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A Tale of Two Directions

Yi-Cheng Zhang

posted on 01 April 2001

The statistical Mechanics Community used to be a unified fraternality
inside the greater
physics discipline. We recall that in the golden eighties there were such
romantic themes
as the then-emergent field: pattern formation, fractals, DLA, SOC,
which even
some of the most prominent physicists gravitated. No longer. The Community
as we know
it doesn't exist any more, even though grand meetings like Statphys21 still
hundreds, but it seems more like an Old-Boys-Club than a place to look up
for clues of new
directions and inspirations.

However, on the two sides of the Pond (Atlantic) two new directions have
emerged, quite
distinct one from the other. In the US there is a sizable community of
former statitistians who,
instead of playing with sand piles (SOC) or directed polymers, have become
experts in Bio-informatics
of a sort. I just came back from a three weeks stay at the workshop hosted at ITP,
Santa Barbara. I met many of my former
colleagues who seemed overnight to have become experts in such matters as
Protein foldings,
Genomics, DNA coding, etc. I tried to follow some of the talks, only to
realize that I'd need tremendous
stamina to catch up on the basic facts. Quite different than economics it's definitively
a handicap no having gone through the training that
constitutes a biology curriculum.
Yet I find it amazing that some of these physicists are already so deep in
this field---not that I can confidently judge---but only forming an opinion
by listening to
the question-answer sections at the ITP workshop. Even guys from Celera
sometimes had to bow, to admit cutting corners and
begging for mercy.

We shouldn't slight ourselves. For reasons we all know (or don't really
know?), that on the Old
Continent the turn is toward another direction: Econophysics. The Last conference dedicated to such
a topic just ended in Febuary in Prague, which was one of the series that
started in Budapest in 1997.
Differing from their US colleagues, Europe-based physicists seem at ease in
modeling economical, social
processes, which are at another level of complexity of life. Initial
efforts were mainly directed toward finance, as
can be attested by the conference talks. For certain, econophysics even
became a synonym for financial engineering.
It's understandable why interest in finance was overwhelming at the
beginning: much data available, and physicists, esp.
statisticians, love numbers, lots of them. But recently the trend is slowly
shifting toward modeling fundamental
economic processes. Another strong point of Physics is to simplify reality
but not too much, to build
simple and yet somewhat realistic models. In this new direction there are
models about the web, the internet, market
behaviors and various game theories.

There are caveats to the above story of two separate ways on the two sides
of the pond. Econophysics, even the word
was attributed to Stanley, and his group is largest. In the US some very
interesting researches in fields like Small Worlds and
internet structures are actively pursued (B. Huberman, A. Barabasi et al).
On the other hand, some Europeans are experts in
bio-informatics like Protein Folding (A. Maritan, De Los Rios, R. Livi et
al). And there could be unexpected cross-fertilizations
: People told me at ITP workshop that the information theory model that
Sergei Maslov and I have developed
for knowledge networks can be actually employed for gene and protein
alignments (T. Hwa, Y. Yu et al)...

Anyway, there is no reason to cry over the lost unity, and one thing in
common in both of the trends is that we all somehow
embarked on a path that even Steve Hawking have not failed to notice. He
recently said: "I think the next century will be
the century of Complexity". Probably he is right.