University of Dortmund, Dempt. of Computer Science, Chair of Systemsanalysis (LS XI)

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Macroscopic and Microscopic Computation in an Artificial Chemistry

Second German Workshops on Artificial Life (GWAL'97) Dortmund 1997

### Abstract

Chemical and biochemical systems as part of living organisms
have been shown to possess interesting computational
properties. Example:
the information flow in the chemotaxis system of Escherichia Coli.
In a parallel development, the chemical computation metaphor is
becoming more and more frequently used as part of the emergent computation paradigm
in Computer Science.
In this contribution we will discuss two ways of how information
can be processed by a collection of molecules floating around in
well-stirred tank reactor.
In the first case the information is stored as a concentration
of a substances and computation is carried out by increase and decrease
of concentration levels. We will refer to this as **macroscopic computation**.
In the second case -- **microscopic computation** --
the result of a computation is represented by single
molecules. The dynamics is stochastic, in contrast to macroscopic
computation
where the dynamics can be described with ordinary differential equations.

In both cases the result emerges from many simple and parallel interactions.
In order to show the abilities of such systems we will use
**artificial chemistries** which are simulated reaction systems
of mathematical or algorithmic objects.

full paper
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