Self-synchronized linear replicator

Self-synchronized linear replicator
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Pattern type	Puffer
Number of cells	16702
Bounding box	65676 × 65520
Direction	Orthogonal
Period	1048576
Speed	256c/1048576
Discovered by	lumi
Year of discovery	2026
Pattern files Macrocell selfsynchronizedlinearreplicator.mc RLE selfsynchronizedlinearreplicator.rle

Self-synchronized linear replicator is a single-channel universal constructor pattern assembled by lumi with help from inductivetype and russellsprouts, and posted on May 17, 2026. Nine days previous, lumi had published a similar single-channel linear propagator design, but it was much less HashLife-friendly because each child replicator was created in a different phase from its parent. That pattern in turn was a rebuild of an initial much larger design completed back in February 2026.

Design and Construction

In the self-synchronized linear replicator, the construction recipe glider stream is inserted into the child's memory loop using a temporary Snark inserted partway down the loop. This avoids the phase offset between parent and child that was seen in the previous version.

Like the previous design, this replicator uses the Simkin gun construction arm invented by russellsprouts, which makes possible a huge improvement in construction efficiency over the original linear propagator.

To qualify as a true self-replicating pattern, a linear propagator has to remain undamaged and capable of creating another child in future cycles, if the first constructed child is somehow removed. For the new design it was necessary to include an edgy eater seed directly on the single channel lane, to block each parent from attempting to construct additional child replicators in the same location as the first child. Using russellsprouts' large database of direct still life construction recipes, lumi combined three such recipes to form the seed in just 14 fast gliders.

The temporary Snark that is used for inserting the copied recipe has to be partially destroyed at the right time, after it has completed its work of filling the memory loop, but before the inserted recipe completes a full loop.

Unlike the previous design, the construction is two sided, with both NE and SW salvos. The recipe glider stream just barely fits in a p524288 glider loop.