Quad
Quad  
View animated image  
View static image  
Pattern type  Oscillator  

Oscillator type  Muttering moat  
Family  Barberpole  
Number of cells  16  
Bounding box  6 × 6  
Period  2  
Mod  1  
Heat  8  
Volatility  0.40  
Strict volatility  0.40  
Rotor type  Clock  
Discovered by  Robert Kraus  
Year of discovery  1971  
 
 
 

Quad (or barberpole intersection^{[1]}) is a period2 oscillator and muttering moat that was found in April 1971 by Robert Kraus.^{[2]} It has the same rotor as the clock. It and mold are the only flippers that fit inside a 6 × 6 bounding box; however, mold is period 4.
This oscillator first occurred naturally on December 28, 2015, in a soup submitted to Catagolue by Adam P. Goucher. A 12glider synthesis was constructed the day following its occurrence by Tanner Jacobi.^{[3]}
Information on this oscillator's natural occurrence with respect to other naturallyoccurring patterns is currently unknown.
Formation
Despite having fourfold symmetry, quads typically form via twofold symmetry only. As shown below, there are two lumps of muck in the center, and the two outside objects shown can be anything with the same front two rows that does not interfere later.
Quad predecessor (click above to open LifeViewer) RLE: here Plaintext: here 
See also
References
 ↑ Conway's Life Glossary at Paul Callahan's Page of Conway's Life Miscellany
 ↑ Dean Hickerson's oscillator stamp collection. Retrieved on March 14, 2020.
 ↑ Tanner Jacobi (December 29, 2015). Re: Soup search results (discussion thread) at the ConwayLife.com forums
External links
 Quad at the Life Lexicon
 Quad at Adam P. Goucher's Catagolue
 The 98 sixteenbit period 2 oscillators at Mark D. Niemiec's Life Page (download pattern file: 16/16qd.rle)
 16P2.19 at Heinrich Koenig's Game of Life Object Catalogs
 Patterns
 Oscillators with 16 cells
 Periodic objects with minimum population 16
 Patterns with 16 cells
 Patterns found by Robert Kraus
 Patterns found in 1971
 Patterns that can be constructed with 8 gliders
 Oscillators
 Barberpole variants
 Muttering moats
 Oscillators with period 2
 Oscillators with mod 1
 Oscillators with heat 8
 Oscillators with volatility 0.40
 Oscillators with strict volatility 0.40
 Oscillators with rotor Clock
 Patterns with 90degree rotation symmetry
 Flipping oscillators
 Natural periodic objects