Choose by lifespan and outcome
Methuselah searches usually ask for a comparison: which seed stays active longest, which one disappears, and which one leaves stable ash. R-pentomino, Acorn, Diehard, and Edna answer those questions with very different scales and endings.
Use R-pentomino as the compact reference, Acorn for a longer small-seed transient, Diehard for complete extinction, and Edna as the large 31,192-generation benchmark.
Compare quickly
Methuselah comparison table
Use this table to pick the right runnable page before reading the full explanation.
| Pattern | Seed | Lifespan | Outcome | Run when you want |
|---|---|---|---|---|
| R-pentomino | 5 cells in 3 x 3 | 1,103 generations | 116 cells and 6 gliders | The classic compact reference |
| Acorn | 7 cells in 7 x 3 | 5,206 generations | 633 cells and 13 gliders | A longer small-seed transient |
| Diehard | 7 cells in 8 x 3 | 130 generations | Complete extinction | A long-lived pattern that vanishes |
| Edna | 149 cells in 20 x 20 | 31,192 generations | Large final ash | A large enumeration benchmark |
The name is about lifespan, not size
A methuselah starts small and takes a long time to settle. There is no single universal cutoff, but patterns that stabilize quickly are not usually treated as methuselahs.
The R-pentomino is the classic example: five cells, a 3 x 3 bounding box, and a stabilization time of 1,103 generations. That mismatch between small beginning and long history is the point.
Long-lived does not always mean surviving
Diehard is useful because it stays active for 130 generations and then disappears completely. It teaches a different lesson from the R-pentomino: visible activity is not the same as lasting ash.
Acorn pushes the other direction. Its seven cells produce a long, messy evolution before the reaction resolves. It is a better pattern when the goal is to watch a population curve rise, collapse, and rise again.
Reference points by seed size
The R-pentomino is the compact reference point: five live cells, a 3 x 3 bounding box, a 1,103-generation lifespan, and a final census of 116 cells including 6 gliders.
Acorn starts with seven live cells in a 7 x 3 bounding box and runs for 5,206 generations before stabilizing with 633 cells.
Diehard uses an 8 x 3 bounding box, stays active for 130 generations, and then disappears completely.
Edna is the extreme comparison point: a 149-cell methuselah in a 20 x 20 bounding box with a 31,192-generation lifespan.
The lab needs enough room
Methuselahs punish cramped boards. If the boundary cuts off debris or escaping gliders, the observed result is no longer the natural evolution of the seed.
That is why the simulator includes larger board sizes. For R-pentomino and acorn, a roomy grid is not a cosmetic setting. It changes whether the demonstration is honest.
Working takeaway
Choose the comparison by outcome first: compact long transient, longer small seed, extinction, or large benchmark. Then open the matching live pattern.
Fast answers
Common search questions
What makes a pattern a methuselah in Conway's Game of Life?
A methuselah starts from a small seed and stays active for an unusually long time before stabilizing or disappearing. The name describes the long transient, not one required seed size.
Which methuselah lasts longest in this comparison?
Edna is the large benchmark at 31,192 generations. Among the small seeds compared here, Acorn lasts 5,206 generations.
Which methuselah disappears completely?
Diehard stays active for 130 generations and then vanishes. That makes it the useful extinction comparison beside patterns that leave final ash.