A long-term goal of this project is to give new impulses for the field of Artificial Life by the present software tool alien specially designed to conduct computer experiments with programmable matter in a physically realistic environment. It should be stressed here that alien is not a simulator for Molecular Dynamics.

In the following some particular aspects are highlighted where we hope that advances will be made. Beside that, this software tool can also be seen as some kind of game where one can play, experiment and explore own worlds without any specific aims.

We strive for simulating life on a digital and non-carbon basis. This aim is based on the assumption that it is not crucial for living structure to be composed of physical entities of the real-world. alien utilizes a physics engine where the interacting entities can be programmed and execute tasks. It allows to create complex structures which can act in their environment in a purposeful manner.

A goal in this respect is to construct artificial universes that exhibit self-organizing and self-repairing structures maintaining a higher degree of order in comparison to their environment. More precisely, we seek for machines which

  • control their movement,
  • search for nutrients,
  • interact with their vicinity,
  • replicate if enough resources are available,
  • repair damage on their own,
  • and possibly show intelligent behavior.

It is still an unsolved question how complex system which we would consider as life can emerge from ancestry structures of less complexity. One possibility is that some kind of prebiotic evolution without RNA and DNA comes into play. In this spirit the emergence of life can be considered as a gradual process and not as a spontaneous miracle.

One of our objectives is to construct an environment where such conditions are simulated.

It is unknown how highly-organized systems such as biological cells are assembled from component which follow simple rules. From theoretical point of view, at least two types of self-replicating machines are conceivable: replication by self-inspection as well as replication by using some information storage such as DNA. While the first one requires intricated self-analyzing techniques and suffers some fundamental limitations (difficult for large structures and vulmerability to errors), the second one paves the way to open-ended evolution.

A goal here is to create machines which use (variants of) these replication techniques in order to get an impression of how life can be.

It has become a well-known fact that evolution driven by natural selection is the crucial force causative for the complexity and diversity of our ecosystem reaching from relatively simple prokaryotes such as bacteria to most involved multicellular organisms.

By designing machines that can preserve their information by some digital correspondent to DNA one can make evolutionary studies in an entirely simulated environment. A particularity of alien in comparison to many other simulators for evolution processes is that the entire environment consists of the same type of entities as the individuals/machines. Merely the composition and state of the entities determines the life-like behavior.

Evolution by natural selection and mutation seems to be the cornerstone of increasing complexity. Once a complete digital ecosystem containing replicating machines has been obtained long time studies can be made. The effect of mutation rates, environmental noises, gene transfer, evolutionary arms races and symbiosys are aimed to be investigated.

Further questions about stability of such systems in comparison to certain parameters can be tackled.