Byl's loop
{{Short description|Cellular automaton}}
The Byl's loop is an artificial lifeform similar in concept to Langton's loop. It is a two-dimensional, 5-neighbor cellular automaton with 7 states per cell, and was developed in 1989 by John Byl, from the Department of Mathematical Sciences of Trinity Western University.
Details
The Byl's loop was developed just a few years after Langton's simplification of Codd's automaton, which produced a simpler automaton that would reproduce itself in 151 time-steps. John Byl simplified Langton's automaton further, with an even smaller automaton that reproduced in just 25 time-steps. Byl's automaton consisted of an array of 12 chips — of which 4 or 5 could be counted as the instruction tape — and 43 transition rules, while Langton's device consisted of some 10×15 chips, including an instruction tape of 33 chips, plus some 190 transition rules.
Essentially, the simplification consisted in using fewer cellular states (7 as compared with Langton's 8) and a smaller replicating loop (12 cells as compared with Langton's 86).
{{quotation|In 1989, John Byl devised a self-reproducing automata so small, twelve cells in seven states with forty-three transition rules, that it undermines "von Neumann's 'complexity threshold' separating trivial from non-trivial self-replication" (Sigmund 1993:24{{cite book
|title = Games of Life: Explorations in Ecology, Evolution and Behaviour
|author = Karl Sigmund
|author-link = Karl Sigmund
|url = https://books.google.com/books?id=qVwIAAAACAAJ
|year = 1995
|page = 24
|publisher = Penguin
|isbn = 0-14-024209-0
}}).|[http://www.sciencetimeline.net/1961.htm ScienceTimeLine.net (1961-2003)]}}
See also
References
{{Reflist}}
Further reading
- {{citation
|author = John Byl
|title = Self-Reproduction in Small Cellular Automata
|url = https://books.google.com/books?id=UIsrNAAACAAJ
|journal = Physica D
|volume = 34
|pages = 295–299
|year = 1989
|issue = 1–2
|doi = 10.1016/0167-2789(89)90242-X
|bibcode = 1989PhyD...34..295B
}}
- {{citation
|author = John Byl
|title = On Cellular Automata and the Origin of Life
|url = http://www.asa3.org/ASA/PSCF/1989/PSCF3-89Byl.html
|journal = Perspectives on Science and Christian Faith
|publisher = American Scientific Affiliation
|volume = 41
|issue = 1
|pages = 26–29
|date=March 1989
}}
External links
- [https://web.archive.org/web/20070208184227/http://necsi.org/postdocs/sayama/sdsr/java/ visual representation] of the Byl's loop in a Java applet
- [http://cafaq.com/apps/index.php Cellular Automata FAQ - Applications] (section "What are Byl's rules for a self reproducing CA?") for the full rule set of Byl's loop
- {{citation
|url = http://lslwww.epfl.ch/pages/embryonics/thesis/Chapter3.html
|chapter = Chapter 3: Self-Replication
|author = Gianluca Tempesti
|title = A Self-Repairing Multiplexer-Based FPGA Inspired by Biological Processes
|year=1998
}}