Information Technology Reference
In-Depth Information
Emergence of Self-Replicating Loops in an
Interactive, Hardware-Implemented
Game-of-Life Environment
Andre Stauffer
1
and Moshe Sipper
1
,
2
1
Logic Systems Laboratory,
Swiss Federal Institute of Technology in Lausanne,
CH-1015 Lausanne, Switzerland.
andre.stauffer@epfl.ch
2
Department of Computer Science,
Ben-Gurion University, Beer-Sheva 84105, Israel,
sipper@cs.bgu.ac.il
Abstract.
We present the design of an interactive self-replicating loop,
wherein the user can physically induce the loop's creation and then con-
trol its replication and destruction. After introducing the
BioWall
,a
reconfigurable electronic wall for bio-inspired applications, we describe
the design of our novel loop and delineate its hardware implementation
in the wall.
1 Introduction: Cellular Automata and Self-Replication
The study of self-replicating machines, initiated by von Neumann over fifty years
ago, has produced a plethora of results over the years [1,2]. Much of this work is
motivated by the desire to understand the fundamental information-processing
principles and algorithms involved in self-replication, independent of their phys-
ical realization [3,4]. The fabrication of artificial self-replicating machines could
have diverse applications, ranging from nanotechnology [5], through space ex-
ploration [6], to reconfigurable computing tissues—the latter of which shall be
introduced in Section 2.
A major milestone in the history of artificial self-replication is Langton's
design of the first self-replicating loop [7]. His 86-cell loop is embedded in a
two-dimensional, 8-state, 5-neighbor cellular space; one of the eight states is
used for so-called core cells and another state is used to implement a sheath
surrounding the replicating structure. Byl [8] proposed a simplified version of
Langton's loop, followed by Reggia
et al.
[4] who designed yet simpler loops, the
smallest being sheath-less and comprising five cells. More recently, Sayama [9]
designed a structurally dissolvable loop, based on Langton's work, which can
dissolve its own structure, as well as replicate.
All self-replicating loops presented to date are essentially worlds unto them-
selves: once the initial loop configuration is embedded within the cellular au-
tomaton (CA) universe (at time-step 0), no further user interaction occurs, and
the CA chugs along in total oblivion of the observing user.
