Unique father problem
| Unique father problem | |||||||
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| Pattern type | Strict still life Problem | ||||||
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| Number of cells | 374 | ||||||
| Bounding box | 32 × 26 | ||||||
| Static symmetry | Unspecified | ||||||
| Discovered by | Ilkka Törmä Ville Salo | ||||||
| Year of discovery | 2022 | ||||||
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The unique father problem is the following question, posed by John Conway in 1972 in Lifeline Volume 6 with an associated $50 cash prize,[1] along with the grandfather problem:
- Is there a stable configuration whose only father is itself (with some fading junk some distance away not being counted)?
The problem was answered positively by Ilkka Törmä and Ville Salo on January 13, 2022, with a 26×32 still life consisting of blocks and snakes.[2]
Also see
References
- ↑ Robert Wainwright (October 1972). Lifeline, vol 6, p. 1.
- ↑ Ilkka Törmä (January 13, 2022). Re: Unproven conjectures (discussion thread) at the ConwayLife.com forums
External links
Categories:
- Patterns
- Periodic objects with minimum population between 300 and 399
- Patterns with between 300 and 399 cells
- Patterns found by Ilkka Törmä
- Patterns found by Ville Salo
- Patterns found in 2022
- Patterns that can not be constructed with gliders
- Still lifes
- Strict still lifes
- Strict still lifes with 374 cells
- Patterns with 180-degree rotation symmetry
- Problems