Galactic Cliques

This set of scripts seeds civilisations in a galaxy, and calculates how many civilisations can form causally connected groups. Civilisations are placed in a spatial distribution corresponding to the canonical Galactic Habitable Zone, and their arrival time as a technological civilisation is sampled from a Gaussian distribution.

This population is then tested to determine which civilisations are aware of each other at arrival, which determines the size of a group. The full details of this work were originally published as

Forgan (2017): International Journal of Astrobiology, 16, 349-554

About the code

The code is written entirely in Python 2.7, and relies on numpy 1.8.0 and matplotlib 1.3.0.

Objects and modules

civilisation.py - describes a Civilisation Object (a star system hosting a civilisation)

galaxy.py - describes a Galaxy object (a collection of Civilisations)

params.py - handles the reading in of data from parameter files (example given in input_MCR.params)

Scripts to execute

cliques_single.py - carries out a single realisation

cliques_MCR.py - carries out a set of Monte Carlo Realisations (MCRs) for one set of parameters (to compute mean/standard deviations of key values)

the other files carry out many MCR sets to carry out a parameter sweep

cliques_MCR_mu_vs_sigma_life.py cliques_MCR_vs_mu_life.py cliques_MCR_vs_nciv.py cliques_MCR_vs_sdarrive.py cliques_MCR_vs_sigma_life.py

All of the above files end by plotting their output data. If one wishes to plot and not re-run, then the plot_ scripts allow this.