cellular automata

Nils Aall Barricelli’s Bionumeric Organisms

Wednesday, September 7th, 2011

From Barticelli's 1953 experiments

Before there was Wolfram’s class 4 cellular automata, before there was Conway’s Game of Life, there was Nils Aall Barricelli and his bionumeric organisms.  The creation of ‘living’ things synthetically, of generative design, of patterns between order and chaos.

After reading this article I was surprised I hadn’t come across Barricelli before, given the influence of his work.  A mathematician excited by the recent invention of the computer, evaluating his work visually rather than with equations, excited by the possibility of creating synthetic forms within a computer, without the intention to explain nature:

 While admitting a connection back to Darwinian theory, he ultimately had no interest in merely simulating the realm of biology. his experiments were not models. rather, he wished to open up an autonomous field of life that was exclusively bionumeric. Barricelli’s numerical organisms were “alive” within a mathematical machine first and foremost. if they also revealed something about the bio- logical realm, so be it.

He drew up plans for DNA computers ten years after the discovery of the double helix:

his 1963 paper on “numerical testing of evolution theories” bears par- ticular historical significance. in it, Barricelli proposes a “chemo-analogical computer” using DNA molecules as the computational substrate—a mere ten years after the discovery of DNA by Watson and Crick. According to Barricelli’s conjectures, such a computer would consist of a normal “hardware” computer connected to a “wet- ware” environment made up of DNA molecules. Barricelli constructed a “DNA-norm” to govern the cellular phe- nomena of the base-pair interactions. Computations would first be transferred from hardware to wetware; the DNA molecules would perform the computations; and the results would be fed back into the computer.

He used the computer to explore architectures for interactions that give rise to organisms- defining rules for the evolution of numbers from row to row, based on their local context.  He looked at the printed output and changed the rules, trying to determine what caused patterns between total randomness and monotony, patterns that would give rise to things that appeared living.

HEXAGON

Thursday, April 1st, 2010

HEXAGON was a collaborative performance piece which sought to use the ideas of non-hierarchies,  interactivity, and emergence to create and perform music.

We want to create the experience a music performance as a non-hierarchy.  Performances now create the image of a DJ or Rock-god, elevated on a stage, with the focus of an entire room upon them.  We will invert this, placing the audience at the center, and surrounding them with musicians on the same level.  It will be a fluid environment, the audience is free to move around the space, and look upon the musicians as well as each other.

In designing the performance space we imagine a system where the performers respond in music to each other as well as the audience, and is for the most part fixed.  The sound spreads dependent on the location of the musician, so the experience of an audience member changes as they move through the space.  There will be no chairs to allow them to move around freely.  For these performances acoustic guitars will be used, but the future performances can potentially include voice, or local amplifiers.

The music is made inspired from the dynamics of cellular automata.  For each update there is a simple rule that determines the output given the input of the neighboring states.  To abstract this concept and apply it to the performance of multiple musicians, we create simple scripts, a concept from improvisational acting.  Scripts include playing only one one note with random rhythms, playing one note with the same rhythm, playing any note with the same rhythm, sliding upward in rhythm, etc.  In the rehearsals the performers sit in a circle facing the center, to easily see one another, and scripts are listed.  The scripts are performed once or a few times,  and reflections are written to consider what the effects are in terms of the degree to which the script promotes musician interaction, how fluid it feels, and any other emotions it brings up.   These scripts  are metaphorically equivalent to the cellular automata update rules, in that the musicians would use the other musicians as input and the rule to determine what to play.  The reflections written are a record of the emergent properties of the scripts carried out by each of the musicians.

For the first performances we will use acoustic guitars because they are portable and do not require speakers.  A composition will be made from considering the reflections from the scripts and this will be performed live.  Since the music is generative, no two performances will be the same, but all of the patterns will be fixed.

The performances were carried out in Spring 2009 at Milepost 5 and Coffee Break.

S&P CA

Thursday, December 17th, 2009

A genetic algorithm of cellular automata rules in one dimension to model the s&p 500.