When is "Now"?, Science 
There have been a number of observations that lead to the
conclusion that our sensory apparatus works in a much more active
than technical recording devices like microphones and cameras. It
appears that anticipation in the sense of continuous forecasting
or prediction about what is going to happen on the sensory input
level is an essential part of our strategy to successfully
interact with a quickly changing environment.
A classic example where that can be demonstrated is the
flash-lag illusion: An object is moving in the visual field, at
one point a flash appears at the same location but it is perceived
as lagging behind the moving object. One interpretation of that
phenomenon is that we "see" the moving object where it would be if
it followed the trajectory and that therefore the visual system is
predictive. Another interpretation is that moving objects are
perceived faster than resting stimuli in the sense that our
perception of the resting flash in further in the past than that
of the moving object.
Eagleman and Sejnowski conducted a series of experiments that
are inconsistent with both interpretations. At the same time they
could pinpoint the moment of our subjective "now": What we see as
happening "now" depends on what happened during the time interval
of 80ms after (!) the occurrence of visual event.
In their experiments the researchers basically modified the
direction of the movement at the moment of the flash. For instance
when the object stops moving at the moment of the flash, then we
perceive it at the same location as the flash and not where we
would expect it if it had followed the original trajectory.
From an evolutionary standpoint this finding makes sense: After
an event happened at a certain moment, we still have 80ms to take
into account what happened next before we perceive it and start
interpreting the event. It is to be expected that these exciting
results from our visual interface to the world will have profound
endo-physics implications.
Motion
Integration and Postdiction in Visual
Awareness , David M.
Eagleman, Terrence J. Sejnowski, Science, Volume 287,
Number 5460,pp. 2036 - 2038, 2000
Rare Meteorite Promises Glimpse Into Dawn Of Creation, CNN
Al least since the series of movies like Deep Impact,
describing collisions of asteroids with planet earth, we are aware
of the real possibility of direct encounters with large objects
from outer space. One meteor with the estimated impact energy of
several kilotons of TNT (the Hiroshima bomb had an explosive yield
of about ten kilotons) burst into a fireball over the Yukon in
January. Fragments of the meteorite were found by an anonymous
collector and kept frozen in a plastic bag.
This turned out to be a lucky incidence for science since in
that condition volatile gases are preserved and can be analyzed.
(In other meteors only tiny gas fragments can be analyzed
that got trapped in "Buckyballs". Question: How did they get
in there? Are we sure these are just gas molecules and not
galaxies like the one on Orion's belt?) It is the first
time ever, that a meteor fragment was preserved and kept frozen in
a state similar to extra-terrestrial conditions.
These meteor fragments are especially precious since they
belong to a rare (2%) type of meteor made out of " carbonaceous
chondrite". This material contains a number of different organic
compounds, ingredients of the primordial soup from which living
systems emerged.
The analysis of the 4.5 billion year old fragment will give us
valuable information about the "dawn of creation" and will answer
questions about the chance of finding extra-terrestrial life. It
also will provide us with new insights into the possibility that
life on earth originally was spawned from outer space.
Scaling In Athletic World Records, Nature
In physics, scaling laws of phase transitions describe
some universal properties of the system under investigations (see
also ComDig 2000.0.1). More recently Feigenbaum could show that
transitions from order to chaos can take place through a
"period-doubling" scenario that also shows universal scaling
properties. The importance of these insights lies in the fact that
universal properties would not change even if the underlying
microscopic laws would be modified. This feature of complex
systems implies that a reductionistic analysis of microscopic laws
does not really help in understanding the behavior of the
macroscopic system.
Critical scaling phenomena have not found a lot of attention in
biological systems with the exception of scaling properties of the
size of biological organisms (see ComDig 2000.3.1.3).
Savaglio & Carbone study scaling properties of human
performance and they find some scaling behavior that seems to be
universal as well in the sense that the same critical exponents
are observed for different people independent of their individual
characteristics, apparently not even dependent on their gender.
The researchers investigated the data from world speed records on
land (running) and in water (swimming) over different standard
distances. The 100m Olympic running distance was excluded because
the average speed is too much influenced by the start. They asked
how the average speed depends on the length of the race. It is
intuitive that longer races tend to be run slower but it was not
known before how exactly fatigue slows runners and swimmers down
over time.
The astonishing results indicate that there seem to be two
different universal scaling exponents involved: As one would
expect from intuition, the average speed of a 800m race is
relatively much slower than that of a 200m race compared to the
speed difference between, say, between races of 800m and 5000m.
For men the speed records for the three distances are 37:28:24
km/h i.e. the average speed in a 200m race is about 30% faster
than in a 800m race but only about 15% slower in a 5000m race.
This difference is a consequence of the fact that there is a
"crossover" in scaling behavior between two and three minutes of
running/swimming. This is in nice agreement with the well-known
fact that at about that time the body switches from anaerobic to
aerobic metabolism.
Reforming the Patent System, Science
Science and technology in modern society can be seen as
complex adaptive system with a tremendous economic and social
impact. The fastest growing stocks are most often technology
related mainly in the areas of the Internet, and biotechnology.
There are few groups within the US society that grow faster than
research outcomes one of them are intellectual property lawyers.
The legal costs connected to technological progress are stunning:
lawyer's costs to obtain a patent are around US$ 10,000 litigation
costs (per site) easily exceed US$ 1.5 million.
From complex systems we know that if one mode becomes unstable
and grows faster than other modes it tends to become an order
parameter and will dominate the dynamics of the systems. In that
sense patents laws play an important role in the fitness landscape
of research and innovation. It is in the clear interest of patent
lawyers that the number of patent grows as fast as possible,
independent of the content and qualities of the patents. Secondly,
from a lawyer's perspective the patents should be as broad and
unspecific as possible so that many competitors have a choice of
either to infringe the patent, pay a licensing fee, or go to
court. The latter option certainly the most favorable for the
lawyers.
Barton suggests a number of changes that he thinks will be more
in the interest of innovative progress and also in the interest of
society: raise the standards for issuing patents, protect research
by providing them with ways to use patented results as long as it
is not exploited economically, and lastly to make it easier to
legally challenge patents that have been issued by mistake or are
otherwise invalid.
Dynamics of Trust and Exclusion in Networks, SFI Working Papers
Abstract: Networks such as ethnic credit
associations, close-knit residential neighborhoods, 'old boy'
networks, and ethnically linked businesses play an important role
in economic life but have been little studied by economists. These
networks are often supported by cultural distinctions between
insiders and outsiders and engage in exclusionary practices which
we call parochialism.
We provide an economic analysis of parochial networks in
which the losses incurred by not trading with outsiders are offset
by an enhanced ability to enforce informal contracts by fostering
trust among insiders.
We first model one-shot social interactions among
self-regarding agents, demonstrating that trust (i.e., cooperating
without using information about one's trading partner) is a best
response in a mixed-strategy Nash equilibrium if the quality of
information about one's partner is sufficiently high. We show that
since larger networks have lower quality information about
specific individuals and greater trading opportunities, there may
be an optimal (payoff-maximizing) network size.
We then model the growth and decline of networks, as well as
their equilibrium size and number. We show that in the absence of
parochialism, networks may not exist, and the appropriate level of
parochialism may implement an optimal network size. Finally, we
explore the welfare implications and reasons for the evolutionary
success of exclusion on parochial and other grounds.
-
A historical dispute in the conceptual underpinnings of
evolution is the validity of the gene centered view of evolution.
We transcend this debate by formalizing the gene centered view as
a dynamic version of the mean field approximation. This
establishes the conditions under which it is applicable and when
it is not. In particular, it breaks down for trait divergence
which corresponds to symmetry breaking in evolving populations.
Using this understanding, we study the role of spontaneous
pattern formation in the creation and maintenance of biological
diversity. Preliminary analysis and simulations demonstrate that
spontaneous pattern formation in the presence of disruptive
selection increases the generation and duration of genetic
diversity. These patterns interact with boundary and internal
barrier structure so as to generate counter-intuitive increases in
diversity in patches with high perimeter-to-core ratios. This
effect is increasingly pronounced for organisms that exhibit a
restricted mating neighborhood.
The approach we use merges methodologies from statistical
physics with models of evolutionary processes. The appearance of
spontaneous pattern formation in spatially distributed populations
is directly analogous to symmetry breaking and coarsening in
conventional physics models, e.g. Ising models of magnets. Thus,
our approach is an extension of the methods developed in the study
of correlations in systems that undergo phase transitions through
symmetry breaking.
This research has immediate implications for the design of
protected habitats that can maintain or reverse the current
dramatic decrease in biodiversity. Moreover, this approach may
provide a new theory of both the origins of diversity and the
mechanisms of sympatric speciation.
Phase Transitions in a Model of Internet Traffic, SFI Working papers
Abstract: In a recent study, Ohira and Sawatari
presented a simple model of computer network traffic dynamics.
These authors showed that a phase transition point ispresent
separating the low- traffic phase with no congestion from the
congestion phase as the packet creation rate increases. We further
investigate this model by relaxing the network topology using a
random location of routers.
It is shown that the model exhibits nontrivial scaling
properties close to the critical point, which reproduce some of
the observed real Internet features. At criticality the net shows
maximum information transfer and efficiency. It is shown that some
of the key properties of this model are shared by highway traffic
models, as previously conjectured by some authors. The relevance
to Internet dynamics and to the performance of parallel arrays of
processors is discussed.
Introduction: The exchange of information in complex
networks and how these networks evolve in time has been receiving
increasing attention by physicists over the last years. In
particular, it has been shown that the growth dynamics of the
World Wide Web (WWW) follows some characteristic traits displayed
by generic models of growth in random graphs. The presence of
scaling in the distribution of connections between nodes of the
WWW or in the number of pages per web site are consistent with
other analyses involving the dynamical patterns displayed, such as
the download relaxation dynamics which also decays as a power
law.
Pushing The Frontiers Of Interdisciplinary Research, Nature
In a complex adaptive systems context innovation can be
seen as an evolutionary process that takes place on a number of
different time-scales: There is local adaptation following the
slope of a fitness landscape, there is crossover which expands the
dimension of the fitness landscape and there are random mutations
which has no limitations in terms of dimensions of fitness
landscapes but which therefore is also happening at the slowest
time-scale. For innovation in scientific research similar rules
seem to apply: It proceeds within given scientific disciplines
until the toolbox of that discipline is exploited and progress
slows down. Cross-fertilization from other disciplines is often
successful because it allows experts in their discipline to see a
problem from a new angle and how it is solved in different
contexts with the tools of other disciplines.
In the early eighties this insight led to the formation of a
number of interdisciplinary centers at government laboratories
(e.g. the Center for Non-Linear Studies of the Los Alamos National
Laboratory) and at universities (e.g. the Center for Complex
Systems Research at the University of Illinois in Urbana
Champaign).
It turned out, however, that just putting experts with "strong
departmental background" into the same room and make them talk to
each other (with the carrot of new funds as incentive) was in most
cases not overwhelmingly successful and collaborations were rather
superficial if they happened at all.
In the more than fifteen years of that first round of
experiments in interdisciplinary research non-linear science and
complexity research has made impressive progress with new insights
into many different areas of research.
It was recognized that complex systems show new emergent
properties that are not just linear super-positions of results
from the traditional disciplines. In spite of that success
academic hiring practices largely continued to count publications
in narrow, discipline-specific journals and contributions in
interdisciplinary research was not often considered to be very
relevant for the decisions of recruiting committees.
Today it seems that biology has reached a threshold for their
traditional methods and needs to find crossover with methods from
more quantitative disciplines. Since biology is intrinsically
dealing with complex adaptive systems one might hope that it is
recognized that for successful collaboration a solid understanding
of complex and non-linear systems is indispensable.
Systems Thinking and Modeling for a Complex World, NECSI book
From the preface:
This book introduces you to system dynamics modeling for the
analysis of policy and strategy, with a focus on business and
public policy applications. System dynamics is a perspective and
set of conceptual tools that enable us to understand the structure
and dynamics of complex systems. System dynamics is also a
rigorous modeling method that enables us to build formal computer
simulations of complex systems and use them to design more
effective policies and organizations. Together, these tools allow
us to create management flight simulators-microworlds where space
and time can be compressed and slowed so we can experience the
long-term side effects of decisions, speed learning, develop our
understanding of complex systems, and design structures and
strategies for greater success.
Features and Content University and graduate-level texts,
particularly those focused on business and public policy
applications, have not kept pace with the growth of the field.
This book is designed to provide thorough coverage of the field of
system dynamics today, by examining
- Systems thinking and the system dynamics worldview;
- Tools for systems thinking, including methods to elicit
and map the structure of complex systems and relate those
structures to their dynamics;
- Tools for modeling and simulation of complex systems;
- Procedures for testing and improving models;
- Guidelines for working with client teams and successful
implementation.
You will learn about the dynamics of complex systems,
including the structures that create growth, goal-seeking
behavior, oscillation and instability, S-shaped growth, overshoot
and collapse, path dependence, and other nonlinear dynamics.
Examples and applications include
- Corporate growth and stagnation,
- The diffusion of new technologies,
- The dynamics of infectious disease such as HIV/AIDS,
- Business cycles,
- Speculative bubbles,
- The use and reliability of forecasts,
- The design of supply chains in business and other
organizations,
- Service quality management,
- Transportation policy and traffic congestion,
- Project management and product development,
- and many others.
The goal of systems thinking and system dynamics modeling is
to improve our understanding of the ways in which an
organization's performance is related to its internal structure
and operating policies, including those of customers, competitors,
and suppliers and then to use that understanding to design high
leverage policies for success. To do so this book utilizes
- Process Points that provide practical advice for the
successful application of the tools in real organizations.
- Case studies of System Dynamics in Action that present
successful applications ranging from global warming and the war
on drugs to reengineering the supply chain of a major computer
firm, marketing strategy in the automobile industry, and
process improvement in the petrochemicals industry.
Common Ancestry Of Monkeys, Apes And Humans, Science Daily/NIU
Excerpts: For the first time, scientists have
discovered skeletal parts of an extinct primate that documents an
early phase in the evolution of monkeys, apes, and humans.
(…) Co-author Christopher Beard said the latest discovery is
important because it helps fill a major gap in the fossil record
of humans and their nearest relatives. "I hate to use the term
'missing link' because it's such a cliche, but these fossils
really do fill a wide gap that previously separated higher
primates, also known as anthropoids, from their prosimian
relatives," said Beard, who coordinates the American side of the
joint Sino-American expeditions that resulted in new fossil
discoveries. Living anthropoids include monkeys, apes and humans.
Living prosimians include lemurs, bush babies, lorises and
tarsiers.
The evolutionary origin of higher primates has stymied
paleontologists and primatologists for decades, because so little
was known regarding the ancestral anthropoid lineage until
recently. Modern primates possess a variety of anatomical
adaptations for moving through their environment--usually the
trunks and branches of trees in tropical and subtropical forests.
Many prosimians are renowned for their ability to leap and cling
to vertical tree trunks, while monkeys tend to walk on all fours
on the tops of branches. The anatomy of the fossilized ankle bones
of Eosimias show that this animal already preferred walking
quadrupedally on the tops of branches like living monkeys. In
addition to verifying that Eosimias is an early higher primate,
the new fossils help settle a longstanding debate about where the
anthropoid lineage arose on the primate family tree.
Previously, there were three main hypotheses regarding the
nearest relatives of anthropoids. Based on similarities in the
anatomy of their teeth, some scientists have argued that
anthropoids evolved from the lemur-like adapids. Genetic
similarities and the anatomy of living primates lead other
scientists to believe that living and fossil tarsiers are the
nearest evolutionary cousins of anthropoids. A third hypothesis
accepts an evolutionary relationship between anthropoids and
tarsiers, but posits that the split between these two lineages is
very ancient, dating to at least 55 million years ago. The new
ankle bones of Eosimias are similar to those of anthropoids and
fossil omomyids, a group widely believed to be extinct relatives
of tarsiers. "The oldest known skeletal remains of a higher
primate are inconsistent with the view that monkeys, apes and
humans evolved from the lemur-like adapids," Beard said, "but they
support a close evolutionary relationship between anthropoids and
tarsiers."
Scientists recovered the fossils from a commercial limestone
quarry about 100 miles west of Shanghai and from a locality in
Shanxi Province (China), along the Yellow River, about 350 miles
southeast of Beijing. The location of the discovery also is
significant, the researchers say. "Most scientists in my field
believe that if the ancestor of anthropoid primates is to be found
then it should come from Africa," Gebo said. "Thus, the bones of
Eosimias are important, as is its unusual location (Asia)." The
new fossils were recovered during a series of expeditions
organized by scientists from Carnegie Museum of Natural History in
Pittsburgh, Pennsylvania and the Institute of Vertebrate
Paleontology & Paleoanthropology in Beijing.
Genomic Medicine And The Future Of Health Care, Science
One of the defining characteristics of complex systems is
the fact that simple rules lead can lead to complicated or even
chaotic forms and behaviors. Especially systems that include the
possibility of chaotic attractors are typically "structurally
unstable" in the sense that tiny changes in the rules or initial
conditions can lead to qualitatively completely different
outcomes. Nevertheless there are sometimes universal properties of
the system that allow fairly good predictions of the outcomes that
are to be expected for certain types of changes in the simple
rules.
A similar situation can be found in the developments of
biological organisms: The relative simple rules encoded in the
genome lead to the vast complexity of the organism and its
functions. When some of these functions fail or if some cells grow
out of control of the rest of the organism, we call that a
disease. The big challenge for the new biology is genomic
medicine, i.e. to figure out how the genetic rules are linked to a
healthy organism.
From science fiction movies we know the risks of genetic
screening of infants into alpha and gamma humans. Sander points
out a number of benefits for the individual if that genomic link
can be made: Not only can we be warned about what genetic diseases
we have an increased risk to develop. One of the first
applications of genomic medicine most likely will not be genetic
drugs but a genetic diagnostic health monitoring system. We can
have a personalized health care in that we can screen the genetic
expressions in our body around the clock and via Internet screen
for signals that indicate the symptoms of a developing disease.
Everyone knows about the importance of early diagnostics but with
such a system new forms of "chrono-medicine" might become
feasible. Since gene expression changes continuously during the
day, we have to expect that potent medicines will have very
different effects depending on the gene-expression state of the
organism. Therefore timing of the medication could make a
tremendous difference.
The bottom line is that biology and medicine will enter an
"information-age" and we know from our experience that in
increased access to information rests tremendous power. Therefore
a challenge will be to make sure that the risk for misuse of this
new genomic information will be minimized.
Links & Snippets
This is an experimental column with items that don't fit
into the standard framework of the Complexity Digest. We want to
include "snippets" like letters to the editor and conference
announcements and "links" to complexity related websites with
brief comments and short excerpts (< 80 words) that are
permitted by copyright laws.
The Rural Life At the Edge of Order, New York Times
"The article struck me as an illustration of the
penetration of complexity ideas into general literature without
necessarily knowing that there is a specialized study." (Dean
LeBaron)
Excerpt: "When the snow went away -- in a rush, just as
it came -- it left behind the lawn, the garden, the pastures, the
barnyard. It also left behind locust pods, fallen branches, last
fall's leaves, snowplow scrapings, mire and muck -- the debris of
a disordered season. The snow's erasure has itself been erased.
Everything is matted to the earth or anchored in the mud except
the ridges an eastern mole has made while tunneling round and
round. "
Tangible Complexity, Letter
I Interest and awareness in issues of complexity and
chaos is increasing rapidly. Recently the popular press has been
reaching large audiences with books like "The
Tipping Point" From an research point of view many of these
books have not achieved academic depth and consequently will not
make it into the list of references of academic papers. On the
other hand, the Amazon.com sales rank (currently 16!) of "The
Tipping Point" suggest that there is a strong interest of the
general public in issues of complexity. At the same time
interactive simulation games such as SimCity and more recently the
Sims (see previous announcement) have been huge sales successes.
In more than one way these books and software titles have made
the issue of complexity a more tangible one. We are all surrounded
by complexity but now, through the playful interaction with
agent-based simulations, complexity becomes a more tangible
concept. Even through the limited sense of interacting with
artificial worlds we can experience the intricate relationships
between causes and effects in complex worlds in ways impossible
without computers.
One step further, making complex systems even more tangible, is
to build end-user oriented simulation authoring tools allowing
people to build their own agents from the ground up. One such tool
is AgentSheets.
AgentSheets allows a wide variety of users ranging from elementary
school kid to scientists to build their own interactive
simulations. End-user programming requires new programming
paradigms. AgentSheets employs a means of programming called
Tactile Programming. The behavior of individual agents is defined
by user defined rules. Conditions let agents react to mouse and
key events, check attributes and even let agents read web pages in
real time. Actions allow agents to animate themselves, move around
in a simulation world, play MIDI music, play sounds, speak, open
web pages, and compute equations. Pressing a single button
finished simulations can be turned into interactive web pages
based on Java applets. Simulations can also be exported as
JavaBean components connectable to other JavaBeans
To make complexity even more tangible and enable a social
understanding of complexity it is necessary to allow users to
exchange computational artifacts easily. Through the Behavior
Exchange AgentSheets users can upload and download agents. For
instance elementary school kids have explored Ecoworlds as complex
systems by designing their own animals, exchanging them with other
kids and testing the sustainability of the aggregate system. How
tangible are these complex systems for the kids? Using language
such as "I will eat the bird" the kids commonly blur the
distinction between their creations and themselves. In effect they
project themselves into the artificial computer world and, in so
doing, experience complex systems from within.
Research papers on AgentSheets and how it is used can be found
here.
From Neural Nets to Agricultural Soils, Announcement
"Applied Complexity" is the fifth of a series of
conferences on Complex Systems in Australasia and the first in New
Zealand expanding the international tradition of these conferences
and expecting a wide participation from around the world.
This conference will bring together the abstract with the
realistic and show advances in complex system theory and modeling
which have been applied to real world situations.
Areas of interest: mathematics, computing, modelling, physics,
chemistry, chaos, information theory, artificial intelligence,
self-organizing systems, climatology, agriculture, biology,
psychology, neural sciences, information sciences, social
sciences, anthropology, ethnobiology, economics, modeling,
conservation, and management to cite only a few at a broad level.
Papers presented must deal explicitly with issues that suggest the
extraction of broad rules of behaviour applicable across a variety
of complex systems.
