many Universes Are In The Multiverse"] gives many articles — a positive report and philosophically critical or scientifically critical — so selection is necessary;  and, of course, some post-article comments are more valuable than others, so readers must wade through the garbage to find the gems, so it would be great to find an article devoted to a high-quality critical evaluation
They limit the number to --- due to limits on human observational capacity, but the actual number we're likely to observe is... zero, because other universes are unobservable, in principle (due to limits imposed by the speed of light) and also in practice.

-= [Are these estimates, for an infinitely large universe, logically plausible and scientifically justifiable?]

Boltzmann Brains -=[editor's comments: I've heard about this topic, but I don't yet understand why it should be taken seriously, IF (as I think is true) the probability of a BB significantly decreases when a BB observes a complex highly-ordered environment with a long history of development, and continues to observe this situation for years [if we reject solipsistic "memories created an instant ago" scenario] which is an extremely long period of time for a random-BB to exist without a rational cause in physics.] / [Or maybe I've already concluded that it should not be taken seriously. Probably there will be a little about BBs, here or elsewhere in the page, but there won't be much because it doesn't seem to deserve much attention.] [And I'm wondering "what apologetic or theological significance do BB-questions have?" anyway.]

Intelligent Design-Action to supplement Evolution?
If our universe is not life-producing (but is only life-allowing) the existence of intelligent life will require design-directed action during history, but a multiverse could weaken claims that design-action is indicated by scientific evidence.  In the most extreme case, when an infinite multiverse is assumed, every event that possibly could happen (no matter how improbable the event is, as long as it does not violate any non-probabilistic laws of nature) will happen somewhere at some time.  And if this event is anthro-essential, if it's necessary for the existence of intelligent observers, anthropic selection becomes important.
        Most scientists are confident that natural astronomical evolution (plus geological evolution) and biological evolution were sufficient to produce our planet and its intelligent life.  Proponents of intelligent design usually agree about astronomical evolution (the main focus in this page about design of the Universe) but they question the sufficiency of totally natural biological evolution.
        Proponents of both design and non-design agree that, of all the evolutions, chemical evolution currently has the least scientific support, although only advocates of intelligent design propose that design-directed action was required for the origin of life.  But one advocate of non-design has proposed that a natural ORIGIN OF LIFE BY "CHEMICAL EVOLUTION" ABIOGENESIS is so extremely improbable that it required an immense number of actualized-universes, within a multiverse, before it would happen:
    • Paul Nelson, an advocate of intelligent design, briefly {3 k} describes the proposal for a natural origin of life in a multiverse — because "REALLY Big Numbers Solve the Problem of the Origin of Life - and Hence, There’s No Need for Design" — in the following paper:
    • Eugene Koonin claims that although a natural origin of life is highly improbable in our universe, in a multiverse it would be probable and would occur somewhere (and here is where it happened!), in a proposal that "leaves no room whatsoever for any form of intelligent design."  You can read Koonin's abstract and paper, plus comments (by four referees & the author) in HTML or PDF.  {89 k + 4k appendix}
    • In a critical analysis of Koonin's paper, Casey Luskin explains why he thinks Philosophical Objections - Not Science - Guide Origin of Life Research.  {5 k}
    • Craig Rusbult examines a multiverse and intelligent design generally, and especially for an origin of life.  {49 k for Introduction and Part 2}
    • I.O.U. — Later, there will be more in this section, including links to pages with multiverse-based arguments against design claims.

Living in a Multiverse — Questions (in philosophy & theology) about Duplicates
        If someone claims that in an infinite multiverse EVERYTHING would happen and that would be strange, we should say "wait a minute" and put the strangeness into perspective:
        1. Speculations ≠ Reality:  Always remember that a multiverse is speculative so for everything below you can think "IF a multiverse exists, then..."
        2. Immensity ≠ Infinity:  The mathematical consequences of infinity are strange, but an immense multiverse (where many things happen) is not an infinite multiverse (where "everything" happens).  And is an infinite multiverse physically impossible?  William Lane Craig thinks "we need to understand the difference between a potential infinite and an actual infinite: ... a potential infinite is a collection which is increasing toward infinity as a limit, but never gets there" and "an actually infinite number of things cannot exist. (italics added)"
        3. Normal Observations:  In an immense multiverse you would observe things the same way you do now, as one creature living in one universe, not as an omnipresent super-observer who sees all that is happening.  And in any universe of our type, observers would rarely see highly improbable events (like a perpetual motion machine) because in each universe whatever is most likely to happen is what is most likely to be observed.*  The strangeness of a multiverse is only in your imagination;  in your actual experience nothing would be different.   /   an example:  If a multiverse includes genetic duplicates of you in other worlds, you would never meet them so this is not a cause for observational strangeness or philosophical concern.
        * Due to ou limited Observations, anthropic reasoning can be used only for things that are anthro-essential (necessary for our existence) although the logic is similar, but not identical, for anything we have observed.  Rational observation-based science would be possible in a multiverse-universe;  in fact, it would be almost the same as in a single-universe.  But one important difference would occur when we ask if design-directed action was necessary to produce anthro-essential features such as the first life.
          4a. Normal Accountability:  This is closely related to Normal Observations in #3 above, and the logic is simple.  Even if duplicates do exist (and they may not), each person can only observe their own here-and-now situation, so each person is morally responsible for the ways they respond (with their own thoughts and actions) to their own here-and-now situations.  Therefore the same kinds of judgment criteria — re: the thinking-quality & action-quality in what we think & do — could be used by God in a universe or multiverse.  {more}
        4b. No Accountability?  But the “context of duplicates” would be different in a Level 3 multiverse as proposed in a Many Worlds Interpretation (MWI) of Quantum Physics.  MWI claims that in every here-and-now instant, each of us thinks & does EVERY POSSIBLE thought & action (this is different than Levels 1, 2, and 4, where each person does ONE action), thus producing an immense number of divergent branches of history.  MWI converts a single universe (as defined in Levels 1,2,4) into a multiverse of histories.  In each "universe" everything that could happen actually does happen, somewhere else.  Because of this, an MWI-multiverse would lead to serious theological challenges for accountability and judgment.  How?   • accountability: If with MWI you think-and-do EVERYTHING, then in some branches your actions are very good but in other branches are very evil, and in some history-branches you accept the salvation offered by God but in other branches you reject it, so which “history of you” would be evaluated by God?   • sovereignty: If in MWI every possible history occurs, including many MWI-branches with horrible evil and suffering, and if there is no control by God (thus eliminating the Divine Sovereignties in #5), this total absence of control seems to be theologically unacceptable.
        5. Divine Sovereignty:  A Judeo-Christian theist should believe that in an immense multiverse, the many things happening (in different universes) would include only what God allows to happen within each universe.  Life will occur only where God miraculously creates it or (if life naturally evolves) permits its survival, so life might exist only on earth, or also in many other locations within our universe or in other universes.  And the quality of living (re: conditions, ethics, etc) would include only what is allowed by God.  Theists should not accept atheistic interpretations implying that miracles are impossible or must be unnecessary, or that "natural = without God" so there is no divine supervision or capability for control.  Instead, we should formulate our own theistic interpretations of a multiverse, analogous to our THEISTIC INTERPRETATIONS OF NATURAL PROCESS AND EVOLUTION.
        6. Appropriate Humility:  As part of our theological perspective, we should humbly acknowledge that God's method of creating our world was wise, whether or not it's part of a multiverse.  And if a multiverse exists, then if God understands the many things that might be happening, and approves, that should be sufficient for us, whether or not we understand or approve.  But humility toward God is compatible with vigorous-yet-respectful discussions where each of us explains (using ideas from science, philosophy, and theology) why we think a particular view is most likely to be true.

These questions, about duplicates and histories, are discussed below (in Probabilities and Boltzmann Brains and Simulations) and later in Theology, but they can be asked by everyone (not just theists) so they are also relevant for Philosophy in the section above.  The two sub-sections are somewhere between, so they're covered before the theology section begins.

Twins and Duplicates:  If a multiverse includes genetic "duplicates" of you in other worlds, would that be a cause for concern?  No, because you can think "this is not a problem" if you think that God approves of identical twins, and holds each accountable for their own thoughts and actions.  If actual twins (living together in the same family) are not a theological problem, potential duplicates (living independently in other worlds) are also not a problem;  if duplicates exist (and they may not) each is morally responsible in their own here-and-now situation.

Theology of a Multiverse

Christian Apologetics — Proof and Faith
      Although a multiverse may have theological implications a major concern of some Christians is an apparent decrease in the strength of one apologetics argument (to defend the rationality of Christianity) if multiverse-based anthropic reasoning is used to challenge claims for a divine design of the Universe.   { Although anthropic arguments can also be used against claims for design-directed action during history, the usual target is claims for an intelligent design of nature before history, which is the type of design that is claimed by all Judeo-Christian creationists, whose views span the entire range from old-earth evolutionary creation through old-earth progressive creation to young-earth special creation. }   Analogous reasoning, to oppose design in order to strengthen non-theistic apologetics, can provide motivation to propose a multiverse.
      Logically, the weakening of one type of evidence for God's existence (or activities) would not mean that God does not exist, or that other evidence cannot be found.
      When we ask "is there persuasive evidence for the existence and activities of God?", after a logical evaluation of all available evidence (scientific, historical, first-hand personal, second-hand interpersonal) should we expect proof or disproof, justifying a confident answer of YES or NO?  One view is in our links-page for INTELLIGENT DESIGN IN SCIENCE & SOCIETY: "God seems to want a ‘balance of evidence’ so we have some evidence (personal, interpersonal, scientific, historical) for and against various worldviews, but there is no proof.  Therefore, each of us has freedom to choose what we want to believe (which is influenced by how we want to live) and the lack of certainty forces each of us — no matter what we believe in our unique personal worldview — to live by faith in what we believe."  And you'll find links to pages asking "Can we be certain?" and answering "there is no proof, but evidence does exist" in CHRISTIAN APOLOGETICS AND POSTMODERN RELATIVISM.

There are some connections between apologetics (above) and theology (below) but in most ways they are different.  One area of overlap is described in the introductory summary: "Although controversial questions about a multiverse could affect some of the ways we think about some ideas [as described below], the practical effects on everyday living will be minimal if Christians don't let these questions decrease our ability to live by faith."

Theology in a Multiverse —
Is a multiverse theologically acceptable?

Humility in Creation Theology
    Should we avoid unnecessary restrictions on creation theology — as in earlier battles against a sun-centered solar system, and current fights against an old universe & earth — by only making claims that are necessary, based on what the Bible clearly teaches?  Does the Bible have any clear teaching about the possibility of a multiverse?
    When we see an argument for or against a multiverse, we can ask about its foundation:  Does the argument seem to be based on explicit biblical teaching or implicit biblical principles, church tradition, apologetics motivation, extra-biblical philosophical doctrine, personal aesthetic preferences, or some mixture of these?  (For many of these, extrapolation and adaptation is needed to fit the unusual new context.)
    The most common creation questions are what happened during the history of nature, but we can also ask about a design of nature, or the ultimate origins of our universe.

Christian Responses to Multiverse Theories
  • Nathan Schreider, writing for Seed Magazine, looks at The Multiverse Problem and why some prominent Christian scientists and philosophers think it is not a problem: "Is theoretical physics becoming the next battleground in the culture wars? not according to some theologians and scientists." {8 k}   The Pluralistic Universe by Schreider, is similar but with more topics in more depth, and a wider range of views that include non-Christians. {21 k}
  • Mike Duran asks "Multiverse Theory — Apologetic Tool or Atheist Construct?" and other questions. {3 k}
  • Does God So Love the Multiverse? by Don Page. -=[quote part of conclusion] {53 k} also powerpoint & audio from Wheaton symposium
  • Giordano Bruno, who proposed that a multitude of inhabited worlds exist, was executed for heresy by the Catholic Inquisition in 1600.  But according to a Catholic Encyclopedia he "was not condemned for his defence of the Copernican system of astronomy, nor for his doctrine of the plurality of inhabited worlds, but for his theological errors, among which were..." {8 k}   But you can find many admirers of Bruno who think he was a martyr for science, who keep their focus on his scientific views: #1 #2 etc. {2 k, 9 k}   Even though Bruno was not a martyr for science {9 k} his execution is sometimes cited as an example of conflict between science and religion {6 k + 6k} in popular misconceptions about the myth of science-religion conflict. {20 k}
  • Is Anybody Out There? by George Murphy, re: theological implications if life exists on other planets in our universe. {7 k}   How Many Worlds? by George Murphy {8 k} / -=[split these? separate-yet-related questions of alien life within our universe, and life in other universes]

• I.O.U. - Compared with the science and philosophy sections, this section on theology currently needs more developing and improving.  Eventually, but probably not until 2016, it will be improved overall, and there will be more resources here, including some for the views of Robin Collins (6 options I'll select from), Gerald Cleaver, Robert Mann, Bruce Gordon, and others.
  • Science & Faith in a Multiverse by Kimberly Roots, writing for Science & Theology News, is an overview of science and philosophy (from non-theists and theists) plus a little theology.  {11 k}

  • John Leslie, in the Stanford Encyclopedia of Philosophy, provides a summary of interpretations and arguments. [cosmology/theology?]
  • Paul Davies, re: natural agents producing a universe: "transcendent designer, creator, sustainer, and potential destroyer, plus miracle-worker, thought-knower, and receiver of prayers."

Questions about Duplicates
Some principles for thinking about potential duplicates are in the transition-section between philosophy and theology because it's a potential concern for a wide range of people, including both non-theists and theists.
  • A Fine-Tuned Critique of William Lane Craig by Luke Barnes, shows the logical error of claiming that "a multiverse can be used to explain anything," including a "dirty cheating texan" who always deals 4 aces to himself. {5 k}   As stated in the principles above, "in each universe whatever is most likely to happen is what is most likely to be observed."
  • Two Views:  Robert Mann explains the science of a multiverse & philosophical perspectives, and asks questions about theology — "Does God create (by whatever means) whatever can be created, or does the Creator make particular choices? ... Are there theological criteria for drawing a line, even tentatively, between the possible [with "everything" happening in an infinite multiverse, according to some claims] and the existent?  If so, what are they?  If not, can theology have anything useful to say about the multiverse?" — and scientific rationality, in PSCF articles from 2005 and 2009, Inconstant Universe {44 k} and The Puzzle of Existence {46 k}   /   In a response to Mann's 2009 paper - Multiverse Interpretation: Christian Theology and Scientific Rationality - Craig Rusbult suggests that we put the strangeness into perspective, in the ways explained above, and concludes that most proposed multiverses (all except a Many Worlds Interpretation) are compatible with Bible-based Christian theology.  {Part 1 has 43 k for the introduction and responses, plus 8 k in quotes of Mann}

  • IOU — more pages (and perhaps sections) will be here later

Fine Tuning — More Evidence and Explanations
This section is an extension of the introduction which summarizes the evidence for fine tuning, and evaluates proposed explanations.

IOU -- this section is underdeveloped, it needs more resources and more selectivity.

More about the Fine Tuning of Nature
  • Robert Newman describes three ways (in chemistry, environment, and forces) that our universe has "the right stuff" for life, and proposes a simple explanation: A Designed Universe.  {16 k}
  • The Designed "Just So" Universe - Walter Bradley looks at design from an engineering perspective, and examines three aspects of nature: mathematical form, physical constants, and initial conditions.
  • -=[IOU - we'll also get a YEC view, re: how they treat fine tuning, since much of the evidence is astronomical & about the big bang]

  • An overview-outline for many topics: The Anthropic Principle & Quantum Cosmology (maybe start with Section 2.3?) is Part 3 of a 6-part series on Physics and Faith.  {18 k}

Fine-Tuning for Earth and its Solar System
  • Hugh Ross lists properties needed for life — 34 for properties of nature, and 66 for properties of earth (and its context: galaxy, solar system, sun, moon) — and gives rough estimates for the improbability of the earth-properties (not even including nature-properties) happening by chance without intelligent design.  {24 k}   /   Hugh Ross looks at Astronomical Evidences for the God of the Bible.
  • The Incredible Design of the Earth and Our Solar System by Rich Deem.
  • Does the earth have properties that make it especially suitable as a location for life?  an interview with astrophysicist Guillermo Gonzalez by Benjamin Wiker.

Intelligent Design and a Multiverse
  • Ted Davis, in a review of God's Universe, explains why Owen Gingerich (author of the book) thinks it "takes faith to draw this conclusion [of intelligent design] in the absence of scientific proof."
  • In his in-depth examination of Design and the Many-Worlds Theory, Robin Collins explains why he thinks design is more plausible.
  • The main objections to a design of the Universe are logically analyzed in papers by Robert Koons (Do anthropic coincidences require an explanation?) and William Lane Craig (The Teleological Argument and The Anthropic Principle).
  • Hugh Ross examines Design and the Anthropic Principle
  • Cardinal Schönborn [very little of his article was on multiverse, so skip it?] - plus his views on biological evolution. {4 k}
    responses from atheists:
  • Theodore Drange examines The Fine-Tuning Argument and argues against design.
  • Victor Stenger describes inflationary many-universe cosmology and argues for non-design by asking, Does the Cosmos Show Evidence of Purpose?

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