Reviews

Digital Digital Burgess Conference Follow-up:
Stuart Gold
Conference was held August 29-September 1 1997, Banff Alberta, Canada
.

Stuart Gold's Reviews of presentations by
Przemyslaw Prusinkiewicz, Steve Grand and Bruce Damer

Przemyslaw Prusinkiewicz
Modelling, Simulation, and Visualization of Living & Extinct Plants

Przemyslaw Prusinkiewicz demonstrated L-Systems which used notation as a programming language to describe models. 3-d models were shown which were derived from simple rotation of 2-d models. The models closely resembled plant life in nature in the forms they took and the way they behaved. e.g. rate of growth became dependent on its position in space and may grow upwards faster than they spread.

The organisms simulated growth demonstrating growth of stems, branches, flowers and finally seeds.

Each node is determined by the parent node (i.e. lineage). However context sensitive L-Systems involve transfer of nutrients from one node to another, modeling the propagation of signals which mimics the action of flowering hormones.

In open L-Systems environmental factors are used as feedback to influence the growth of the plants at each stage. Simulations showed adaptation of plant models to competition by peer plants e.g. if plant is shaded by a neighbour then branching is curtailed or shed. Also to the presence or absence of water in the soil.


Steve Grand

Demonstrated a program developed by his company CyberLife a former computer games company now focusing on artificial life programs. Steve spent the last five years developing his ideas which have culminated in the program called Creatures which has just been released in the US.

Although Creatures is a game it is not a toy. It employs advanced neural network techniques to breathe life into small furry creatures called Norns that inhabit the fantasy world of Albia. Norns hatch from eggs and during their life cycle learn to communicate with each other and humans, and learn how to play and eat. Norns have a natural enemy called a Grendl which although simpler are genetically engineered to be incompatible with Norns. Norns eventually grow old and die but along the way they can contract diseases. Norns have a body chemistry which is a simplified model of that found in natural mammal systems.

Steve's presentation focused primarily on the question of whether his creatures were alive or not. He introduced a series of three thought experiments in order to engage the participants in this exploration.

Thought Experiment 1: The persistent phenomenon. Given that your body as a child no longer exists today (as all the particals in your body have been renewed) does the continuity of life exist only in inherited memories?

Thought Experiment 2: Imagine a scanner that could copy a human being to the finest detail inside the memory of a computer, reproducing the human's ability to think and reason . Can this copy of a human being be thought of as alive?

Thought Experiment 3: Things that persist persist, things that don't don't (Didn't get much on this one - anyone else get more?)

Steve's Conclusion:

  1. The hardware/Software boundary is a myth. There is only software.
  2. Life comprises more than one mode of persistence - Life is 'active' persistence.
  3. First order simulations are not instances of the thing they simulate. Life is an nth order phenomenon and can only arise from nth order simulations.


Bruce Damer

Bruce Damer, the conference chair began by describing his work on Nerve Garden which is a project designed to bring the experience of life processes to a wide Internet audience and demonstrate the power and utility of the Virtual Reality Modeling Language (VRML).

Bruce postulates the rising of an emergent behaviour on the Internet based around technologies such as VRML and shared collaborative worlds in the form of virtual environments. Maybe millions of ten year olds tinkering on the web will initiate an emergent evolutionary phenomenon in cyberspace equivalent to the Cambrian explosion in Darwinian evolution.

Bruce went on to describe and demonstrate on-line a virtual world on the Internet called Alpha World, that has over 200,000 citizens. Over a period of 2 years the citizens of Alpha World have 'built' thousands of virtual structures comprising over 14 million separate components. The emergent community from this world is so alive that some of its citizens got together to purchase the world and the technology from the owners after the demise of the company.

Bruce asserts that it is difficult to separate the concept of 'life' as represented by animals and plants, from the machines and artifacts created by humanity. From outside the earth all activity and processes observed on the planet surface would be seen as indicating and indeed be part of the living biosphere.

Describing life as pushing through barriers Bruce, sees spaceflight as just another barrier which we have hardly breached.

If we are a stepping stone providing a channel for what has been evolving for 8 million years to transcend this matrix and evolve in a form that fits the future environment, then the future isn't in sending our inadequately evolved bodies and minds out into space. We need perhaps another form that is better adapted to life off the planet.

Stuart A. Gold

Director
Bauer Gold Associates Ltd
sgold@bauergold.co.uk
http://www.bauergold.co.uk





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