Parece que a idéia de Geoffrey A. Landis para resolver o Paradoxo de Fermi vai ser conhecida como solução de Percolação. Branislav Vukotic e Milan M. Cirkovik implementaram recentemente um modelo de automata celulares para descrever o processo de colonização galática. Uma das conclusões foi a de que a hipótese de colonização percolativa é consistente com o modelo. Ou seja, não é uma prova que a idéia esteja correta, mas sim que é uma idéia viável e não foi refutada pelas simulações. Nas palavras dos autores:
The porosity of large = 3 clusters in our simulations (Fig. 6), coupled with low V/V0 (Fig. 11), demonstrates how this still seems acceptable within the ”Copernican” framework, thus essentially confirming the conclusions of Landis (1998) and Kinouchi (2001), but with addition of catastrophic reset events.
Search for extraterrestrial life and intelligence constitutes one of the major endeavors in science, but has yet been quantitatively modeled only rarely and in a cursory and superficial fashion. We argue that probabilistic cellular automata (PCA) represent the best quantitative framework for modeling astrobiological history of the Milky Way and its Galactic Habitable Zone. The relevant astrobiological parameters are to be modeled as the elements of the input probability matrix for the PCA kernel. With the underlying simplicity of the cellular automata constructs, this approach enables a quick analysis of large and ambiguous input parameters’ space. We perform a simple clustering analysis of typical astrobiological histories and discuss the relevant boundary conditions of practical importance for planning and guiding actual empirical astrobiological and SETI projects. In addition to showing how the present framework is adaptable to more complex situations and updated observational databases from current and near-future space missions, we demonstrate how numerical results could offer a cautious rationale for continuation of practical SETI searches.
|Comments:||Added minor language corrections, 37 pages, 11 figures, 2 tables; “Origins of Life and Evolution of Biospheres,” accepted for publication|
|Subjects:||Instrumentation and Methods for Astrophysics (astro-ph.IM); Cellular Automata and Lattice Gases (nlin.CG); Computational Physics (physics.comp-ph)|
|Cite as:||arXiv:1206.3467v2 [astro-ph.IM]|
Persistence phenomena in colonization processes could explain the negative results of SETI search preserving the possibility of a galactic civilization. However, persistence phenomena also indicates that search of technological civilizations in stars in the neighbourhood of Sun is a misdirected SETI strategy. This last conclusion is also suggested by a weaker form of the Fermi paradox. A simple model of a branching colonization which includes emergence, decay and branching of civilizations is proposed. The model could also be used in the context of ant nests diffusion.
|Comments:||2 pages, no figures, v2 with corrected definition of branching ratio|
|Subjects:||Disordered Systems and Neural Networks (cond-mat.dis-nn); Statistical Mechanics (cond-mat.stat-mech)|
|Cite as:||arXiv:cond-mat/0112137v1 [cond-mat.dis-nn]|