IceNine: Difference between revisions

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m The link for the fictional chemical was pointing to the page of the real chemical
Blanking on how to add a reference, but it should be https://conwaylife.com/forums/viewtopic.php?p=136948#p136948
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{{Cquote|The IceNine I tried to describe doesn't have a memory per se, any more than a cell's DNA knows the position of every lipid molecule in its cell wall.  It's an active, growing agar with lots of edge sparks that just happen to annihilate nearby gliders and still lifes unusually efficiently.  Along with several other utterly improbable properties. Basically it's the spacefiller that wins the Survival of the Fittest Award in an infinite Life universe, and it's about as likely as the proverbial tornado in a junkyard building a jumbo jet.}}
{{Cquote|The IceNine I tried to describe doesn't have a memory per se, any more than a cell's DNA knows the position of every lipid molecule in its cell wall.  It's an active, growing agar with lots of edge sparks that just happen to annihilate nearby gliders and still lifes unusually efficiently.  Along with several other utterly improbable properties. Basically it's the spacefiller that wins the Survival of the Fittest Award in an infinite Life universe, and it's about as likely as the proverbial tornado in a junkyard building a jumbo jet.}}


It is generally agreed that a pattern exhibiting the characteristics of IceNine cannot exist in [[Conway's Game of Life]], but a formal proof remains elusive.
It is generally agreed that a pattern exhibiting the characteristics of IceNine cannot exist in [[Conway's Game of Life]], but a formal proof remains elusive. However, mechanisms that a replicator could implement to remove enough nearby ash to make space for future copies have been proposed and and have been proven  to function on small scales.  


==Notes==
==Notes==

Revision as of 03:39, 18 March 2022

IceNine[note 1] is Dave Greene's name for a hypothetical unstoppable quadratic growth pattern that expands outward through random ash at speed c/137, described as follows in a tongue-in-cheek post in February 2008:

He went on to further characterize IceNine as follows:

It is generally agreed that a pattern exhibiting the characteristics of IceNine cannot exist in Conway's Game of Life, but a formal proof remains elusive. However, mechanisms that a replicator could implement to remove enough nearby ash to make space for future copies have been proposed and and have been proven to function on small scales.

Notes

  1. ↑ The name is a reference to the chemical of the same name in the novel Cat's Cradle by Kurt Vonnegut, with similar properties to the hypothetical pattern. It is not related to Ice IX, a metastable form of solid water.
  • Adam P. Goucher (June 13, 2009). Re: Stable Life? (discussion thread) at the ConwayLife.com forums