View source for Queen bee shuttle

{{Oscillator
|name             = Queen bee shuttle
|pname            = transqueenbeeshuttle
|family           = Queen bee shuttle
|f1               = Shuttle
|c                = 20
|bx               = 22
|by               = 7
|fc               = 28.4
|p                = 30
|m                = 15
|h                = 17.9
|v                = 0.96
|sv               = 0.96
|discoverer       = Bill Gosper
|discoverer2      = Robert W. April
|discoverer3      = Richard P. Howell
|discoveryear     = 1970
|rulemin          = B3/S23
|rulemax          = B38/S238
|rulespecial      = [[Conway's Game of Life|Conway Life]]
|isorulemin       = B3-k/S23-kr
|isorulemax       = B2n34ceqyz5jkq6-in7c8/S234cekz5ekr6-ac7c8
|synthesis        = 6
|synthesisRLE     = true
|plaintext        = true
|rle              = true
|apgcode          = xp30_w33z8kqrqk8zzzx33
|pentadecathlonid = 20P30.2
|viewerconfig     = #C [[ HEIGHT 500 THUMBSIZE 3 ZOOM 21 GPS 10 ]]
}}{{stub}}
The '''queen bee shuttle''' (or '''basic shuttle'''<ref>{{CiteLexicon|file=lex_b.htm#basicshuttle|name=Basic shuttle|accessdate=June 11, 2009}}</ref>) can refer to one of two very closely related {{period|30}} [[shuttle]] [[oscillator]]s in which a [[queen bee]] travels back and forth between two [[block]]s (see [[#Isomers|Isomers]]). It was found by [[Bill Gosper]] in {{year|1970}}<ref>{{CiteHickersonOscillators|accessdate=March 14, 2020}}</ref> and was the first period-30 oscillator to be found. In terms of its minimum population of {{cells|20}} [[cell]]s, it is the smallest known oscillator with period greater than 15.<ref>{{cite web|url=https://web.archive.org/web/20220520073223/http://www.pentadecathlon.com/objects/class2/class2.php?part=1 |title=Class 2 Objects Catalog - Oscillators |accessdate=April 8, 2009}}</ref>

The queen bee shuttle is the basis of [[Gosper glider gun]], the first known and most compact gun in Game of Life. 

== Isomers ==
There are two possible [[isomer]]s for the queen bee shuttle; the version shown in the infobox to the right being the "[[trans]]"-version.

<gallery widths=128px style="text-align:center;">
File:cisqueenbeeshuttle.png|Cis-queen bee shuttle
File:transqueenbeeshuttle.png|Trans-queen bee shuttle
</gallery>

===Cis-queen bee shuttle===

{{EmbedViewer
|pname        = cisqueenbeeshuttle
|viewerconfig = #C [[ THUMBSIZE 2 ZOOM 12 GPS 10 AUTOSTART ]]
|position     = center
|caption      = Cis-queen bee shuttle; blocks are "on the same side" ([[kinetic symmetry]] n-e)
|style        = width:300px;
|apgcode      = xp30_w33z8kqrqk8zzzw33
}}

===Trans-queen bee shuttle===

{{EmbedViewer
|pname        = transqueenbeeshuttle
|viewerconfig = #C [[ THUMBSIZE 2 ZOOM 12 GPS 10 AUTOSTART ]]
|position     = center
|caption      = Trans-queen bee shuttle; blocks are "on different sides" ([[kinetic symmetry]] n.e)
|style        = width:300px;
|apgcode      = xp30_w33z8kqrqk8zzzx33
}}

== Glider synthesis ==
There are a few 4-glider components that turn any one-sided stabilization of the queen bee, such as a block, into a queen bee shuttle variant, yielding 6-glider [[Glider synthesis|syntheses]] for both common variants. The synthesis of the cis-queen bee shuttle was later reduced to 5 gliders in July 2020,<ref name="post100652" /> and an alternate 6-glider synthesis of the trans-queen bee shuttle has also been found.<ref name="post147138" />
An alternate 5-glider synthesis of the cis-queen bee shuttle was found in March 2023.<ref name="post159582" /><ref name="j4000837544" />

{{EmbedViewer
|pname        = block2queenbeeshuttle
|viewerconfig = #C [[ ZOOM 4 WIDTH 600 HEIGHT 600 ]]
|position     = center
|caption      = A collection of nine such 4-glider components mentioned above, turning a block into a queen bee shuttle
|style        = width:300px;
}}

== Variations ==
The shuttles were originally stabilized against one another in a square of eight shuttles, but many other stabilisations of the queen bee are now known, such as [[buckaroo]] (which utilises an [[eater 1]]), [[hectic]] (which relies on [[glider]]s) and {{LinkCatagolue|code=xp30_wmm0e93z643xgk333kgzc4ozwdd0eio|style=raw|patternname=a thin one}} (allowing a 20-cell wide footprint with an unnamed still life) and {{LinkCatagolue|code=xp30_wssx3us8zwgogw31z2566652zy725brb52zxooy4oo|style=raw|patternname=the thinnest known one}} (allowing a 18-cell-wide (albeit 25-cell-tall) one using other queen bees), the latter two of which are useful in bounding box reductions.

The '''queen bee loop''' (or '''ouroboros bees'''), another form of the queen bee shuttle that was found in 1970 (also by Bill Gosper), is a closed loop made of four queen bees that clean up each other's [[beehive]]s. It was forgotten about in many sources and independently rediscovered in {{year|2008}} by [[Nicolay Beluchenko]].<ref>{{LinkGoLNews|2008/11/new_small_period_oscillators_2.html|title=New Small Period Oscillators|date=November 23, 2008|author=Heinrich Koenig}}</ref> It is also possible to create a partial loop oscillator consisting of two or three queen bees by removing one or two of the queen bees in the loop and placing two stabilizing blocks appropriately.

{| style="margin-left:auto;margin-right:auto;" |
|-
|{{EmbedViewer
|pname = queenbeeloop
|position     = center
|viewerconfig = #C [[ THUMBSIZE 2 ZOOM 12 ]]
|caption      = A queen bee loop
|style = width:360px;
}}
|{{EmbedViewer
|pname = partialqueenbeeloop
|position     = center
|viewerconfig = #C [[ THUMBSIZE 2 ZOOM 12 ]]
|caption      = A partial queen bee loop with only three queen bees
|style = width:360px;
}}
|}

== Occurrence ==
{{related|List of common oscillators}}
The cis-queen bee shuttle and the trans-queen bee shuttle are the 18th and 19th most [[common]] naturally-occurring oscillators in [[Achim Flammenkamp's census]].<ref>{{citeAchim|accessdate=January 15, 2009}}</ref> On [[Catagolue]], it is the most common period 30 oscillator, with all other natural oscillators of that period featuring it in some form.<ref>{{citeCatagolueStats|October 27, 2018}}</ref>

The trans version is about 2% more common than the cis version on Catagolue.

== Gallery ==
{|style="margin:auto;width:300px;"
|{{EmbedViewer
|pname        = queenbeeshuttlepredecessor
|position     = center
|viewerconfig = #C [[ THUMBSIZE 2 ]]
|caption      = Queen bee shuttle [[dimer]] predecessor made up of a [[pi-heptomino]], two [[blinker]]s and two blocks. Found by Gosper in April {{year|1992}}.
}}
|-
|{{EmbedViewer
|pname        = p26queenbeeshuttle
|position     = center
|viewerconfig = #C [[ GPS 13 THUMBSIZE 2 ]]
|caption      = A period-26 version of the queen bee shuttle, found by [[James Pascua]] based on a partial by [[Entity Valkyrie]]<ref name="post122080" />
}}
|-
|{{EmbedViewer
|pname    = queenbeeshuttlesrephasingblinker
|position = center
|caption  = The shuttle produces a spark at the blocks that can be used to [[Phase_shift|rephase]] a [[blinker]]; two must be used to make a functioning oscillator from this reaction to prevent formation of a deadly traffic light.
}}
|}

== References ==
<references>
<ref name="j4000837544">{{CiteCatagolueJob|job=4000837544|date=March 25, 2023}}</ref>
<ref name="post100652">{{LinkForumThread
|format = ref
|title  = Re: Randomly enumerating glider syntheses
|p      = 100652
|author = Ian07
|date   = July 18, 2020
}}</ref>
<ref name="post122080">{{LinkForumThread
|format = ref
|title  = Re: Oscillator Discussion Thread
|p      = 122080
|author = James Pascua
|date   = February 8, 2021
}}</ref>
<ref name="post147138">{{LinkForumThread
|format = ref
|title  = Re: Synthesising Oscillators
|p      = 147138
|author = Carson Cheng
|date   = June 15, 2022
}}</ref>
<ref name="post159582">{{LinkForumThread
|format = ref
|p      = 159582
|title  = Re: Synthesising Oscillators
|author = Carson Cheng
|date   = March 25, 2023
}}</ref>
</references>

== External links ==
* {{LinkLexicon|lex_q.htm#queenbeeshuttle}}
* {{LinkCatagolue|xp30_y68sul3zggxggy1123z127e721y6oke7ekozy5ckogzy5ca731|patternname=Queen bee loop}}
* {{LinkPentadecathlonObject|20P30.1}}
* {{LinkPentadecathlonObject|20P30.2}}

{{Symmetry|osc=turn180}}
{{Sparker|p=30|type=dot|strength=strong}}