"Does anything emerge?"
A review on the state of the art in the understanding, modeling and formal description of emergence

Project Description. Despite the fervour of activities in CSS around the world, the scientific community is still unable to define when a system is complex. In an attempt to provide a working definition of CSS, 'emergence' is often chosen as the most distinguishing feature of a complex system. This may be a circular definition, since the concept of 'emergence' itself is undefined. Also, a number of established researchers question whether emergence actually exists and/or whether the concept is needed at all in the description of Nature. We saw the need to review the state of the art in the understanding, defining, modelling and formal description of emergence. This was motivated by the publication of new approaches and new mathematical tools within the physics and maths community and renewed interest in this subject in biology, ecology and philosophy.

Project Style. Our approach has been very old-fashion, surely heretical for contemporary trends. We simply aimed to learn about the subject, with no specific outcome in mind. Because of the inherently interdisciplinary nature of the subject, we did so by fostering communications between physicists, mathematicians, biologists, information theorists, sociologists, ecologists and engineers. We involved several CSIRO researchers, a few DSTO colleagues and two international invited guests: Daniel Polani and Cosma Shalizi. Amazingly, we discovered that this totally disorganised approach works: we learned, we communicated, we involved more people along the way, we are completing 9 papers, which include some original results, and we expect new projects will come out as a result.

Project Stages

• We have produced a preliminary document, containing the material we collected in our initial literature review. This is a particularly disorganised collections of references and relevant ideas, whose main purpose was to get things going.
• We completed a first review which addresses issues related to definition and detection of Emergence in sensor and communication networks. The short paper was presented at the KES conference (Knowledge-Based & Intelligent Information & Engineering Systems, Melbourne Sept 2005).
• We run a first workshop, with two international invited speakers, in Canberra 12-14 May 2005. Notice that a similar workshop (unrelated to ours) was held almost at the same time by the "The Pacific Institute of Theoretical Physics (PITP)", also in May 2005, in Vancouver, Canada.
• A second workshop was organised on 18-20 October in Canberra, to better focus the writing of the papers following the discussion which happened after the first workshop.

Project Outcomes:

We soon realised that our views and interests differed. So we decided to let the team members organise spontaneously and follow the research directions they felt more relevant. Roughly, we focussed on the following problems:

• relation between emergence, self-organisation and complexity
• relation between emergence and formal logic / computation / modelling
• the role of scale and scope in emergence study

Papers:

• Prokopenko M, Boschetti F, Ryan A, An Information-Theoretic Primer On Complexity, Self-Organisation And Emergence, Advances in Complex Systems, submitted.
• Boschetti F, Gray R, Emergence and Computability, Emergence: Complexity and Organization, accepted.
• Boschetti F, Gray R, A Turing test for Emergence, in M. Prokopenko (ed.), Advances in Applied Self-organizing Systems, Springer-Verlag, London, UK, 2007 , in print.
• Boschetti F, Gray R, McDonald D, Complexity of a modelling exercise: a critique of the role of computer simulation in Complex System Science, in preparation.
• Boschetti F, The Geometry of Novelty and Diversity, submitted to Biosystems; Special issue on Selection, Self-Organization and Diversity.
• Ryan Alex, Emergence is coupled to scope, not level, Nonlinear Sciences, abstract, nlin.AO/0609011
• Halley J, Winkler D, Classification of emergence and its relation to self-organization, Complexity, accepted.
• Lavoue F, Boschetti F, Ryan A, Grosogono A, A framework for studying the increase of complexity of interacting finite state machines, under internal review.
• Boschetti F, Prokopenko M, Macreadie I, Grisogono A. Defining and detecting emergence in complex networks, Conference paper, In R. Khosla, R. J. Howlett, and L. C. Jain, editors, Knowledge-Based Intelligent Information and Engineering Systems, 9th International Conference, KES 2005, Melbourne, Australia, September 14-16, 2005, Proceedings, Part IV, volume 3684 of Lecture Notes in Computer Science, pages 573-580, 2005.