This essay by Weinberg might be a good focus for dissecting the arguments
of a philosophical materialist.
Keith
>From:
>http://www.nybooks.com/nyrev/WWWarchdisplay.cgi?19991021046F
>
>A Designer Universe?
>STEVEN WEINBERG
>(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
>eliminate.
>
>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
>possible.
>
>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
>principles.
>[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
kbmill@ksu.edu
http://www-personal.ksu.edu/~kbmill/
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