“The
spider has constructed a web of statistical probability, honed to near perfection
by millions of years of evolution.” (Robert J. Hustwit) Photo by Alfonso
Diaz.
QUOTES
Roger
C. Conant & W. Ross Ashby
The living brain must proceed in learning by the formation of a model (or
models) of its environment.
John L. Casti
The Central Limit Theorem serves as a prototype for what we might call a
law of complex systems.
Emergent Universe Alliance
An innovative science outreach partnership that seeks to create public appreciation
for what is arguably the most significant scientific challenge of this
new century (www.eualliance.org,
www.emergentuniverse.org/emp/).
ARTICLES
Causality in Complex Systems
by Andreas Wagner
A regularity notion of causality can only be meaningfully defined for systems
with linear interactions among their variables. For the vastly more important
class of nonlinear systems, no such notion is likely to exist.
The
lognormal as universal descriptor of unconstrained complex systems:
a unifying theory for complexity
by Stephan Halloy and Peter Whigham
Analysis of complex systems data using the lognormal pattern as a benchmark provides
useful practical insights into system status, disturbance, successional phase,
diagnosis of thresholds and boundaries between systems, etc.
A Theoretical Framework for Abundance Distributions in Complex Systems
by Stephan R.P. Halloy
An explanation on how and where splits occur in a complex system. Then a
simple resource attraction model is proposed to study the implications
and effects of the theoretical concepts.
The
wealth of species: ecological communities, complex systems and the
legacy of Frank Preston
by Jeffrey C. Nekola and James H. Brown
Four different "distributions of wealth" (species abundance distributions,
species–area and species–time relations, and distance decay of compositional
similarity) are not unique to ecology, but have analogues in other physical,
geological, economic and cultural systems.
Universal
Diversity Patterns Across the Sciences
by Jeffrey C. Nekola
Several intensively studied ecological diversity patterns appear to have
almost exact analogues across a wide range of disciplines including physics,
economics, linguistics, sociology and the geosciences.
DISCUSSION TOPICS
Complex '09 Workshop on Causality in Complex Systems
One of the reasons people have difficulty in dealing with complex systems
is that the linear causal chain way of thinking - A causes B causes C causes
D ... etc - breaks down in the presence of feedback and multiple interactions
between causal and influence pathways. One could say that complex systems
are characterised by networked rather than linear causal relationships.
LINKS
Life is log-normal!
by Eckhard Limpert and Werner A. Stahel
The model fills
a 100 years old gap of demonstrating the ubiquity of lognormal distribution
in life. The characterization makes complicated
things easy, from science to various applications and everyday life. It's
normal, that life is log-normal or - multiplicative
normal.
Complex Open Systems Research Network
mplexity is the common frontier in the physical, biological and social sciences.
This Network will link specialists in all three sciences through five generic
conceptual and mathematical theme activities.
