L156
| L156 | |||||||||
| View static image | |||||||||
| Pattern type | Conduit | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Conduit type | Composite | ||||||||
| Input | Herschel | ||||||||
| Number of cells | 56 | ||||||||
| Bounding box | 29 × 29 | ||||||||
| Output orientation | Turned left | ||||||||
| Output offset | (17, -41) | ||||||||
| Step | 156 ticks | ||||||||
| Recovery time (ignoring FNG if any) |
62 ticks | ||||||||
| Minimum overclock period (ignoring FNG if any) |
Unknown | ||||||||
| Spartan? | Yes | ||||||||
| Dependent? | No | ||||||||
| Discovered by | David Buckingham | ||||||||
| Year of discovery | 1996 | ||||||||
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L156 is a composite conduit, one of the original sixteen Herschel conduits, discovered by Dave Buckingham on August 7, 1996. It is made up of three elementary conduits: HLx69R, RF28B, and BFx59H. After 156 ticks, it produces a Herschel turned 90 degrees counterclockwise at (17, -41) relative to the input as well as an extra glider to southeast.
Its recovery time is 62 ticks. It can be made Spartan by replacing the snake with an eater 1 in one of two orientations. In the pattern shown in the infobox, a ghost Herschel marks the output location.
Variants
Three variants are shown below. The first is the one in the infobox. The second uses an alternative RF28B to emit a glider to northeast instead. The third uses a structure similar to RNE-19T84 to produce two extra gliders.
| Three L156 variants. The third one is shown following a Fx77 (click above to open LifeViewer) RLE: here Plaintext: here |
The third L156 variant is a period doubler because it produces an extra block that destroys the next Herschel. It can be deleted using either a reflector (such as the p8 bumper + dependent conduit) or a set of conduits (e.g. R64 + F117, at the cost of impractically high repeat time). In most cases where only the edge-shooting northeast glider is needed, it is better to suppress the output Herschel as in RNE-19T84.
L156b
There is also a completely unrelated L156 conduit with the same step, repeat time and rotation, made out of the elementary conduits HL75P, PF35W and WFx46H. After 156 ticks, it produces a Herschel turned 90 degrees counterclockwise at (4, -41) relative to the input.
| Alternate L156 (L156_2 in the H-to-H collection provided with Golly) (click above to open LifeViewer) RLE: here Plaintext: here |
| A Spartan variant of L156b, followed by F166 (click above to open LifeViewer) |
Lx138
On January 1, 2012, Matthias Merzenich found Lx138, a composite conduit consisting of HL79B and BFx59H.[1] The HL79B stage evolves identically to HLx69R until generation 69, when a block and an eater 2 absorb the southeast glider to transform the original R-pentomino to B-heptomino output.
| Lx138 Herschel conduit (click above to open LifeViewer) RLE: here Plaintext: here |
Gallery
 HLx69R |
+ |  RF28B |
+ |  BFx59H |
| The elementary conduits that form L156 | ||||
See also
References
- ↑ Matthias Merzenich (January 1, 2012). Re: Finally trying out stable Herschel tracks... (discussion thread) at the ConwayLife.com forums
External links
- L156 at the Life Lexicon
- Buckingham on B-heptominos in oscillators at Paul Callahan's Page of Conway's Life Miscellany