Monday, August 4, 2014

God's Gift to Man--the Transforming Power of Music.

"Music has power to soothe the savage breast." William Congreve, The Mourning Bride
 "This so-called ‘music,’ they would have to concede, is in some way efficacious to humans. Yet it has no concepts, and makes no propositions; it lacks images, symbols, the stuff of language. It has no power of representation. It has no relation to the world."  Oliver Sacks, The Power of Music *
"Sing unto the LORD with the harp; with the harp, and the voice of a psalm.  With trumpets and sound of cornet make a joyful noise before the LORD, the King." Psalm 98:5,6 (KJV)
"Did you write the book of love,And do you have faith in God above,If the Bible tells you so?Do you believe in rock n'roll,Can music save your mortal soul?Don McLean, American Pie 
This post is a reflection on how music has shaped my devotion to the Church.     There will be links to my favorite music:  liturgical, hymns and other.   I'd be grateful if readers would note in comments their favorite music.   I won't say much about the psychology of music or how music affects the brain.   A lot of work has been done in functional imaging, but I'm not sure we know much more now than when Pythagoras noted the beautiful mathematical relations between harmonious intervals.    However, for those interested in pursuing the subject, I will give references**.

My first encounter with the power of music in liturgy came at a 40 Hours devotional service. (See Top Down to Jesus) .     I had been preparing for entry into the Church and although on rational grounds I had come to believe in the Resurrection and its implications, there were matters of dogma I found  difficult to understand, particularly that important one, transubstantiation, the change of the substance of the host into the body of Christ.   As the monstrance was carried in during the procession of the 40 Hours service,  Tantum Ergo was played, and I read in the missal
"Præstet fides supplementum, Sensuum defectui."
enough of my high school Latin came back, "faith will supplement the deficiency of the senses", and I realized in my heart, that the wafer, the host, was the body of Christ, that it was mystery beyond science and philosophy, and my eyes filled with tears.

Other liturgical music has struck to my heart in ways no homily or theological text seems to do.    During my first Easter Vigil Mass  The Litany of the Saints was played, and an overwhelming  vision of the history of the Church and all its holy people came to me.    During  Vespers at St. Vincent Archabbey (attended during retreat as Benedictine Oblate) or Evensong services at  the St. Thomas More Anglican Usage Parish,  a great peace and understanding  comes over me as I listen to the strong voices chanting the psalms. 

Other music, not  liturgical--Bach (the B minor Mass,  Jesu Joy of Man's Desiring), Mozart's Requiem, Ralph Vaughan William's Dona Nobis Pacem,  will bring me to thoughts of God.  Hymns  that I want to be played at my funeral have made their mark:  Amazing Grace, Shall We Gather by the River,  Jerusalem my Happy Home, The Lord of the Dance (old and corny pieces from evangelical churches, for the most part).   And there are those I play with the instrumental group at Church, It is Well with my Soul, Panis Angelicus, Mozart's Ave VerumThe King of Love My Shepherd Is. Old 100th and so many others.  (I play the alto clarinet, not well, but enough to provide harmony--a bass voice, since I can't sing on key.***)

One thing should be clear: it isn't the music by itself that is moving, but the total situation:  liturgy, congregation, and the words.   I could read
"Amazing Grace, how sweet the sound,That saved a wretch like me.I once was lost but now am found,Was blind, but now I see.T'was Grace that taught my heart to fear.And Grace, my fears relieved.How precious did that Grace appearThe hour I first believed." Liberty Lyrics John Newton 
It would be moving, but it is the combination of the words that reflect my own experience AND the music that brings me to tears of joy.  I could read the verses of Tantum Ergo and Pange Lingua, but it would not be meaningful without the presence of Christ's body, the procession, the Benediction,  and the congregation sharing this experience.

Am I only being sentimental and not truly devoted to the austere beauty of liturgy in my reaction to this music--too catholic (with a lower-case c)?   Some Church liturgists might think so.
"It is not surprising that Church leaders have doubted whether the feelings which music arouses are truly religious.  Music's power to fan the flames of piety may be more apparent than real..."Anthony Storr, Music and the Mind     
The Hebrews did not worry about music being a distraction from devotion to the Lord.    David danced in the procession to the altar and the psalms say "Sing to the Lord a new song,  play the lute, the lyre and the harp, sound the trumpets".    St. Augustine, entranced by music, was concerned that this power might enable the senses to overcome the intellect in worship:
"So I waver between the danger that lies in gratifying the senses and the benefits which, as I know, can accrue from singing....I am inclined to approve of the custom of singing in church, in order that by indulging the ears weaker spirits may be inspired  with feelings of devotion.  Yet when I find the singing itself more moving than the truth  which it conveys, I confess it is a grievous sin, and at those times I would prefer not to hear the singer. (emphasis added)" St. Augustine, Confessions
The last sentence in the quote is the foundation for the expulsion of music from the Church in Calvinist sects (read "The Warden" by Anthony Trollope).   I cannot subscribe to that view.  I am one of St. Augustine's weaker spirits.   I believe God gave many many gifts to man in giving him intelligence:  language, mathematics, music, art.   Music has the power to heal the soul (as Oliver Sacks shows in Musicophilia) and to bring one closer to God.   We give joy to God  when we rejoice in music, not only to praise Him, but to rejoice in life (l'Chaim)


*This quote, to show what a strange gift  music is, comes from Arthur C. Clarke's classic "Childhood's End", in which an alien species comes to guide mankind from childhood to maturity.   The very intelligent aliens do not understand the power of music.    They go to a concert,  listen politely and come away wondering.

**REFERENCES.

Robert Jourdain, Music, the Brain and Ecstasy: How Music Captures Our Imagination. 
Oliver Sacks, Musicophilia, Tales of Music and the Brain
Anthony Storr, Music and the Mind

***A MUSICAL AUTOBIOGRAPHY

I am musical but untalented (unlike my younger and older brothers).   At the age of 8, I didn't pass an audition at our Temple Youth Choir because I couldn't carry a tune.  So, I took up the clarinet as a biddable instrument-- if you put your fingers on the right keys, the right note comes out (given a certain amount of play in lipping the reed).     However, the biddability of the clarinet and my own talent weren't sufficient to let me do well in junior high school band, so that clarinet was put away until after my retirement, when I took up playing again: bass clarinet, then alto clarinet and the bowed psaltery.  Throughout my life from a teenager on, I have enjoyed classical music, folk music and some of the Golden Oldies--no rap, no hard rock, none of the stuff that's played on most radio stations.

My musical tastes are catholic (lower-case c).   On my Pandora web site are listed stations including Callas, Pavarotti, Fleming,  St. Martin's in the Fields, Gilbert & Sullivan, Bach, Mozart, klezmer, Sephardic, Ashokan Farewell, bluegrass.   Such music is moving in different ways--Ravel's  Bolero, the Wedding Scene from Fiddler on the Roof, The Beatles' "Let it Be", the final scene from Der Rosenkavalier, American Pie...(added later) Ode to Joy (Beethoven's 9th)

Wednesday, July 16, 2014

Philosophic Issues in Cosmology 8: Foundational Propositions and Conclusions

One question in science is not  ' is this hypothetical model true' but "is this model better than the alternatives'...If we believe dogmatically in a particular view, then no amount of contradictory data will convince us otherwise...” John Skilling, “Foundations and Algorithms” in Bayesian Methods in Cosmology
This is the eighth post summarizing Issues in the Philosophy of Cosmology by George F.R.  Ellis.   A complete list of the issues and theses he presents is given in the Appendix below*.    Before addressing the philosophic issues themselves, some preliminary remarks are in order.
  •  First, because of space limitations, the summary has been selective; a number of technical issues have not been discussed; if a reader is interested in these, I'd recommend the original article, via the web link given above. 
  • Second, contrary to some comments on these posts, neither Ellis nor I are making any arguments for theism or anti-atheism in the post proper; philosophic alternatives are presented, and if a reader draws theological conclusion from these alternatives, that's up to him/her. 
  • Third, no values for evidential probability (in the post on Anthropic Coincidences) have been presented; indeed, Ellis argues (and I agree) that inferring an evidential probability for one datum (our universe) is not a valid procedure. 
  • Fourth, the general focus of the article, and my emphasis in these posts, is on what can science say about cosmology and what philosophic assumptions underlie such scientific conclusions.

SCIENTIFIC CRITERIA

Ellis gives as an important criteria for a scientific theory that it be empirically testable.  My position may be even stronger than that of Ellis: if a theory cannot be confirmed by quantitative measurements then it is not in my view (and that of Fr. Stanley Jaki), science, but something else—mathematical metaphysics?

  • What can be confirmed by measurement is limited by the time, distance and physics horizons mentioned in the first post. 
  • Using electromagnetic radiation we cannot see further back in time than when radiation decoupled from matter, about 380,000 years after the origin. 
  • We cannot see further in space than given by the distance horizon, the distance at which space will be expanding at faster than the speed of light. 
  • We cannot duplicate the tremendous energies present in the initial, quantum stages of the beginning of the universe (these energies are orders of magnitude greater than even the huge energies that will be available in the SLAC Hadron supper collider), so we cannot test projected theories of particle creation. 

What can be measured are inferred consequences of various theories: what the cosmic background radiation (CBR) shows about homogeneity, isotropy, fluctuations, the cosmological constant (lambda, representing expansion pressure), etc. Recent examples are the report of Gurzadyan and Penrose of rings in the CBR representing cataclysmic events pre-Big Bang  and B-mode measurements  of the CBR from which are inferred gravitational waves in the early universe and thus inflation.   One may disagree with the aspects of the theory, but the tie-in with measured data is commendable.

THESES FOR PHILOSOPHIC ISSUES 

Ellis gives a series of theses for his position on philosophic issues and these are presented as an appendix, to give a complete summary. The theses in Issue F, “The explicit philosophic basis”, will be presented in detail. As a preliminary and review, here are theses pertinent to the science of cosmology (NOTE: the theses are taken directly from the article even though no quotation marks are present):
  • THESIS A1: The universe itself cannot be subjected to physical experimentation. We cannot re-run the universe with the same or altered conditions to see what would happen if they were different , so we cannot carry out scientific experiments on the universe itself.
  • THESIS A2: The universe cannot be observationally compared with other universes.  We cannot compare the universe with any similar object, nor can we test our hypotheses about it by observations determining statistical properties of a known class of physically existing universes.
  • THESIS B3: Establishing a Robertson-Walker geometry for the universe relies on plausible philosophic assumptions. The deduction of spatial homogeneity follows not directly from astronomical data but because we add to the observations a philosophical principle that is plausible but untestable.

(In Thesis B3, Ellis refers to the notion that the universe is isotropic and homogeneous (on a large scale). From our vantage point, we can see that the CBR (cosmic background radiation) yields this result; but to show that the inference is valid for the universe as a whole, we would need to make the same observation from at least two other (far removed) vantage points. However, if the Copernican Principle is invoked that we do not occupy a special place in the universe (this is the philosophic principle Ellis refers to in Thesis B3), then what see is equivalent to what would be seen from other positions, and the homogeneity and isotropy is demonstrated.)
  • THESIS B6: Observational horizons limit our ability to observationally determine the very large scale geometry of the universe.  We can only see back to the time of decoupling of matter and radiation and so have no direct information about earlier times; and unless we live in a 'small universe', most of the matter in the universe is hidden behind the visual horizon. Conjectures as to its geometry on larger scales cannot be observationally tested. The situation is completely different in the small universe case: then we can see everything there is in the universe, including our own galaxy at earlier times! (emphasis and exclamation point added)
  • THESIS C1: The Physics Horizon limits our knowledge of physics relevant to the very early universe. We cannot experimentally test much of the physics that is important in the very early universe because we cannot attain the required energies in accelerators on Earth. We have to extrapolate from known physics to the unknown and then test the implications; to do this, we assume some specific features of known lower energy physics are the true key to how things are at higher energies. We cannot experimentally test if we have got it right. 
  • THESIS C2: The unknown nature of the inflation means inflationary universe proposals are incomplete. The promise of inflationary theory in terms of relating cosmology to particle physics has not been realized. This will only be the case when the nature of the inflaton (the particle representing the scalar force causing inflation)has been pinned down to a specific field that experiment confirms or particle physics requires to exist.
  • THESIS D2: Testable physics cannot explain the initial state and hence specific nature of the universe. (emphasis added)
Ellis expands on Thesis D2 as follows:
    "A choice between different contingent possibilities has somehow occurred; the fundamental issue is what underlies this choice. Why does the universe have one specific form rather than another, when other forms consistent with physical laws seem perfectly possible? The reason underlying the choice between different contingent possibilities for the universe (why one occurred rather than another) cannot be explained scientifically. It is an issue to be examined through philosophy or metaphysics." (emphasis added).
This last proposition is, I believe, the most important of those Ellis sets forth.
  • THESIS E1: Physical laws may depend on the nature of the universe.
Ellis is saying here that the fundamental constants (e.g. the fine-structure constant, the gravitational constant may vary in time and space). It is a philosophical assumption that they remain constant. (Note: one recent finding, which is controversial, suggests that there is an asymmetric variation through space [and time] in the fine-structure constant.)


PHILOSOPHIC CRITERIA FOR SCIENTIFIC THEORIES

  • THESIS F1: Philosophic choices necessarily underlie cosmological theory.Unavoidable metaphysical issues inevitably arise, in both observational and physical cosmology. Philosophical choices are needed in order to shape the theory.
  •  THESIS F2: Criteria of satisfactoriness for theories cannot be scientifically chosen or validated. Criteria of satisfactoriness are necessary for choosing good cosmological theories; these criteria have to be chosen on the basis of philosophical considerations. They should include criteria for satisfactory structure of the theory, intrinsic explanatory power, and observational and experimental support.   These criteria are listed below:

1. Satisfactory structure:  a) internal consistency, b) simplicity (Ockham's razor), and c) aesthetic appeal ('beauty' or 'elegance')
    2. Intrinsic explanatory power: a) logical tightness, b) scope of the theory—the ability to unify otherwise separate phenomena, and c) probability of the theory or model with respect to some well-defined measure.
      3. Extrinsic explanatory power, or relatedness: a) connectedness to the rest of science, b) extendability providing a basis for further development;
        4. Observational and experimental support, in terms of a) testability: the ability to make quantitative as well as qualitative predictions that can be tested; and b) confirmation: the extent to which the theory is supported by such tests as have been made.” (emphasis added)
          The last criterion in my view (and that of many other scientists and philosophers of science) is critical. If a theory cannot in principle be confirmed quantitatively it is not science, but belongs to other disciplines.
          • THESIS F3: Conflicts will inevitably arise in applying criteria for satisfactory cosmological theories. Philosophical criteria for satisfactory cosmological theories will in general come into conflict with each other, so that one will have to choose between them to some degree; this choice will shape the resulting theory.
          Ellis elaborates on this last thesis:
          “The thrust of much recent development has been away from observational tests towards strongly theoretical based proposals, indeed sometimes almost discounting observational tests. (emphasis added) At present this is being corrected by a healthy move to detailed observational analysis of the proposed theories, marking a maturity of the subject.”
          • THESIS F4: The physical reason for believing in inflation is its explanatory power as regards structure growth in the universe. ... This theory has been vindicated spectacularly through observations of the CBR and matter power spectra. It is this explanatory power that makes it so acceptable to physicists, even though the underlying physics is neither well-defined nor tested, and its major large-scale observational predictions are untestable. (emphasis added).
          Expanding on Thesis F4, Ellis adds:
          “Inflation provides a causal model that brings a wider range of phenomena into what can be explained by cosmology (Criterion 2b), rather than just assuming the initial data had a specific restricted form. Explaining flatness (omega0 approximately 1, as predicted by inflation) and homogeneity reinforces the case, even though these are philosophical rather than physical problems (they [the initial restricted conditions] do not contradict any physical law; things could just have been that way). However claims on the basis of this model as to what happens very far outside the visual horizon (as in the chaotic inflationary theory) results from prioritizing theory over the possibility of observational and experimental testing. It will never be possible to prove these claims are correct.” (emphasis added)
          Ellis asks, “how much should we try to explain” with cosmology? What should the scope of cosmology include?

          • THESIS F5:Cosmological theory can have a wide or narrow scope of enquiry. The scope we envisage for our cosmological theory shapes the questions we seek to answer. The cosmological philosophical base becomes more or less dominant in shaping our theory according to the degree that we pursue a theory with more or less ambitious explanatory aims in terms of all of physics, geometry and underlying fundamental causation.

          Elaborating on this point, Ellis says
          “...The study of expansion of the universe and structure formation from nucleosynthesis to the present day is essential and well-informed. The philosophical stance adapted is minimal and highly plausible. The understanding of physical processes at earlier times, back to quantum gravity, is less well-founded. The philosophical stance is more significant and more debatable. Developments in the quantum gravity era are highly speculative, the philosophical position adapted is dominant because experimental and observational limits on the theory are lacking.” (emphasis added)....the basic underlying cosmological questions are
          1. Why do the laws of physics have the form they do? Issues arise such as what makes particular laws work? for example, what governs the behaviour of a proton, the pull of gravity?...
          2. Why do boundary conditions have the form they do?
          3. Why do laws of physics at all exist? This relates to unsolved issues concerning the nature of the laws of physics: are they descriptive or prescriptive? ...Is the nature of matter really mathematically based in some sense, or does it just happen that its behaviour can be described in a mathematical way?
          4. Why does anything exist? This profound existential question is a mystery whatever approach we take.
          5. Why does the universe allow the existence of intelligent life? This of somewhat different character than the others and largely rests on them but is important enough to generate considerable debate in its own right. (Note: this question is that related to the Anthropic Principle--#6 in this series.)
           The status of all these questions is philosophical rather than scientific, for they cannot be resolved purely scientifically. How many of them—if any—should we consider in our construction of and assessments of cosmological theories?”
          The next important question Ellis considers is how well does science, particularly cosmology, represent reality.
          “It follows...that there are limits to what the scientific method can achieve in explanatory terms. We need to respect these limits and acknowledge clearly when arguments and conclusions are based on some philosophical stance rather than on purely testable scientific argument. If we acknowledge this and make that stance explicit , then the bases for different viewpoints are clear and alternatives can be argued rationally.”

          • THESIS F6: Reality is not fully reflected in either observations or theoretical models. Problems arise from confusion of epistemology (the theory of knowledge) with ontology (the nature of existence) existence is not always manifest clearly in the available evidence. The theories and models of reality we use as our basis for understanding are necessarily partial and incomplete reflections of the true nature of reality, helpful in many ways but also inevitably misleading in others. They should not be confused with reality itself!”

          “It may be suggested that arguments ignoring the need for experimental/observational verification of theories ultimately arise because these theories are being confused with reality, or at least are being taken as completely reliable total representation of reality. (emphasis added)   This occurs in
          • "... confusing computer simulations of reality with reality itself, when they can in fact represent only a highly simplified and stylized version of what actually is."
          • "...confusing the laws of physics themselves with their abstract mathematical representation (if indeed they [the laws] are ontologically real)
          • ... confusing a construction of the human mind (“Laws of Physics”) with the reliable behaviour of ponderable matter...
          • ...confusing theoretically based outcomes of models with proven observational results (e.g. claiming the universe necessarily has flat special sections (omega0 =1) and so this can be taken for granted, when the value of omega0 can and should be observationally determined precisely because this then tests that prediction.)”
          Another  important question Ellis addresses is whether infinities are physically realizable or mathematical constructs. He agrees with the renowned 20th century mathematician David Hilbert that infinity is not a real quantity:
          “Our principal result is that the infinite is nowhere to be found in reality. It neither exists in nature nor provides a legitimate basis for rational thought . . . The role that remains for the infinite to play is solely that of an idea .. . which transcends all experience and which completes the concrete as a totality . . .” (quote is from Hilbert).
          Since one can never count an infinite number of objects, the claim that the universe is infinite or that there are an infinite number of universes in a multiverse can never be tested or confirmed.

          • THESIS I2: The often claimed physical existence of infinities is questionable. The claimed existence of physically realized infinities in cosmology or multiverses raises problematic issues. One can suggest they are unphysical; in any case such claims are certainly unverifiable.

          Ellis concludes that there is much uncertainty in what one can infer from cosmology, and those inferences one draws are based on the philosophical basis one uses. More importantly, the stance one takes should be related to the totality of man's existence in the universe.
          “Firstly, even in order to understand just the material world, it can be claimed that one needs to consider forms of existence other than the material only — for example a Platonic world of mathematics and a mental world, both of which can be claimed to exist and be causally effective in terms of affecting the material world. Our understanding of local causation will be incomplete unless we take them into account.
           Secondly, in examining these issues one needs to take into account data about the natures of our existence that come from our daily lives and the broad historical experience of humanity (our experiences of ethics and aesthetics, for example), as well as those discoveries attained by the scientific method. Many writings claim there is no purpose in the universe: it is all just a conglomerate of particles proceeding at a fundamental level in a purposeless and meaningless algorithmic way. But I would reply, the very fact that those writers engage in such discourse undermines their own contention; they ignore the evidence provided by their own actions. There is certainly meaning in the universe to this degree: the fact they take the trouble to write such contentions is proof that they consider it meaningful to argue about such issues; and this quality of existence has emerged out of the nature of the physical universe.... Indeed the human mind is causally effective in the real physical world precisely through many activities motivated by meanings perceived by the human mind. Any attempt to relate physics and cosmology to ultimate issues must take such real world experience seriously, otherwise it will simply be ignoring a large body of undeniable data. This data does not resolve the ultimate issues, but does indicate dimensions of existence that indeed do occur.”
          With respect to the significance of cosmology, Ellis concludes

          • THESIS OF UNCERTAINTY: Ultimate uncertainty is a key aspect of cosmology.Scientific exploration can tell us much about the universe, but not about its ultimate nature, or even much about some if its major geometrical and physical characteristics. Some of this uncertainty may be resolved, but much will remain. Cosmological theory should acknowledge this uncertainty.

          Some final thoughts of my own:

          • First, Ellis's review of the philosophical issues underlying cosmology is a most useful antidote to more grandiose presentations that ignore considerations of epistemology and metaphysics. Although in this article he touches only lightly on the place of man in the cosmos, he has also written a short book, “Before the Beginning-Cosmology Explained”, that addresses this question and theological considerations more fully. The book also gives a much simpler (ground up from basic physics) summary of the science in cosmology than that in the article.
          • Second, much of the reasoning used to justify various cosmological models and theories is abductive , that is, to say that theory/model is "true" because it is the best (most elegant) explanation for the phenomena.   That type of reasoning has been criticized by philosophers of science, e.g. Bas van Fraassen, William Stoeger, Nancy Cartwright.    There are historical examples to show that the best explanation (at the time) is not necessarily true--e.g. phlogiston, disproved by Count Rumford's cannon-boring experiments, the ether, disproved by the Michelson-Morley experiments.     Unfortunately (or maybe fortunately), as Ellis emphasizes, we can't experiment on the cosmos.


          APPENDIX

          SUMMARY TABLE OF ISSUES AND THESES
          Issue A: The uniqueness of the universe

          • Thesis A1: The universe itself cannot be subjected to physical experimentation
          • Thesis A2: The universe cannot be observationally compared with other universes
          • Thesis A3: The concept of ‘Laws of Physics’ that apply to only one object is questionable
          • Thesis A4: The concept of probability is problematic in the context of existence of only one object

          Issue B: The large scale of the Universe in space and time

          • Thesis B1: Astronomical observations are confined to the past null cone, and fade with distance
          • Thesis B2: ‘Geological’ type observations can probe the region near our past world line in the very distant past
          • Thesis B3: Establishing a Robertson-Walker geometry relies on plausible philosophical assumptions
          • Thesis B4: Interpreting cosmological observations depends on astrophysical understanding
          • Thesis B5: A key test for cosmology is that the age of the universe must be greater than the ages of stars
          • Thesis B6: Horizons limit our ability to observationally determine the very large scale geometry of the universe
          • Thesis B7: We have made great progress towards observational completeness

          Issue C: The unbound energies in the early universe

          • Thesis C1: The Physics Horizon limits our knowledge of physics relevant to the very early universe
          • Thesis C2: The unknown nature of the inflaton means inflationary universe proposals are incomplete

          Issue D: Explaining the universe — the question of origins

          • Thesis D1: An initial singularity may or may not have occurred
          • Thesis D2: Testable physics cannot explain the initial state and hence specific nature of the universe
          • Thesis D3: The initial state of the universe may have been special or general

          Issue E: The Universe as the background for existence

          • Thesis E1: Physical laws may depend on the nature of the universe
          • Thesis E2: We cannot take the nature of the laws of physics for granted
          • Thesis E3: Physical novelty emerges in the expanding universe

          Issue F: The explicit philosophical basis

          • Thesis F1: Philosophical choices necessarily underly cosmological theory
          • Thesis F2: Criteria for choice between theories cannot be scientifically chosen or validated
          • Thesis F3: Conflicts will inevitably arise in applying criteria for satisfactory theories
          • Thesis F4: The physical reason for believing in inflation is its explanatory power re structure growth.
          • Thesis F5: Cosmological theory can have a wide or narrow scope of enquiry
          • Thesis F6: Reality is not fully reflected in either observations or theoretical models

          Issue G: The Anthropic question: fine tuning for life

          • Thesis G1: Life is possible because both the laws of physics and initial conditions have a very special nature
          • Thesis G2: Metaphysical uncertainty remains about ultimate causation in cosmology

          Issue H: The possible existence of multiverses

          • Thesis H1: The Multiverse proposal is unprovable by observation or experiment
          • Thesis H2: Probability-based arguments cannot demonstrate the existence of multiverses
          • Thesis H3: Multiverses are a philosophical rather than scientific proposal
          • Thesis H4: The underlying physics paradigm of cosmology could be extended to include biological insights

          Issue I: The natures of existence
          Thesis I1: We do not understand the dominant dynamical matter components of the universe at early or late times
          Thesis I2: The often claimed physical existence of infinities is questionable
          Thesis I3: A deep issue underlying the nature of cosmology is the nature of the laws of physics.
          Thesis of Uncertainty: Ultimate uncertainty is one of the key aspects of cosmology


          Tuesday, July 15, 2014

          Philosophic Issues in Cosmology 7: Is there a Multiverse?

          Exploding Universes in a Multiverse Section
          from Andrei Linde, Stanford University
          “It’s hard to build models of inflation that don't lead to a multiverse. It’s not impossible, so I think there’s still certainly research that needs to be done. But most models of inflation do lead to a multiverse, and evidence for inflation will be pushing us in the direction of taking [the idea of a] multiverse seriously.” Alan Guth
           "Well, there is the hypothesis ... that all possible universes exist, and we find ourselves, not surprisingly, in one that contains life. But that is a cop-out, which dispenses with the attempt to explain anything. And without the hypothesis of multiple universes, the observation that if life hadn't come into existence we wouldn't be here has no significance. One doesn't show that something doesn't require explanation by pointing out that it is a condition of one's existence. If I ask for an explanation of the fact that the air pressure in the transcontinental jet is close to that at sea level, it is no answer to point out that if it weren't, I'd be dead.” Thomas Nagel, Mind and Cosmos.
          This is the seventh in a series of posts summarizing Issues in the Philosophy of Cosmology  by George F.R. Ellis*.   Also, we'll discuss "inflation" below**, the extremely rapid expansion of the very early universe, since the existence of "bubble universes", a multiverse is predicated on inflation, and since this was not discussed extensively in previous posts.

          The notion of an ensemble of many possible universes (small u), not causally connected, “a multiverse”, has been used to counter the unlikeliness of all the anthropic coincidences.  To quote Ellis*:
          If there is a large enough ensemble of numerous universes with varying properties, it may be claimed that it becomes virtually certain that some of them will just happen to get things right, so that life can exist;  and this can help explain the fine-tuned nature of many parameters whose value values are otherwise unconstrained by physics... However there are a number of problems with this concept.  Besides, this proposal is observationally and experimentally untestable, thus its scientific status is debatable.” (emphasis added).

          One  problem (other than the untestable aspect) is that the probabilistic character of the multiverse is never specified by authors who invoke it: 
          “These three elements (the possibility space [the population description], the measure [the quantities  that describe the particular universe], and the distribution function [for the measure]) ,must all be clearly defined in order to give a proper specification of a multiverse.... This is almost never done.”

          What is also not usually specified are the possible types of universes contained in a multiverse.  Which of the types below should be included?
          • “Weak Variation: only the values of the constants of physics are allowed to vary?...
          • Moderate Variation: different symmetry groups, or numbers of dimensions...
          • Strong Variation: different numbers and kinds of forces, universes without quantum theory or in which relativity is untrue (e.g. there is an aether), some in which string theory is a good theory for quantum gravity and others where it is not, some with quite different bases for the laws of physics (e.g. no variational principles).
          • Extreme Variation:  universes where physics is not well described by mathematics, with different logic; universes ruled by local deities; allowing magic... Without even mathematics or logic?
           Which is claimed to be the properties of the multiverse, and why?  We can express our dilemma here through the paradoxical question: Are the laws of logic necessary in all possible universes?”

          Although the existence of multiverses cannot be justified by measurements, do they offer good explanations for the anthropic coincidences?  Ellis answers:
          It has been suggested that they (multiverses)  explain the parameters of physics and of cosmology and in particular the very problematic values of the cosmological constant (lambda, the constant for negative pressure)  The argument goes as follows:  assume a multiverse exists;  observers can only exist in one of the highly improbable biophilic outliers where the value of the cosmological constant is very small. ...If the multiverse has many varied locations with differing properties that may indeed help us understand the Anthropic issue:  some regions will allow life to exist, others will not.   This does provide a useful modicum of explanatory power.  However it is far from conclusive(emphasis added
          Firstly, it is unclear why the multiverse should have the restricted kinds of variations of the cosmological constant assumed in (these) analyses...If we assume 'all that can happen, happens' the variations will not be of that restricted kind;  those analyses will not apply.”
          Secondly, ultimate issues remain.  Why does the unique larger whole (the multiverse)have the properties it does? (emphasis added)  Why this multiverse rather than any other one?”

          I will add to Ellis's comment that even though one universe in a multiverse has  an appropriate value for a particular constant (say, lambda), it will not necessarily be the case that other parameters will be appropriate.    There still has to be a conjunction of values for all the laws and constants, which requires either a Theory of Everything to give that (something to wonder about in itself) , or more amazing coincidences.

          Ellis further argues that probability-based arguments cannot demonstrate the existence of a multiverse:
          “Probability arguments cannot be used to prove the existence of a multiverse, for they are only applicable if a multiverse (that is to say, a population of multiverses) exists.   Furthermore probability arguments can never prove anything for certain, as it is not possible to violate any probability predictions, and this is a fortiori so when there is only one case to consider, so that no statistical observations  are possible. (emphasis in the original).  All one can say on the basis of probability arguments is that some specific state is very improbable.  But this does not prove it is impossible;  indeed if is stated to have a low probability, that is precisely a statement that it is possible... probability arguments ...(are) equivalent to the claim that the universe is generic rather than special, but whether this is so or not is precisely the issue under debate.”

          The issue of whether a multiverse can contain an infinite number of universes (thus justifying the claim that “whatever can happen will happen”) is addressed by Ellis as part of the question whether an infinite number can be considered as real (rather than as a mathematical construct) in his analysis of the philosophic/ metaphysical questions involved in cosmology, and will be discussed in the last post of this summary.

          In conclusion, Ellis argues  that Multiverses are a philosophical rather than scientific proposal. 
          “The idea of a multiverse provides a possible route for the explanation of fine-tuning.  But it is not uniquely defined, is not scientifically testable ... and in the end simply postpones the ultimate metaphysical questions.”

          These philosophic issues will be discussed in the final post of this series. 

          *Quotations, unless otherwise specified, are from Issues in the Philosophy of Cosmology , George F.R. Ellis.


          **All about Inflation.

          One development of quantum cosmology that does have measurable consequences is the notion of inflation introduced by Guth (1981), here explained by Ellis:
          Particle physics processes dominated the very early eras, when exotic processes took place such as the condensation of a quark-gluon plasma to produce baryons. Quantum field theory effects were significant then, and this leads to an important possibility: scalar fields producing repulsive gravitational effects could have dominated the dynamics of the universe at those times. This leads to the theory of the inflationary universe, proposed by Alan Guth ...an extremely short period of accelerating expansion will precede the hot big bang era . This produces a very cold and smooth vacuum-dominated state, and ends in ‘reheating’: conversion of the scalar field to radiation, initiating the hot big bang epoch. This inflationary process is claimed to explain the puzzles mentioned above: why the universe is so special (with spatially homogeneous and isotropic geometry and a very uniform distribution of matter), and also why the space sections are so close to being flat at present (we still do not know the sign of the spatial curvature), which requires very fine tuning of initial conditions at very early times.   (emphasis added) Inflationary expansion explains these features because particle horizons in inflationary FL models will be much larger than in the standard models with ordinary matter, allowing causal connection of matter on scales larger than the visual horizon, and inflation also will sweep topological defects outside the visible domain.”
          Inflation also explains the rarity (absence) of magnetic monopoles (predicted by the standard model of particle physics), the presence of stars/galaxies (from quantum fluctuations expanded by inflation) and several features of the observed CBR (Cosmic Background Radiation).    The projected time scale for the inflationary period is from about 10^-36s after the origin to about 10^-32s, during which period the volume increased by a factor of at least 10^78.   As pointed out above, the source of the inflationary increase is an assumed force, a scalar field or isotropic negative pressure, counteracting the force of gravity. Although the notion of inflation explains many puzzling features about our universe, not all physicists are satisfied with this explanation.   Other explanations have been offered, and as Ellis says:
          “The promise of inflationary theory in terms of relating cosmology to particle physics has not been realized. This will only be the case when the nature of the inflaton (the hypothetical particle corresponding to the scalar inflationary field).  has been pinned down to a specific field that experiment confirms or particle physics requires to exist.outside the visible domain.” (emphasis in the original).
           Roger Penrose also has misgivings about inflationary theory, primarily due to what he thinks is a misplaced motivation for applying the theory to explain flatness and homogeneity:
          “In the standard model these issues (the flatness, horizon and smoothness problems) are handled by the 'fine-tuning' of the initial Big Bang state, and this is regarded by inflationists as “ugly”.   The claim is that the need for such fine tuning is removed in the inflationary picture and this is regarded as a more aesthetically pleasing physical  picture.”  (Road to Reality, p.754)
           It should be understood that in this context, “aesthetically pleasing” corresponds to the absence of an intelligent designer to set the “fine-tuning”,  that is to say the absence of a creative God, or, alternatively, the absence of an as yet unknown “theory of everything” that would set the fine-tuning by some universal physical law (my take).

          Recent B-mode measurements of the microwave background radiation are in agreement with inflation in that there is evidence of strong gravitational waves in the radiation.

          Taking inflation to be true because it is the "best" explanation for several cosmological features is an example of "abductive" reasoning, reasoning to the best explanation.    Such reasoning has been faulted by several  philosophers of science (Nancy Cartwright, Bas van Fraassen) with some cause.   Historically phlogiston was the best explanation for heat before Count Rumford's cannon-boring experiments;  ether was the best explanation for electromagnetic wave vibration before the Michelson-Morley experiments.

          About Me

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          Retired, cranky, old physicist.   Convert to Catholicism in 1995.   Trying to show that there is no contradiction between what science tells us about the world and our Catholic faith.   Intermittent blogs and adult education classes to achieve this end (see http://rationalcatholic.blogspot.com/   and http://home.ptd.net/~rkurland)

          Extraordinary Minister of Communion volunteer to federal prison and hospital; lector, EOMC.
          Sometime player of bass clarinet, alto clarinet, clarinet, bass, tenor bowed psaltery for parish instrumental group and local folk group.

          And, finally, my motivation:
          “It is also necessary—may God grant it!—that in providing others with books to read I myself should make progress, and that in trying to answer their questions I myself should find what I am seeking.
          Therefore at the command of God our Lord and with his help, I have undertaken not so much to discourse with authority on matters known to me as to know them better by discoursing devoutly of them.”
          St. Augustine of Hippo, The Trinity I,8.