Introducing Bruce Gregory, part three of three

Introducing Bruce Gregory, Part three of three

Languages and Metalanguages
    How could we compare a theory with the world? A physicist's
theory is a collection of mathematical formulas, and the world .
. . well, the world is something completely different. Then how
can a theory refer to the world? If I say, 'The dog is named
Willard,' I am surely using the word Willard to refer to a real
animal. There is obviously a difference between the word Wit d
and the dog. When I say, "Electricity is related to electrons in
the wire," am I not doing exactly the same thing? Am I not using
the word electrons to refer to something out there in the world?
    
    In order to talk about the relationship between a theory and
the world, we can make use of what a logician calls a
metalanguage. A metalanguage is a way of talking about a language
while using language and, we hope, not becoming too confused in
the process. For example, if I say, 'The French word for dog is
Calm,' I am using English as a metalanguage to talk about words
in the French language.
    
    Let us look at the statement, 'The word electron refers to a
subatomic particle.' In this case, the language and the
metalanguage are both English. We can discriminate between the
words we are talking about and the words we are using to do the
talking by putting the former in italics. The sentence in the
metalanguage tells us the word electron refers to something in
the world called a subatomic particle. But notice that reference
is a relationship between the word electron and the words
subatomic particle, not between words and something that is not
words. The observations with which physicists compare their
predictions are not some mute expression of the world. They are
symbolic and gain their meaning and value in a system of inter-
pretation. No experiment, in Born's words, has any meaning at all
until it is interpreted by a theory. Then how do we ever manage
to talk about the world?
    
    If you ask me to bring you a book, you judge the success of
your request by the arrival of the book. If I bring you the wrong
book, you are not likely to feel that there was some failure of
your words to correspond to the world but rather that you were
not specific enough or that I did not know which book you meant.
No discussion of the nature of reference would improve the
situation, and a discussion of the reality of books would be even
less likely to be helpful. Books are real, not because of some
mystical connection between language and the world, but because
you can ask me to bring you a book and my action can fulfill your
expectation. That expectation and its fulfillment are made
possible by our community of shared assumptions, conventions, and
understandings ' our shared language. Unicorns are not 'real'
because our community has no expectations about living or dead
unicorns that can be fulfilled, only mythological ones. The
reality of unicorns is related to our use of the word unicorn.
Using the word every day would commit us to the existence of
"real' unicorns, just as using the word quark every day commits
physicists to the existence of quarks.
    
    If we question the existence of certain things, the
luminiferous ether and unicorns, for example, we question whether
these words continue to pay their way in our speech. If
luminiferous ether and unicorn fall into disuse, the ether and
unicorns are no longer real. But notice that we are sure that the
ether and unicorns were ever real. When we stopped using these
words, our new vocabulary seemingly reached back into the past
and eliminated any reality the luminiferous ether and unicorns
ever had. History is not as immutable as we might think; language
can apparently transform the past as readily as it shapes the
present and the future.
       Chapter 15
      
      THE LAST WORD
      
      It is the theory that decides what we can observe.
                           ALBERT EINSTEIN
      
      An electron is no more (and no less) hypothetical than
      a star.
                      SIR ARTHUR STANLEY EDDINGTON
      
      Three umpires were discussing their roles in the game of
baseball. The first umpire asserted, "I calls 'em the way I sees
'em." The next umpire, with even more confidence, and a more
metaphysical turn of mind said, 'I calls 'em the way they are!' But
the third umpire, displaying a familiarity with twentieth-century
physics, concluded the discussion with, 'They ain't nothin, until
I calls 'em!" The ball, the bat, and the plate do not create the
game; the rules create the game, and the umpire interprets the
rules, and in the process, creates the score. The players and the
fans have no doubt that the ball was either over the plate or not
over the plate, but the umpire's call, and not any fact of the
matter, creates a ball or a strike.
    
The Role of Language
    Implicit in the way we use language is the notion that
language points to a world beyond itself In the everyday world,
language points to trees, buildings, automobiles, cabbages, and
kings. But what kind of stuff is this everyday world made of?
    
    Surely the world is not really made up of supply and demand,
profit and loss, or democracy and communism. These are human ways
of characterizing experience; we want to know what the world is
like independent of human concepts. We want to know whether the
runner was really safe or out. If we want to know what the real
substance of the world is, we have to turn to the hard sciences,
and physics is the hardest science of all. If any science can
claim to know something about the way the world is put together,
physics can. So we have turned to physicists to find what the
world is really made of, and they have told us. But their answers
have hardly reassured those of us looking for certainty. In our
attempt to get to a world outside of language, we have apparently
wound up squarely in the net of language. When someone argued
with Niels Bohr that reality is more fundamental than language,
he responded, "We are suspended in language in such a way that we
cannot say what is up and what is down. The word 'reality' is
also a word, a word we must learn to use correctly.'
    
    At the heart of physics is the process of building models of
the world. Often these models have required the invention of new
mathematical languages. The models physicists build can never be
compared with the world, because as Einstein tells us, we do not
even know what that would mean. Rather, the predictions derived
from the models can be compared with observations of the world.
However, this comparison is by no means simple and
straightforward. For example, only by a chain of complex
reasoning can physicists link the tracks in a bubble chamber with
the existence of an invisible neutrino or equally invisible
quarks.
    
    The hallmark of the conversation of science is the
willingness to allow the agreement or disagreement between
predictions and observations to determine whether physicists are
satisfied with the theory they have or whether they try to build
a new theory ' that is, whether they continue to talk about the
world in one way or change to another. In physics, this fidelity
to observation started with Kepler, who threw away years of work
and centuries of conviction because his theory's predictions
differed from Tycho's observations by a fraction of a degree. The
importance of observation continues to the present day, when a
minute discrepancy between the observed and predicted energies
associated with the configuration of the electrons in hydrogen
atoms spurred the development of quantum field theory.
    
    To a physicist the world is comprehensible to the extent that
the world's behavior is predictable. In this sense, the ancient
astrologer's drive to predict the future survives in the modern
physicist. The difference between physics and most human
enterprises is the physicist's ability to use physical theories
to make predictions successfully. Despite the uncanny success of
mathematical models in making such predictions, the richness of
nature far exceeds physicists' ability to capture nature in a
mathematical simplification. Once physicists pass beyond the
simplest of systems, they find it incredibly difficult to make
predictions by solving the mathematical equations describing the
detailed behavior of the world. Instead, they are forced to work
with approximations and averages that sometimes allow them to
predict quite well how things will turn out and sometimes lead to
abysmal failures. Physics is the drive to predict the behavior of
a world stripped of most of its complications. Chemistry, with
its profusion of atoms and molecules interacting in intricate
ways, is more complex than physics, and biology is immensely
complex.
    
    The language of physics is well suited to talking about the
world at the most elementary level we can imagine, but it would
be silly to try to use the vocabulary of quarks and leptons to
talk about living things or social systems. Physics can perfectly
well explain that sunlight scattered by the molecules of gas in
the atmosphere produces the blue color of the sky, but attempting
to talk about the beauty of the sky in the language of quantum
electrodynamics seems hopeless: 'Physicists may one day have
found the answers to all physical questions, but not all
questions are physical questions.' Even in describing complex
physical situations, however, physicists are like novice chess
players who find themselves playing an international grand
master. Knowing the rules of the game hardly guarantees being
able to play a credible game ' much less emerging victorious.
    
    My dog can look in the direction of the sunset, but I somehow
doubt the sunset holds any beauty for her or that she even sees a
sunset. There is more to beauty than meets the eye. Beauty seems
to lie, less in the eye, and more in the mouth, in the language,
of the beholder. It is hard to argue that there is a fact about
beauty aside from our conventions and our language. Despite our
saying that the reaction we feel to beauty is a matter of feeling
or emotion, the beauty of the sunset seems to grow out of the
distinctions language makes possible. In the same way, the beauty
the physicist sees in the heart of nature is a result of the
distinctions made possible by the language of physics.
    
    For thousands of years questions have been raised about the
nature of reality. Is reality material or is it spiritual? Is
reality one or is it many? Is everything determined or is there
room for freedom? The answers have not proved persuasive, since
the questions are still being debated. Physics shows us a
different way to look at these questions ' a way that asks what
vocabulary, what theory, we should use to talk about the world.
The word should makes sense in terms of the ends we hope to
achieve. The question need not be whether reality is material or
spiritual; it can be, what follows from talking about reality in
one way or the other? What do we gain, and what price do we pay,
for adopting one vocabulary and giving up another?
    
    Like the Greek gods on Mount Olympus, the quarks and leptons
of the present day are a story. How long physicists will continue
to tell the story outlined in this book depends on how long it
serves a useful purpose. Quarks and leptons are a fa‡on de
parler. They are no different in this respect from houses, trees,
or stars. Language tells us what the world is made of, not
because language somehow accurately captures a world independent
of language, but because it is the heart of our way of dealing
with the world. When we create a new way of talking about the
world, we virtually create a new world. This observation is no
more profound, nor any less profound, than saying that the
questions we ask determine, not the content of the answers we
will get, but what will count as an answer. When a pickpocket
encounters a saint, all the pickpocket sees are the saint's
pockets.
    
    Just because all we have are stories does not mean that all
the stories we have are equal. A story does not have intrinsic
value; it has value only to the extent that it serves a purpose,
and the stories of physics have served their purposes very well
indeed. Physicists have gained enormous predictive power by
letting the agreement between predictions and observations tell
them which ways of talking to keep, and which to discard.
    
    Explanations, no matter how wonderful, are stories about how
we got from where we were to where we are. Clearly some
explanations are more compelling than others. But the history of
physics shows us that we lack the ability to judge whether an
explanation is powerful unless we can tell what its consequences
are. Explanations that cannot predict ' and predict accurately '
are like Kipling's just-so stories, in Heisenberg's words,
'matters of personal belief' Viewed from this perspective, most
of our explanations are just-so stories. They function in various
ways, including amusing or annoying us, alienating us or building
solidarity. It is hard, however, to maintain that these stories
succeed in doing what physics has not been able to do ' to
picture the world as it somehow really is rather than as it seems
to us to be. We might be better off regarding our most cherished
beliefs as ways of talking about the world, rather than revealed
truths.
    
    Quantum mechanics shows us that there are no facts with
regard to the precise paths of electrons. While it is true that
what we say determines what kinds of things will turn out to be
facts in the matter, we are not free to say anything we like ' at
least not if we want to talk physics. For, as we have seen, the
world sharply constrains the kind of things physicists can say
and still make accurate predictions.
    
    Outside of the structure provided by a language, it does not
make much sense to say there are 'really" facts. Quarks and
leptons are interpretations of mathematical expressions. A
similar statement applies to forces and quantum fields. What can
count as a fact is determined by our language, not by the world.
In Einstein's words, 'It is the theory that decides what we can
observe." The German philosopher Martin Heidegger put the matter
more poetically, 'Language is the house of being." The language
we use tells us the kind of a world we can expect to find.
    
    If, as Einstein told us, there is no ultimate theory, no
ultimate language, then there is no ultimate fact about the stuff
the world is made of But if this is so, how much sense does it
make to insist that there is a fact, apart from the language we
use, with regard to anything else? Physics has a clear criterion
for the choice of a language ' physicists choose the language
that allows their predictions most closely to fit their
observations. But outside of physics, outside of science, what
criteria do we employ to determine the vocabulary we will use and
the 'facts" we will therefore find?
    
    Watching the changing way physicists talk about electrons,
for example, suggests that the notion we seem to have that names
are like labels on museum displays does not hold up very well. In
the world of physics, names seem more like the descriptions of
animals that are free to roam in a modern zoo. Furthermore, the
descriptions of these occupants were not written by an omniscient
curator, but rather jotted down by earlier visitors, perhaps
describing something only glimpsed in the distance. It is
sometimes hard to tell exactly what these phrases describe or if
we are looking at exactly the same animals the earlier visitors
saw.
    
    The world is not infinitely fluid. Physicists today can
perform the same experiments with cathode-ray tubes that Thomson
first performed almost a hundred years ago. They will see similar
effects and be able to describe them almost exactly as he did.
Thomson would also have relatively little difficulty
understanding the principles behind a modern television set. What
would be very different, however, is what Thomson and a modern
physicist would my about the observations they make ' the
language they would use to interpret their findings. It is in
this sense that modern physicists live in a world different from
Thomson's.
    
    Reference is a word, and like any word it has to be used
carefully. Our language commits us to the existence of house,
dogs, fire engines, and quarks. When we finally settle down into
the language that we Ibis to get our day-to-day work done, the
words in this language tell us what is real. As our vocabulary
changes, so does the world.
    
    Perhaps we can now appreciate what Bohr meant when he said,
"But if anybody says he can think about quantum problems without
getting giddy, that only shows he has not understood the first
thing about them.' Physics shows us that while the world shapes
us, the language that we use shapes the world. We might even say
the language that we air shapes the world, for language
undoubtedly defines us more profoundly than we can begin to
imagine.

      EPILOGUE
      
      Setsuji-ichimotsu soku fuchu
      'Begin to preach, and the point is lost.'
      
      ZENRIN KUSHU

    The development of physics led Bohr, Einstein, and Heisenberg
to the conclusion that, despite how it may seem, physics is not
an undistorted picture of an already-made world but a way of
talking about the world. The development of the science since the
time when these founders of twentieth-century physics did their
pioneering work has done nothing to undermine this insight. No
slavish reconstruction of a ready-made world, physics is an
imaginative vision of how the world might be put together.
    
    Although this point is by now obvious, I want to be explicit:
Just as there seems to be no 'right" way to talk about the world,
there is no "right' way to talk about physics, including what I
say in this book ' that physics is a way of tallying about the
world. The benefit of using language in this way comes from the
advantages the perspective provides. If we find this approach
valuable, we will continue to say that physics and the wider
world of science and other human creations are ways of talking.
If not, we can always choose to ignore Einstein's admonition and
continue to see these enterprises, "not as creations of thought,
but as given realities.'

- END -

···

--------------------------

Bruce knows far more about CSG people than we know about him.
Bruce has read all of the PCT demo disk texts as well as the PCT
literature, and is working his way through the 1993 and 1994
conference videos. I take considerable satisfaction in seeing new
people taking advantage of the many man-weeks I spent pulling
together the references I have contributed. It all adds up.
Newcomers are able to pick up a comprehensive understanding of
PCT faster than ever -- when they want to. Bruce Gregory wants
to.

Having read Bruce's book during a vacation trip, I told Bruce I
was particularly anxious to get his reaction to my presentations
in 1994 on explanations and memory. I thought that in some
aspects, I dealt with the same basic concepts Bruce deals with.
By the way, for those who remember the video _A Private
Universe_, which I borrowed to show in 1994: Bruce's outfit
produced that video.

Here are two recent posts from Bruce to me, which I would like to
share.

-----------

from: "Bruce Gregory" <gregory@cf4.harvard.edu>
Organization: Center for Astrophysics
To: Dag Forssell <forssell@scvnet.com>
Date: Mon, 1 Jul 1996 11:01:56 EST

Dag,

I finally made the time to finish the first 1994 tape. I liked
your presentations very much and agree with almost everything you
said. (I don't share your view that the uncertainty principle is
likely to be replaced. The principle lies at the heart of
quantum mechanics. If it went, so would most of modern physics.
One way to think of the principle is in regard to the path of a
photon. If we could determine this path more accurately than the
principle allows, interference phenomena would be impossible. I
can say more about this, but I doubt you are that committed to
your aside.) I find it helpful to avoid the use of "true" when
describing theories, simply because people become uncomfortable
when what was once "true" becomes "untrue" and think that some
kind of relativism is involved. All we can really say, as Isaac?
pointed out, is that the theory we now accept is the best we have
been able to come up with, and to point out its limitations as
far as we know them (as you do when discussing HPCT).

I also liked your discussion of the role of memory. I am sending
you a copy of a short piece I wrote few months ago in which I
address this subject in terms of "stories" and the role they play
in understanding. Neither Bill nor Rick are particularly
concerned with learning as contrasted with performance (I can't
blame them, performance is hard enough to deal with!). For this
reason, they are less concerned with the role of memory, I
suspect.

. . . . Scott Adams new book _The Dilbert Principle_ is a
wonderful expose of what happens when you try to control other
control systems. His recommendations in the last chapter a
sensible and completely in alignment with knowing how to treat
autonomous control systems.

I was also very impressed with Tom Bourbon's demonstrations of
cooperative control. It has given me a lot to think about as
far as teaching and learning are concerned.

Best wishes, Bruce

------------------------

Date: Sat, 6 Jul 1996 20:12:41 GMT
Subject: CSG 1994 Meeting

Dag,

I just finished watching Bill Powers "On the Method of Levels."
Truly OUTRAGEOUS. (I use word in its sense of extravagant and
extraordinary.) I have lived much of my life between two camps.
In one camp I express my "humanistic" side, but keep my
"scientific" side out of sight. In the other camp, I do the
opposite. At one level, I have always known that these
dimensions were not incompatible, but I never found a wholly
satisfactory way to express their unity. Bill, of course, does
just this and does it completely effortlessly. My reaction is to
say, "Oh, that's how its done. I get it now." And indeed I do.
It is indeed wonderful to get to know you all. I am committed to
repay some portion of all I have gained by making some small
contribution to our common effort.

Best wishes, Bruce

p.s. My video player has some problem dealing with the long play
tapes. The sound is fine, but the picture is unstable. At some
point I will have to take time to get it adjusted. Either that,
or I'll treat the tapes as audio sources. With all the commuting
I do, listening to them would be no problem at all...

-----------------

Best, Dag