[Paleopsych] CHE: Reinventing Physics: the Search for the Real Frontier

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Reinventing Physics: the Search for the Real Frontier
The Chronicle of Higher Education, 5.2.11
http://chronicle.com/weekly/v51/i23/23b00601.htm

    By ROBERT B. LAUGHLIN

    A few years ago I had occasion to engage my father-in-law, a retired
    academician, on the subject of the collective nature of physical law.
    We had just finished playing bridge late one afternoon and were
    working on a couple of gin and tonics in order to escape discussing
    movies of emotional depth with our wives. My argument was that
    reliable cause-and-effect relationships in the natural world have
    something to tell us about ourselves, in that they owe this
    reliability to principles of organization rather than microscopic
    rules. The laws of nature that we care about, in other words, emerge
    through collective self-organization and really do not require
    knowledge of their component parts to comprehend and exploit.

    After listening carefully, my father-in-law declared that he did not
    understand. He had always thought that laws cause organization, not
    the other way around. He was not even sure the reverse made sense. I
    then asked him whether legislatures and corporate boards made laws or
    were made by laws, and he immediately saw the problem. He pondered it
    for a while, and then confessed that he was now deeply confused about
    why things happen and needed to think more about it. Exactly so.

    It is a terrible thing that science has grown so distant from the rest
    of our intellectual life, for it did not start out that way. The
    writings of Aristotle, for example, despite their notorious
    inaccuracies, are beautifully clear, purposeful, and accessible. So is
    Darwin's Origin of Species. The opacity of modern science is an
    unfortunate side effect of professionalism, and something for which we
    scientists are often pilloried -- and deservedly so. Everyone gets
    wicked pleasure from snapping on the radio on the drive home from work
    to hear Doctor Science give ludicrous answers to phone-in questions
    such as why cows stand in the same direction while grazing (they must
    face Wisconsin several times a day) and then finish up with, "And
    remember: I know more than you. I have a master's degree in science."
    On another occasion my father-in-law remarked that economics had been
    terrific until they made it into a science. He had a point.

    The conversation about physical law started me thinking about what
    science had to say about the obviously very unscientific
    chicken-and-egg problem of laws, organizations of laws, and laws from
    organization. I began to appreciate that many people had strong views
    on this subject, but could not articulate why they held them. The
    matter had come to a head recently when I realized I was having the
    same conversation over and over again with colleagues about Brian
    Greene's The Elegant Universe (W.W. Norton, 1999), a popular book
    about string theory -- a set of speculative ideas about the quantum
    mechanics of space. The conversation focused on the question of
    whether physics was a logical creation of the mind or a synthesis
    built on observation.

    The impetus for the discussion was never an existential problem, of
    course, but money, the lack of which is the universal common
    denominator of world science. But the subject always seemed to drift
    back from there to the pointlessness of making models of the world
    that were beautiful but predicted no experiments, and from there to
    the question of what science is. After this happened a number of times
    in such disparate venues as Seattle, Taipei, and Helsinki, it struck
    me that the disagreement spawned by Greene's book was fundamentally
    the same problem that had occupied us that day after bridge. Moreover
    it was an ideological dispute: It had nothing to do with what was true
    and everything to do with what "true" was.

    It is commonly said in physics that good notation advances while bad
    notation retards. This is certainly true. A phonetic alphabet takes
    less time to master than a pictorial one and thus makes writing more
    accessible. Decimal numbers are easier to use than Roman numerals. The
    same idea applies to ideologies. Seeing our understanding of nature as
    a mathematical construction has fundamentally different implications
    from seeing it as an empirical synthesis. One view identifies us as
    masters of the universe; the other identifies the universe as masters
    of us. Little wonder that my colleagues down in the trenches of
    experimental science had become so animated over the question. At its
    core the matter is not scientific at all but concerns one's sense of
    self and place in the world.

    The threads of these two worlds run very deep. When I was a kid I
    drove with my parents to Yosemite for a rendezvous with my aunt and
    uncle, who had driven in from Chicago. My uncle was a brilliant and
    highly successful patent attorney who seemed to know everything and
    was not shy about sharing this fact. On this occasion he and my aunt
    checked in at the Ahwahnee, the fanciest hotel in the place, held
    court there with us, consumed a few buffet breakfasts, and then left
    to drive over Tuolumne Pass to the desert and home. I don't think they
    saw a single waterfall up close. There was no point, since they had
    seen waterfalls before and understood the concept.

    The worldview motivating my uncle's attitude toward Yosemite, and
    arguably also Brian Greene's attitude toward physics, is expressed
    with great clarity in John Horgan's The End of Science
    (Addison-Wesley, 1996), in which he argues that all fundamental things
    are now known and there is nothing left for us to do but fill in
    details. This pushes my experimental colleagues beyond their already
    strained limits of patience, for it is both wrong and completely below
    the belt. The search for new things always looks like a lost cause
    until one makes a discovery. If it were obvious what was there, one
    would not have to look for it.

    Unfortunately this view is widely held. I once had a conversation with
    the late David Schramm, the famous cosmologist at the University of
    Chicago, about galactic jets. These are thin pencils of plasma that
    beam out of some galactic cores to fabulous distances, sometimes
    several galactic radii, powered somehow by mechanical rotation of the
    core. How they can remain thin over such stupendous distances is not
    understood, and something I find tremendously interesting. But David
    dismissed the whole effect as "weather." He was interested only in the
    early universe and astrophysical observations that could shed light on
    it, even if only marginally. He categorized the jets as annoying
    distractions on the grounds that they had nothing in particular to
    tell him about what was fundamental. I, by contrast, am fascinated by
    weather and believe that people claiming not to be are fibbing.

    I think primitive organizational phenomena such as weather have
    something of lasting importance to tell us about more complex ones,
    including ourselves: Their primitiveness enables us to demonstrate
    with certainty that they are ruled by microscopic laws but also,
    paradoxically, that some of their more sophisticated aspects are
    insensitive to details of these laws. In other words, we are able to
    prove in these simple cases that the organization can acquire meaning
    and life of its own and begin to transcend the parts from which it is
    made.

    What physical science thus has to tell us is that the whole being more
    than the sum of its parts is not merely a concept but a physical
    phenomenon. Nature is regulated not only by a microscopic rule base
    but by powerful and general principles of organization. Some of these
    principles are known, but the vast majority are not. New ones are
    being discovered all the time. At higher levels of sophistication the
    cause-and-effect relationships are harder to document, but there is no
    evidence that the hierarchical descent of law found in the primitive
    world is superseded by anything else. Thus if a simple physical
    phenomenon can become effectively independent of the more fundamental
    laws from which it descends, so can we. I am carbon, but I need not
    have been. I have a meaning transcending the atoms from which I am
    made.

    I am increasingly persuaded that all physical law we know about has
    collective origins, not just some of it. In other words, the
    distinction between fundamental laws and the laws descending from them
    is a myth -- as is therefore the idea of mastery of the universe
    through mathematics solely. Physical law cannot generally be
    anticipated by pure thought, but must be discovered experimentally,
    because control of nature is achieved only when nature allows this
    through a principle of organization.

    One might subtitle this thesis the end of reductionism (the belief
    that things will necessarily be clarified when they are divided down
    into smaller and smaller component parts), but that would not be quite
    accurate. All physicists are reductionists at heart, myself included.
    I do not wish to impugn reductionism so much as establish its proper
    place in the grand scheme of things.

    To defend my assertion I must openly discuss some shocking ideas: the
    vacuum of space-time as "matter," the possibility that relativity is
    not fundamental, the collective nature of computability,
    epistemological barriers to theoretical knowledge, similar barriers to
    experimental falsification, and the mythological nature of important
    parts of modern theoretical physics. The radicalness is, of course,
    partly a stage prop, for science, as an experimental undertaking,
    cannot be radical or conservative but only faithful to the facts. But
    these larger conceptual issues, which are not science at all but
    philosophy, are often what most interest us because they are what we
    call upon to weigh merit, write laws, and make choices in our lives.

    The objective, then, is not to make controversy for the sake of itself
    but to help us see clearly what science has become. To do this we must
    forcibly separate science's function as the facilitator of technology
    from its function as a means of understanding things -- including
    ourselves. The world we actually inhabit, as opposed to the happy
    idealization of modern scientific mythology, is filled with wonderful
    and important things we have not yet seen because we have not looked,
    or have not been able to look because of technical limitations. The
    great power of science is its ability, through brutal objectivity, to
    reveal to us truth we did not anticipate. In this it continues to be
    invaluable, and one of the greatest of human creations.

    The idea of science as a great frontier is timeless. While there are
    clearly many nonscientific sources of adventure left, science is the
    unique place where genuine wildness may still be found. The wildness
    in question is not the lurid technological opportunism to which modern
    societies seem so hopelessly addicted but rather the pristine natural
    world that existed before humans arrived -- the vast openness of the
    lone rider splashing across the stream with three pack animals under
    the gaze of mighty peaks. It is the choreography of ecologies, the
    stately evolution of minerals in the earth, the motion of the heavens,
    and the birth and death of stars. Rumors of its death, to paraphrase
    Mark Twain, are greatly exaggerated.

    My particular branch of science, theoretical physics, is concerned
    with the ultimate causes of things. Physicists have no monopoly on
    ultimate causes, of course, for everyone is concerned with them to
    some extent. I suspect it is an atavistic trait acquired long ago in
    Africa for surviving in a physical world in which there actually are
    causes and effects -- for example between proximity to lions and being
    eaten. We are built to look for causal relations between things and to
    be deeply satisfied when we discover a rule with cascading
    implications. We are also built to be impatient with the opposite
    -- forests of facts from which we cannot extract any meaning. All of
    us secretly wish for an ultimate theory, a master rule set from which
    all truth would flow and which could forever free us from the
    frustration of dealing with facts. Its concern for ultimate causes
    gives theoretical physics a special appeal even to nonscientists, even
    though it is by most standards technical and abstruse.

    Learning about these things is an intellectual roller-coaster ride.
    First you find that your wish for an ultimate theory at the level of
    people-scale phenomena has been fulfilled. We are the proud owners of
    a set of mathematical relationships that, as far as we know, account
    for everything in the natural world bigger than an atomic nucleus.
    They are very simple and beautiful and can be written in two or three
    lines. But then you find that this simplicity is highly misleading.
    The equations are devilishly difficult to manipulate and impossible to
    actually solve in all but a small handful of instances. Demonstrating
    that they are correct requires arguments that are lengthy, subtle, and
    quantitative. While the basic ideas were invented by Schrödinger,
    Bohr, and Heisenberg in the 1920s, it was not until powerful
    electronic computers were developed and armies of technically
    competent people were generated by governments that these ideas could
    be tested quantitatively against experiment over a wide range of
    conditions.

    Thus 80 years after the discovery of the ultimate theory we find
    ourselves in difficulty. The repeated, detailed experimental
    confirmation of these relationships has now officially closed the
    frontier of reductionism at the level of everyday things. Like the
    closing of the American frontier, this is a significant cultural
    event, causing thoughtful people everywhere to debate what it means
    for the future of knowledge. At the same time, the list of even very
    simple things found "too difficult" to describe with these equations
    continues to lengthen alarmingly.

    Those of us on the real frontier listening to the coyotes howl at
    night find ourselves chuckling over all of this. There are few things
    a real frontiersman finds more entertaining than the insights from
    people back in civilization who can barely find the supermarket. I
    find this moment in history charmingly similar to Lewis and Clark's
    wintering on the Columbia estuary. Through grit and determination
    their party had pushed its way across a continent, only to discover
    that the value had not been in reaching the sea but in the journey
    itself. The official frontier at that time was a legal fiction having
    more to do with property rights and homesteading policy than with a
    confrontation with nature. The same is true today. The real frontier,
    inherently wild, may be found right outside the door, if one only
    cares to look.

    The important laws we know about are, without exception, serendipitous
    discoveries rather than deductions. This is fully compatible with
    one's everyday experience. The world is filled with sophisticated
    regularities and causal relationships that can be quantified, for this
    is how we are able to make sense of things and exploit nature to our
    own ends. But the discovery of these relationships is annoyingly
    unpredictable and certainly not anticipated by scientific experts.
    This common-sense view continues to hold when the matter is examined
    more carefully and quantitatively. It turns out that our mastery of
    the universe is largely a bluff -- all hat and no cattle. The argument
    that all the important laws of nature are known is part of this bluff.

    Thus the end of knowledge and the closing of the frontier it
    symbolizes is not a looming crisis at all, but merely one of many
    embarrassing fits of hubris in civilization's long history. In the end
    it will pass away and be forgotten. Ours is not the first generation
    to struggle to understand the organizational laws of the frontier,
    deceive itself that it has succeeded, and go to its grave having
    failed. One would be wise to be humble, like the Irish fisherman
    observing quietly that the sea was so wide and his boat so small. The
    wildness we all need to live, grow, and define ourselves is alive and
    well, and its glorious laws are all around.

    Robert B. Laughlin is a professor of physics at Stanford University
    and a 1998 Nobel laureate in physics. He is on leave from Stanford to
    serve as president of the Korea Advanced Institute of Science and
    Technology, in Taejon, South Korea. This essay is adapted from A
    Different Universe: Reinventing Physics From the Bottom Down, to be
    published in March by Basic Books.


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