Twin bees shuttle
|Twin bees shuttle|
|View animated image|
|View static image|
|Number of cells||28|
|Bounding box||32 × 13|
|Discovered by||Bill Gosper|
|Year of discovery||1971|
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The twin bees shuttle (or B-heptomino shuttle) can refer to one of four very closely related period-46 shuttle oscillators (see section "Variants") in which two B-heptominoes travel back and forth between stabilising blocks.
The twin bees shuttle was found by Bill Gosper in 1971. Before the Snark was discovered, it and its variants were the basis of all known period-46 oscillators (the version at right being the smallest based on its minimum population of 28 cells), and until the discovery of Tanner's p46, the basis of all known true period 46 guns including the second known basic gun, new gun 1. The simplest such gun is the bi-gun, in which two twin bees shuttles collide with each other head-on (much like the collision of two queen bees in the Gosper glider gun).
Variants and alternative stabilizations
There are numerous other ways to stabilize the ends other than the four detailed below.
Sides stabilised by only a single block (as can be seen in three of the above variants) result in the creation of a very large spark, referred to as the twin bees shuttle spark, which is useful in a number of ways (see #Reactions).
|Some additional ways to stabilize the twin bees shuttle; the top-left variant is used in centinal|
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The four variants are shown in the table, with the three-block variant shown in the infobox due to having the lowest minimum population:
|Cis-twin bees shuttle
Blocks are "on the same side"
|Trans-twin bees shuttle
Blocks are "on different sides"
|3-block twin bees shuttle
3 blocks are used
|4-block twin bees shuttle
4 blocks are used
The twin bees shuttle is capable of several interesting reactions, mostly due to the twin bees shuttle spark, many of which are detailed below.
The twin bees shuttle spark is capable of being partially eaten by a correctly-positioned block, yielding further possible variants of the shuttle, many of which have occurred naturally. Since the spark is odd-symmetric whereas the block is even-symmetric, there are two ways in which each block can be positioned to yield a valid oscillator.
A block is said to be in "cis" position if closer to the shuttle, such that the spark interacts with it at its farther side, and in "trans" position if farther from the shuttle, such that the spark interacts with it at its closer side.
A table of all possibilities can be found as follows:
|Base shuttle||Block count||Image||Cells||Block positions||apgcode||Synth.|
Glider conversions and reflections
|It has been suggested that this page or section be split into p46 technology. (Discuss)|
Interactions based on the twin bees shuttle are numerous and can have many applications. Some notable reactions are period 46 oscillators that can directly reflect gliders, lightweight spaceships, and middleweight spaceships, as well as convert gliders to lightweight spaceships and lightweight spaceships to middleweight spaceships. The large spark's ability to convert gliders into lightweight spaceships is made use of by double X.
The stop and go reaction, where a glider is converted to a block and then reflected 180 degrees, was found by Dean Hickerson in January 1992. The reaction can be used to construct higher-period oscillators such as this p184.
|Several other interactions|
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RLE: here Plaintext: here
- Main article: List of common oscillators
A four-fold version of this oscillator first appeared semi-naturally in December 2014 in a soup found by Richard Schank. A monomerized version, specifically the cis isomer, later appeared in an asymmetric soup found by Brett Berger on April 16, 2015. The trans version first appeared on May 7 in a soup also found by Berger, and the three-block version first appeared on October 15 in a soup found by Tomas Rokicki. Other three-block versions, with one of the blocks placed further away, were found by Adam P. Goucher in July and September 2016. After numerous appearances in symmetric soups, the bilaterally symmetric four-block twin bees shuttle first appeared in the C1 symmetry on April 1, 2022, in a soup found by Charity Engine.
The cis isomer is about 15.1% more common than the trans isomer.
There is a 5-glider component that turns any one-sided stabilization of the twin bees, such as a block, into a twin bees shuttle variant by adding the two B-heptominoes and a stabilizing block. This yields 7-glider syntheses for two-block variants, and 8-glider syntheses for some 3-block variants.
Other patterns featuring twin bees:
- "B-heptomino shuttle". The Life Lexicon. Stephen Silver.
- Robert Wainwright (September 1971). Lifeline, vol 3, page 4.
- Dean Hickerson's oscillator stamp collection.
- "Stop and go". The Life Lexicon. Stephen Silver.
- "Do-see-do". The Life Lexicon. Stephen Silver.
- Adam P. Goucher. "Statistics". Catagolue. Retrieved on October 27, 2018.
- Richard Schank (December 19, 2014). Re: Soup search results (discussion thread) at the ConwayLife.com forums
- Matthias Merzenich (April 16, 2015). Re: Soup search results (discussion thread) at the ConwayLife.com forums
- gameoflifeboy (May 7, 2015). Re: Soup search results (discussion thread) at the ConwayLife.com forums
- gameoflifeboy (October 15, 2015). Re: Soup search results (discussion thread) at the ConwayLife.com forums
- Apple Bottom (July 16, 2016). Re: Soup search results (discussion thread) at the ConwayLife.com forums
- Apple Bottom (September 26, 2016). Re: Soup search results (discussion thread) at the ConwayLife.com forums
- catglue (April 1, 2022). Message in #cgol on the Conwaylife Lounge Discord server
- iNoMed (July 29, 2022). Re: Oscillator Discussion Thread (discussion thread) at the ConwayLife.com forums