Difference between revisions of "Eater 2"

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{{Stilllife|type=eater|name=Eater 2|pname=eater2|c=19|bx=7|by=7|discoverer=David Buckingham|life105=true|life106=true|plaintext=true|rle=true|synthesis=9|synthesisRLE=true|rulemin=B/S23|rulemax=B378/S012345678|rulespecial=[[Conway's Game of Life|Conway Life]]}}
{{Stilllife
'''Eater 2''' is an [[eater]] that was found by [[:Category:Patterns found by David Buckingham|David Buckingham]] in the 1970s. Mostly it works like the standard eater (see [[eater 1]]) but with two slight differences that make it useful despite its size; it takes longer to recover from each bite and it acts like an eater in two directions. The first property means that, among other things, it can eat a [[glider]] in a position that would destroy an eater 1. This novel glider-eating action is occasionally of use in itself, and combined with the symmetry means that an eater 2 can eat gliders along four different paths.
|name             = Eater 2
|pname           = eater2
|type2            = eater
|c               = 19
|bx               = 7
|by               = 7
|fc              = 36.0
|discoverer       = David Buckingham
|rulemin         = B/S23
|rulemax         = B378/S012345678
|rulespecial     = [[Conway's Game of Life|Conway Life]]
|isorulemin      = B/S2-in3ar
|isorulemax      = B2ikn34-aci5-ay6-i78/S012345678
|synthesis        = 6
|synthesisRLE    = true
|plaintext        = true
|rle              = true
|apgcode          = xs19_4aar0rbzx121
|niemiecid        = 19.11763
|pentadecathlonid = 19.3478
}}
'''Eater 2''' (or '''block on hat siamese hat''') is an [[eater]] that was found by [[David Buckingham]] in the 1970s. Mostly it works like the standard eater (see [[eater 1]]) but with two slight differences that make it useful despite its size; it takes longer to recover from each bite and it acts like an eater in two directions. The first property means that, among other things, it can eat a [[glider]] in a position that would destroy an eater 1. This novel glider-eating action is occasionally of use in itself, and combined with the symmetry means that an eater 2 can eat gliders along four different paths.


An eater 2 variant noticed by [[:Category:Patterns found by Stephen Silver|Stephen Silver]] in May [[:Category:Patterns found in 1998|1998]] that is useful for obtaining smaller bounding boxes is shown below. Note that eater 2 is a [[strict still life]] because the outside cells are not stable without the [[block]], but the eater 2 variant below is a [[pseudo still life]] because it is made up of an [[aircraft carrier]], [[block]] and [[hat]], each of which are stable.
An eater 2 variant noticed by [[Stephen Silver]] in May {{year|1998}} that is useful for obtaining smaller bounding boxes is shown below. Note that the canonical version of eater 2 is a [[strict still life]] because the outside 15-cell component is not stable without the [[block]] (it is, rather, an [[inductee]]), but the eater 2 variant below is a [[pseudo still life]] because it is made up of an [[aircraft carrier]], [[block]] and [[hat]], each of which are stable.


Eater 2 can also be used to eat objects other than gliders. For example, one of them can eat a [[Lightweight spaceship|lightweight]] or [[Middleweight spaceship|middleweight]] spaceship, two of them can eat a [[60P5H2V0]], three of them can eat the bulk of a [[3-engine Cordership]], and seven of them can be arranged to eat the majority of the [[7-in-a-row Cordership]].
Eater 2 can also be used to eat objects other than gliders. For example, one of them can eat a [[Lightweight spaceship|lightweight]] or [[Middleweight spaceship|middleweight]] spaceship, two of them can eat a [[60P5H2V0]], two or three of them can eat the bulk of a [[2-engine Cordership|2-engine]] or [[3-engine Cordership]] respectively, and seven of them can be arranged to eat the majority of the [[7-in-a-row Cordership]].


On January 29, [[:Category:patterns found in 2004|2004]] [[Mark Niemiec]] found a [[:Category:patterns that can be constructed with 9 gliders|9]]-[[glider]] [[glider synthesis|synthesis]] of a variation of eater 2 that consists of a hat, a block, and a [[table]].
The eater 2 is made up of 2 [[siamese]] hats supported by a block. Variants involving siamese [[loop]]s and [[eleven loop]]s also function.
 
It serves as the logo of [[Catagolue]].
 
==Synthesis==
On January 29, {{year|2004}} [[Mark Niemiec]] found a {{gliders|9}} [[synthesis]] of a variation of eater 2 that consists of a hat, a block, and a [[table]]. On October 9th, 2014, David S. Miller found a natural eater 2 in a soup from [[Adam P. Goucher]]'s apgsearch script<ref name="post13749" />, from which Tanner Jacobi derived a 6-glider synthesis.<ref name="post14192" />


==Image gallery==
==Image gallery==
Line 15: Line 41:


==See also==
==See also==
*[[65P13.1]]
*[[Eater 3]]
*[[Eater 3]]
*[[Eater 4]]
*[[Eater 4]]
*[[Eater 5]]
*[[Eater 5]]
*[[Gliderless gun 1]]
*[[Period-44 MWSS gun]] where an eater 2 variant facilitates the evolution of MWSSes.
*[[Buckingham's p13]]
 
==References==
<references>
<ref name="post13749">{{LinkForumThread
|format = ref
|title  = Re: apgsearch: a high-performance soup searcher
|p      = 13749
|author = David S. Miller
|date  = October 10, 2014
}}</ref>
<ref name="post14192">{{LinkForumThread
|format = ref
|title  = Re: Soup search results
|p      = 14192
|author = Tanner Jacobi
|date  = November 8, 2014
}}</ref>
</references>


==External links==
==External links==
{{LinkWeisstein|Eater2.html}}
{{LinkWeisstein|Eater2.html}}
{{LinkLexicon|lex_e.htm#eater2}}
{{LinkLexicon|lex_e.htm#eater2}}
[[Category:Strict still lifes]][[Category:Strict still lifes with 19 cells]]
{{LinkCatagolue|xs19_4aar0rbzx121}}
{{LinkNiemiec|bits-19.htm|patternname=Nineteen-Bit Life Objects}}
 
{{Symmetry|diagonal2}}

Revision as of 02:37, 1 February 2020

Eater 2
x = 7, y = 7, rule = B3/S23 3bob2o$b3ob2o$o$b3ob2o$3bobo$3bobo$4bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ THUMBSIZE 3 ZOOM 21 HEIGHT 400 SUPPRESS ]]
Pattern type Strict still life
Eater
Number of cells 19
Bounding box 7 × 7
Frequency class 36.0
Discovered by David Buckingham
Year of discovery Unknown

Eater 2 (or block on hat siamese hat) is an eater that was found by David Buckingham in the 1970s. Mostly it works like the standard eater (see eater 1) but with two slight differences that make it useful despite its size; it takes longer to recover from each bite and it acts like an eater in two directions. The first property means that, among other things, it can eat a glider in a position that would destroy an eater 1. This novel glider-eating action is occasionally of use in itself, and combined with the symmetry means that an eater 2 can eat gliders along four different paths.

An eater 2 variant noticed by Stephen Silver in May 1998 that is useful for obtaining smaller bounding boxes is shown below. Note that the canonical version of eater 2 is a strict still life because the outside 15-cell component is not stable without the block (it is, rather, an inductee), but the eater 2 variant below is a pseudo still life because it is made up of an aircraft carrier, block and hat, each of which are stable.

Eater 2 can also be used to eat objects other than gliders. For example, one of them can eat a lightweight or middleweight spaceship, two of them can eat a 60P5H2V0, two or three of them can eat the bulk of a 2-engine or 3-engine Cordership respectively, and seven of them can be arranged to eat the majority of the 7-in-a-row Cordership.

The eater 2 is made up of 2 siamese hats supported by a block. Variants involving siamese loops and eleven loops also function.

It serves as the logo of Catagolue.

Synthesis

On January 29, 2004 Mark Niemiec found a 9-glider synthesis of a variation of eater 2 that consists of a hat, a block, and a table. On October 9th, 2014, David S. Miller found a natural eater 2 in a soup from Adam P. Goucher's apgsearch script[1], from which Tanner Jacobi derived a 6-glider synthesis.[2]

Image gallery

Eater 2 variant

See also

References

  1. David S. Miller (October 10, 2014). Re: apgsearch: a high-performance soup searcher (discussion thread) at the ConwayLife.com forums
  2. Tanner Jacobi (November 8, 2014). Re: Soup search results (discussion thread) at the ConwayLife.com forums

External links

Template:LinkWeisstein