Octagon 2
| Octagon 2 | |||||||||
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| Pattern type | Oscillator | ||||||||
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| Number of cells | 16 | ||||||||
| Bounding box | 8 × 8 | ||||||||
| Frequency class | 29.3 | ||||||||
| Period | 5 (mod: 5) | ||||||||
| Heat | 16 | ||||||||
| Volatility | 0.80 | 0.80 | ||||||||
| Kinetic symmetry | *k | ||||||||
| Discovered by | Arthur Taber Sol Goodman | ||||||||
| Year of discovery | 1971 | ||||||||
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Octagon 2 is the first known period-5 oscillator, discovered in 1971 independently by Sol Goodman and Arthur Taber;[1] the name is due to the latter. Its discovery was first reported in Lifeline Volume 1.[2] In terms of its 16 cells, it is the second smallest possible period-5 oscillator after pseudo-barberpole, however it is not known if it is the only 16-cell period-5 oscillator.[3]
A 5-glider synthesis for this oscillator was found and submitted to Catagolue by Carson Cheng[4] in May 2022.[5]
As a weak sparker
While nowhere near as robust as many other period-5 sparkers, octagon 2 still has a few uses.
| A p5 corner dot sparker that relies on an octagon 2 in the back (click above to open LifeViewer) Catagolue: here |
| p50 traffic jam (click above to open LifeViewer) RLE: here Plaintext: here Catagolue: here |
Phase shifting
An octagon 2 can be used as a block catalyst on each side to skip a phase.
| Four p24 shuttles hassling an octagon 2. Found by Nicolay Beluchenko in March 2009[6] (click above to open LifeViewer) RLE: here Plaintext: here Catagolue: here |
| Four Merzenich's p64s hassling an octagon 2 (click above to open LifeViewer) RLE: here Plaintext: here Catagolue: here |
| Four 50P9s hassling an octagon 2 (click above to open LifeViewer) Catagolue: here |
| Four 60P7s hassling an octagon 2 into p14 (click above to open LifeViewer) Catagolue: here |
Occurrence
- See also: List of common oscillators
Octagon 2 is about the twenty-sixth most common naturally-occurring oscillator in Achim Flammenkamp's census, being about as common as unix.[7] On Catagolue, it is the most common period 5 oscillator, being more common than fumarole.[8]
In even 8-fold symmetry (D8_4), it is the nineteenth most common object and the fifth most common oscillator, appearing in 1 in 80 soups.
In other rules
In B3-a/S23, this pattern skips a phase and becomes a period 4 pattern.
See also
References
- ↑ Dean Hickerson's oscillator stamp collection. Retrieved on March 14, 2020.
- ↑ Robert Wainwright (March 1971). Lifeline, vol 1, page 5.
- ↑ Matthias Merzenich (October 4, 2025). Re: Oscillator Discussion Thread (discussion thread) at the ConwayLife.com forums
- ↑ Carson Cheng (July 15, 2022). Message in #cgol on the Conwaylife Lounge Discord server
- ↑ shinjuku (#2425153643) (May 6, 2022). Job triggered by Adam P. Goucher at GitLab Catagolue project. Retrieved on May 13, 2022.
- ↑ New Oscillators at Game of Life News. Posted by Heinrich Koenig on April 14, 2009.
- ↑ Achim Flammenkamp (September 7, 2004). "Most seen natural occurring ash objects in Game of Life". Retrieved on January 15, 2009.
- ↑ Adam P. Goucher. "Statistics". Catagolue. Retrieved on October 27, 2018.
External links
- Octagon 2 at the Life Lexicon
- Octagon 2 at Adam P. Goucher's Catagolue
- The 1 sixteen-bit period 5 oscillator at Mark D. Niemiec's Life Page (download pattern file: 16/16oc.rle)
- 16P5.1 at Heinrich Koenig's Game of Life Object Catalogs
- Patterns
- Patterns with Catagolue frequency class 29
- Natural periodic objects
- Oscillators with 16 cells
- Periodic objects with minimum population 16
- Patterns with 16 cells
- Patterns found by Arthur Taber
- Patterns found by Sol Goodman
- Patterns found in 1971
- Patterns that can be constructed with 5 gliders
- Oscillators
- Oscillators with period 5
- Oscillators with mod 5
- Oscillators with heat 16
- Oscillators with volatility 0.80
- Oscillators with strict volatility 0.80
- Oscillators with *k symmetry
- Sparkers
- Sparkers with period 5
- Weak sparkers