|View static image|
|Number of cells||7|
|Bounding box||8 × 3|
|Year of discovery||Unknown|
Die hard is a 7-cell methuselah (essentially a collision between a block and the traffic light sequence) that vanishes after 130 generations, which is conjectured to be the limit for vanishing patterns of 7 or fewer cells. Note that there is no limit for higher numbers of cells, as eight cells suffice to have a glider heading towards an arbitrarily distant blinker or pre-block.
The diehard evolutionary sequence
The original diehard is a semi-common sequence. In addition to a traffic light hitting a block, a common blinker predecessor can hit the same block, turning it into the diehard sequence. This version lasts 137 generations.
|Period-42 diehard hassler (Mitchell Riley, November 1, 2022)|
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"Die hard" as a general term
Alternatively, "die hard" or "diehard" may refer to any methuselah that eventually vanishes. Like with regular methuselahs, an arbitrarily long-lived diehard can be trivially constructed using only 8 cells from a single glider and either a blinker or a pre-block. Therefore, bounding box tends to be the preferred metric for the "size" of a diehard.
Soups in Conway's Game of Life lasting at least 500 generations before disappearing completely are reported by apgsearch versions v4.69 and above and referred to as "messless methuselahs" on Catagolue. As of July 2023, the longest-lasting known natural diehard lasts 1398 ticks, while the longest-lasting known semi-natural (i.e. symmetrical but still random) diehard has C4_4 symmetry and lasts 2500 ticks. Both soups were found by Charity Engine, the asymmetric soup on January 14, 2022, and the symmetric one in April 6th, 2023.
- Main article: Engineered diehard
Beginning in early 2022, there has been considerable interest in constructing artificial diehards within small bounding boxes.
In other rules
In HighLife, despite the instability of the traffic light sequence, the die hard still works, disappearing after 119 generations.