From: Keith B Miller (
Date: Wed Apr 04 2001 - 22:45:29 EDT

  • Next message: Keith B Miller: "ID.Weinberg 2"

    This essay by Weinberg might be a good focus for dissecting the arguments
    of a philosophical materialist.


    >A Designer Universe?
    >(Nobelist in physics)
    >I have been asked to comment on whether the universe shows signs of having
    >been designed.[1] I don't see how it's possible to talk about this without
    >having at least some vague idea of what a designer would be like. Any
    >possible universe could be explained as the work of some sort of designer.
    >Even a universe that is completely chaotic, without any laws or
    >regularities at all, could be supposed to have been designed by an idiot.
    >The question that seems to me to be worth answering, and perhaps not
    >impossible to answer, is whether the universe shows signs of having been
    >designed by a deity more or less like those of traditional monotheistic
    >religionsónot necessarily a figure from the ceiling of the Sistine Chapel,
    >but at least some sort of personality, some intelligence, who created the
    >universe and has some special concern with life, in particular with human
    >life. I expect that this is not the idea of a designer held by many here.
    >You may tell me that you are thinking of something much more abstract, some
    >cosmic spirit of order and harmony, as Einstein did. You are certainly free
    >to think that way, but then I don't know why you use words like "designer"
    >or "God," except perhaps as a form of protective coloration.
    >It used to be obvious that the world was designed by some sort of
    >intelligence. What else could account for fire and rain and lightning and
    >earthquakes? Above all, the wonderful abilities of living things seemed to
    >point to a creator who had a special interest in life. Today we understand
    >most of these things in terms of physical forces acting under impersonal
    >laws. We don't yet know the most fundamental laws, and we can't work out
    >all the consequences of the laws we do know. The human mind remains
    >extraordinarily difficult to understand, but so is the weather. We can't
    >predict whether it will rain one month from today, but we do know the rules
    >that govern the rain, even though we can't always calculate their
    >consequences. I see nothing about the human mind any more than about the
    >weather that stands out as beyond the hope of understanding as a
    >consequence of impersonal laws acting over billions of years.
    >[1] This article is based on a talk given in April 1999 at the Conference
    >on Cosmic Design of the American Association for the Advancement of Science
    >in Washington, D.C.
    >There do not seem to be any exceptions to this natural order, any miracles.
    >I have the impression that these days most theologians are embarrassed by
    >talk of miracles, but the great monotheistic faiths are founded on miracle
    >storiesóthe burning bush, the empty tomb, an angel dictating the Koran to
    >Mohammedóand some of these faiths teach that miracles continue at the
    >present day. The evidence for all these miracles seems to me to be
    >considerably weaker than the evidence for cold fusion, and I don't believe
    >in cold fusion. Above all, today we understand that even human beings are
    >the result of natural selection acting over millions of years of breeding
    >and eating.
    >I'd guess that if we were to see the hand of the designer anywhere, it
    >would be in the fundamental principles, the final laws of nature, the book
    >of rules that govern all natural phenomena. We don't know the final laws
    >yet, but as far as we have been able to see, they are utterly impersonal
    >and quite without any special role for life. There is no life force. As
    >Richard Feynman has said, when you look at the universe and understand its
    >laws, "the theory that it is all arranged as a stage for God to watch man's
    >struggle for good and evil seems inadequate."
    >True, when quantum mechanics was new, some physicists thought that it put
    >humans back into the picture, because the principles of quantum mechanics
    >tell us how to calculate the probabilities of various results that might be
    >found by a human observer. But, starting with the work of Hugh Everett
    >forty years ago, the tendency of physicists who think deeply about these
    >things has been to reformulate quantum mechanics in an entirely objective
    >way, with observers treated just like everything else. I don't know if this
    >program has been completely successful yet, but I think it will be.
    >I have to admit that, even when physicists will have gone as far as they
    >can go, when we have a final theory, we will not have a completely
    >satisfying picture of the world, because we will still be left with the
    >question "why?" Why this theory, rather than some other theory? For
    >example, why is the world described by quantum mechanics? Quantum mechanics
    >is the one part of our present physics that is likely to survive intact in
    >any future theory, but there is nothing logically inevitable about quantum
    >mechanics; I can imagine a universe governed by Newtonian mechanics
    >instead. So there seems to be an irreducible mystery that science will not
    >But religious theories of design have the same problem. Either you mean
    >something definite by a God, a designer, or you don't. If you don't, then
    >what are we talking about? If you do mean something definite by "God" or
    >"design," if for instance you believe in a God who is jealous, or loving,
    >or intelligent, or whimsical, then you still must confront the question
    >"why?" A religion may assert that the universe is governed by that sort of
    >God, rather than some other sort of God, and it may offer evidence for this
    >belief, but it cannot explain why this should be so.
    >In this respect, it seems to me that physics is in a better position to
    >give us a partly satisfying explanation of the world than religion can ever
    >be, because although physicists won't be able to explain why the laws of
    >nature are what they are and not something completely different, at least
    >we may be able to explain why they are not slightly different. For
    >instance, no one has been able to think of a logically consistent
    >alternative to quantum mechanics that is only slightly different. Once you
    >start trying to make small changes in quantum mechanics, you get into
    >theories with negative probabilities or other logical absurdities. When you
    >combine quantum mechanics with relativity you increase its logical
    >fragility. You find that unless you arrange the theory in just the right
    >way you get nonsense, like effects preceding causes, or infinite
    >probabilities. Religious theories, on the other hand, seem to be infinitely
    >flexible, with nothing to prevent the invention of deities of any
    >conceivable sort.
    >Now, it doesn't settle the matter for me to say that we cannot see the hand
    >of a designer in what we know about the fundamental principles of science.
    >It might be that, although these principles do not refer explicitly to
    >life, much less human life, they are nevertheless craftily designed to
    >bring it about.
    >Some physicists have argued that certain constants of nature have values
    >that seem to have been mysteriously fine-tuned to just the values that
    >allow for the possibility of life, in a way that could only be explained by
    >the intervention of a designer with some special concern for life. I am not
    >impressed with these supposed instances of fine-tuning. For instance, one
    >of the most frequently quoted examples of fine-tuning has to do with a
    >property of the nucleus of the carbon atom. The matter left over from the
    >first few minutes of the universe was almost entirely hydrogen and helium,
    >with virtually none of the heavier elements like carbon, nitrogen, and
    >oxygen that seem to be necessary for life. The heavy elements that we find
    >on earth were built up hundreds of millions of years later in a first
    >generation of stars, and then spewed out into the interstellar gas out of
    >which our solar system eventually formed.
    >The first step in the sequence of nuclear reactions that created the heavy
    >elements in early stars is usually the formation of a carbon nucleus out of
    >three helium nuclei. There is a negligible chance of producing a carbon
    >nucleus in its normal state (the state of lowest energy) in collisions of
    >three helium nuclei, but it would be possible to produce appreciable
    >amounts of carbon in stars if the carbon nucleus could exist in a
    >radioactive state with an energy roughly 7 million electron volts (MeV)
    >above the energy of the normal state, matching the energy of three helium
    >nuclei, but (for reasons I'll come to presently) not more than 7.7 MeV
    >above the normal state.
    >This radioactive state of a carbon nucleus could be easily formed in stars
    >from three helium nuclei. After that, there would be no problem in
    >producing ordinary carbon; the carbon nucleus in its radioactive state
    >would spontaneously emit light and turn into carbon in its normal
    >nonradioactive state, the state found on earth. The critical point in
    >producing carbon is the existence of a radioactive state that can be
    >produced in collisions of three helium nuclei.
    >In fact, the carbon nucleus is known experimentally to have just such a
    >radioactive state, with an energy 7.65 MeV above the normal state. At first
    >sight this may seem like a pretty close call; the energy of this
    >radioactive state of carbon misses being too high to allow the formation of
    >carbon (and hence of us) by only 0.05 MeV, which is less than one percent
    >of 7.65 MeV. It may appear that the constants of nature on which the
    >properties of all nuclei depend have been carefully fine-tuned to make life
    >Looked at more closely, the fine-tuning of the constants of nature here
    >does not seem so fine. We have to consider the reason why the formation of
    >carbon in stars requires the existence of a radioactive state of carbon
    >with an energy not more than 7.7 MeV above the energy of the normal state.
    >The reason is that the carbon nuclei in this state are actually formed in a
    >two-step process: first, two helium nuclei combine to form the unstable
    >nucleus of a beryllium isotope, beryllium 8, which occasionally, before it
    >falls apart, captures another helium nucleus, forming a carbon nucleus in
    >its radioactive state, which then decays into normal carbon. The total
    >energy of the beryllium 8 nucleus and a helium nucleus at rest is 7.4 MeV
    >above the energy of the normal state of the carbon nucleus; so if the
    >energy of the radioactive state of carbon were more than 7.7 MeV it could
    >only be formed in a collision of a helium nucleus and a beryllium 8 nucleus
    >if the energy of motion of these two nuclei were at least 0.3 MeVóan energy
    >which is extremely unlikely at the temperatures found in stars.
    >Thus the crucial thing that affects the production of carbon in stars is
    >not the 7.65 MeV energy of the radioactive state of carbon above its normal
    >state, but the 0.25 MeV energy of the radioactive state, an unstable
    >composite of a beryllium 8 nucleus and a helium nucleus, above the energy
    >of those nuclei at rest. [2] This energy misses being too high for the
    >production of carbon by a fractional amount of 0.05 MeV/0.25 MeV, or 20
    >percent, which is not such a close call after all.
    >This conclusion about the lessons to be learned from carbon synthesis is
    >somewhat controversial. In any case, there is one constant whose value does
    >seem remarkably well adjusted in our favor. It is the energy density of
    >empty space, also known as the cosmological constant. It could have any
    >value, but from first principles one would guess that this constant should
    >be very large, and could be positive or negative. If large and positive,
    >the cosmological constant would act as a repulsive force that increases
    >with distance, a force that would prevent matter from clumping together in
    >the early universe, the process that was the first step in forming galaxies
    >and stars and planets and people. If large and negative the cosmological
    >constant would act as an attractive force increasing with distance, a force
    >that would almost immediately reverse the expansion of the universe and
    >cause it to recollapse, leaving no time for the evolution of life. In fact,
    >astronomical observations show that the cosmological constant is quite
    >small, very much smaller than would have been guessed from first
    >[2] This was pointed out in a 1989 paper by M. Livio, D. Hollowell, A.
    >Weiss, and J.W. Truran ("The anthropic significance of the existence of an
    >excited state of 12C," Nature, Vol. 340, No. 6231, July 27, 1989). They did
    >the calculation quoted here of the 7.7 MeV maximum energy of the
    >radioactive state of carbon, above which little carbon is formed in stars.

    Keith B. Miller
    Department of Geology
    Kansas State University
    Manhattan, KS 66506

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