Re: Scientific American on complexity

Stephen Jones (sjones@iinet.com.au)
Tue, 20 Jun 95 21:54:21 EDT

Art

On Wed, 14 Jun 1995 15:54:16 -0700 you wrote:

>S. Jones writes:
SJ>Thanks. We are 2-3 months behind here with Scientific American so I
>look forward to the June issue.
>Perhaps you can post some quotes?
>
AC>The following quotes are subject to the following stipulations:
>
>1. All quotes are lifted out of context.
>
>2. No attempt has been made to use the quotes in a manner consistent with
>the authors intent.
>
>3. All quotes were chosen from the biased perspective of the correspondent
>that complexity will soon join the ranks of catastrophe theory and chaos
>theory as interesting but dead end streets toward unified theories of
>anything.

Well, that's certainly a novel way to head off criticism! <g>

AC>O.K. here goes:
>The article subtitle: "Can science achieve a unified theory of
>complex systems? Even at the Santa Fe Institute, some researchers
>have their doubts."

To be fair, one would have thought that having doubts is what science
should be all about?

AC>David Liddle, chairman of the Board of the Institute says "There is
>a lot to be proud of". "There certainly is, at least from a public
>relations standpoint" states Horgan.

One wonders how much of what passes for science these days is PR?

AC>"What Liddle does not say is that even some scientists associated
>with the institute are beginning to fret over the gap between such
>rhetoric and reality."

One wonders why there should be any "rhetoric" at all.

AC>Jack D. Cowan helped found the Institute and remains on the board,
>He thinks:
>"some Santa Fe theoretists exhibit too high a 'mouth-to-brain ratio'
>for his taste. "'There has been tremendous hype' he grumbles."

Selective though this may be, a pattern seems to be emerging. And it
is no one of Glenn's little shapes!

AC>"Cowan finds some work at Santa Fe interesting and important, but
>he deplores the tendency of research there 'to degenerate into
>computer hacking'. Too many simulatore also suffer from what Cowan
>calls the reminiscence syndrome. 'They say, "Look, isn't this
>reminiscent of a biological or physical phenomenon!" They jump in
>right away as if it's a decent model for the phenomenon, and usually,
>of course it's just got some accidental features that make it look
>like something.'

This is not new. Read Dawkins discovery of his Biomorphs in The Blind
Watchmaker!

AC>The major discovery to emerge from the institute thus far, Cowan
>suggests, is that "it's very hard to do science on complex systems."

How much money have the consumed to come up with that startling
finding!

AC>"Some residents blame the media for the exaggerated claims
>associated with the institute. 'Ninety percent of it came from
>journalists.' Arthur [nonlinear economist] asserts.

One wonders what the 10% remaining is then.

AC>Yet the
>economist cannot help but play the evangelist. 'If Darwin had had a
>computer on his desk,' he exclaims, 'who knows what he could have
>discovered!' What indeed: Charles Darwin might have discovered a
>great deal about computers and very little about nature."

Indeed! If Darwin could extrapolate all of nature from a few
islands in the Pacific and a flock of pigeons, just think what he
could have done with a computer! <g>

AC>An interesting discussion ensues about the inability to define
>complexity. Ten of some 31 or more current and often mutually
>confuting definitions are listed in a sidebar.

I'm glad someone admits it. I'm still trying to get the boffins on the
Australian fidonet Creation v Evolution echo to define exactly what is
the difference between order and complexity.

AC>John Maynard Smith, who took an early interest in the institute,
>and has twice spent a week visiting there, "...concluded that
>artificial life [research at the institute] is 'basically a fact-free
>science.' During his last visit, he recalls, 'the only time a fact
>was mentioned was when I mentioned it, and that was considered to be
>in rather bad taste.'"

This raises the interesting point that just about anything can be a
"science" as long as it doesn't have anything to do with creation!

AC>Regarding Bak's sandpile:
>"...Sidney R. Nagel of the University of Chicago asserts that Bak's
>model does not even provide a very good description of a sandpile.
>He and other workers at Chicago found that their sandpile tended to
>oscillate between immobility and large-scale avalanches rather than
>displaying power-law behavior."

Does this mean that the following:

--------------------------------------------------------------------
"Can we model Darwin?

Reducing Darwin to a set of equations may never be possible. But a
promising computer model shows that mass extinctions could have
happened naturally as a consequence of the simple principles of
evolution

Per Bak, Henrik Flyvbjerg and Kim Sneppen

PHYSICS has been immensely successful in finding mathematical
laws that help it describe the Universe. All matter obeys
Einstein's equations of general relativity. The way elementary
particles interact are described mathematically by the
Standard Model. And Schrodinger's equation describes atoms,
their nuclei, chemical compounds, crystals and many other
states of matter. Even the life and death of stars have well
established formulas.

But when it comes to the most complex system, mathematics has so far
failed. Life on Earth involves a myriad species interacting with each
other in ways that constantly change as they evolve, differentiate and
become extinct. There are no "Darwin's equations" to describe the
evolution of life on Earth into complex, interacting ecologies.

Scientists accept that Darwin and his followers have convincingly
described the principles governing the evolution of life. Darwin's
theory of natural selection identifies in a qualitative way the cause
of evolutionary change: natural selection operating through a
struggle among individual organisms for reproductive success. But the
absence of a more quantitative framework means that Darwin's
principles have not been tested against observation in the same
rigorous manner as physical laws. This also means that there is no
way of predicting the outcome of Darwin's theory.

Bursts of change

Nevertheless, most scientists believe that life-or evolution can, in
principle, be described by the laws of physics. So far, the problem
has simply seemed too big and scientists have concentrated on parts
of the system, creating such disciplines as population biology and
biogeography. This approach has been extremely successful in
explaining many of the details of evolution. But we argue that
evolution must be viewed as a whole, and that an understanding of it
may not lie in those details. Over the past decade, for the first
time, new mathematical ideas used to describe the behaviour of large,
interacting, dynamical systems have begun to make this holistic
approach possible.

The big new idea in this approach was conceived in the late 1980s by
Per Bak, a physicist at Brookhaven National Laboratory in New York
state, and Stuart Kauffman, a theoretical biologist at the Santa Fe
Institute in New Mexico. They argued that life is a dynamical system
which, far from existing in a state of balance or equilibrium,
organises spontaneously into a characteristic and much more precarious
"critical" state.

Surprisingly, this model of evolution predicts that life does not
evolve gradually but intermittently, with long periods of inactivity
or stasis, interrupted by bursts of change which are characterised by
mass extinctions and the emergence of many new species. It is just
this pattern that many palaeontologists say exists in nature."

(Bak P., et al, "Can we model Darwin?", New Scientist, 12 March 1994,
p36).
--------------------------------------------------------------------

is just a model designed to fit a theory? <g>

I found this intriguing:

"When Bak and Henrik Flyvbjerg...applied mathematics to this model, it
appeared here, too, the criticality relied ON A JUDICIOUS CHOICE OF
MODEL...Increasingly it seemed impossible to find a model of evolution
that mirrored the real world WITHOUT CHEATING" (p38 emphasis mine)

The end of the article might be interesting to Glenn:

"We have not found the equivalence of Darwin's missing equations-we
are not even close to doing that. But we do have a simple model for a
vastly simplified Darwinian evolution. This model is a mathematical
model, formulated as a set of equations that can be solved on a
computer. Despite its simplicity, the model has already taught us that
punctuated equilibrium, stasis, and intermittency can be direct
consequences of of simple principles of evolution, as expressed by
Darwin. No extra explanations beyond those principles are required"
(p39).

Maybe I am not among the initiated, by why does the above paragraph
seem like a load of self-contradictory codswallop? How can it in one
breath claim to "be not even close", be "vastly simplified", yet be
able to say that "no extra explanations" are required? It sounds
suspiciously like a giant con:

1. Chose the current most popular theory of evolution.

2. Apply for a Government grant.

3. Design a computer program that will model the theory.

4. If it doesn't fit the theory, keep refining it.

5. When it does eventually fit the theory, then stop.

6. Announce to the world the amazing results that the program
models the theory!

7. Collect Government grant and fame!

I am reminded of something Dawkins says with his customary
objectivity in the things of God <g>:

"Nearly all peoples have developed their own creation myth, and the
Genesis story is just the one that happened to have been adopted by
one particular tribe of Middle Eastern herders. It has no more
special status than the belief of a particular West African tribe that
the world was created from the excrement of ants." (Dawkins R., "The
Blind Watchmaker", 1991, Penguin, p316)

Maybe in the final analysis the West African tribe's model is better
at fitting reality than the Santa Fe Institute's sandpile? <g>

AC>There's lots more but these objective random samples will serve to
>stimulate you to read the article.

I can hardly wait. Thanks for the appetiser.

God bless.

Stephen