94-11-18:  PHYSICIST GELL-MANN SEEKS BASIS OF COMPLEXITY


     Murray Gell-Mann, winner of the 1969 Nobel Prize in
Physics and an intellectual 'jack-of-all-trades,' spoke to a
capacity crowd in the Life-Sciences auditorium Oct. 26 on the
relationships between simplicity and complexity as part of a
seminar series on transformations sponsored by the
Commonwealth Center for Literary and Cultural Change. Mr.
Gell-Mann, whose work in theoretical physics led to the
discovery of the 'quark' (a basic building block of all atomic
nuclei), is professor emeritus at the California Institute of
Technology and a founder of the Santa Fe Institute, an eclectic
organization devoted to research on patterns of simplicity and
complexity in everything from physics to economics.

"The world of the quark has everything to do with a jaguar
circling in the night," said Mr. Gell-Mann, quoting his friend,
the poet Arthur Sze. This line not only inspired the title of Mr.
Gell-Mann's recent book, "The Quark and the Jaguar", but also
epitomizes his intuition that simple, fundamental laws
governing all matter (symbolized by the quark) are related to
what he calls "complex adaptive systems" (symbolized by the
jaguar). Spelling out just what form such relationships take
has been the major task of Mr. Gell-Mann and his colleagues at
the Santa Fe Institute. 

"Regularity" and "accidental" are two key concepts in Mr.
Gell-Mann's description of what he calls "effective" (or true)
complexity. Seeking a good definition of complexity is not an
easy project, as Mr. Gell-Mann demonstrated. "Simplicity,"
wrote Mr. Gell-Mann, "refers to the absence (or near absence)
of complexity. Whereas the former word is derived from an
expression meaning 'once folded,' the latter comes from an
expression meaning 'braided together.'" Complexity arises from
the braiding of regular and accidental events. 

Regular features of a system can be described succinctly, as
Mr. Gell-Mann illustrated with reference to his necktie,
patterned with regularly spaced spouting whales on a
solid-color background. He then distinguished between
non-meaningful accidents, such as the pathway a gas molecule
takes after colliding with another molecule, and meaningful, or
"frozen" accidents, such as the death of Arthur, Henry VIII's
elder brother. This chance happening, which allowed Henry
rather than Arthur to assume the throne of England, ultimately
led to such monumental events as the founding of the Church of
England.

Complex adaptive systems, Mr. Gell-Mann explained, include
everything from colonies of bacteria to a child learning his
native language to stock brokers on Wall Street. All adaptive
systems can take in information about their environment,
identify regularities in the data, condense these regularities
into rules, or "schemata" and then act on the basis of these
schemata. Furthermore, the specific actions taken lead to
consequences that either tend to maintain or to destroy the
system. In short, complex adaptive systems "learn," while
equally complex, but non-adaptive systems, such as galaxies,
do not.

Mr. Gell-Mann lamented the fact that studies of complex
adaptive systems are not adequately rewarded in typical
academies. "The rewards for making connections are not as big
as for making discoveries on the edge of knowledge," Mr. Gell-
Mann said. "There is a real need for people who can range
across disciplines and who can take at least a crude look at