In principle, one could construct a non-elementary knightship (the Geminoid construction is said to be capable of this - essentially it's a giant universal constructor that can be "programmed" to reconstruct itself an arbitrary distance from its initial position), but they're rather less interesting since they tend to be very large and not useful as building blocks.

In contrast an elementary object, like a knightship, tends to be nice and small, and therefore highly valued as a building block for more powerful systems. Orthogonal and diagonal gliders see a ton of use in complex Life systems, and it's probable that the new knightship will see good use too (once people start building and exploring the requisite tooling - guns, eaters, and other reactions).

See https://niginsblog.wordpress.com/2016/03/07/new-spaceship-sp... for a rundown of the difference.

It is definitely possible, and extremely probable, that extremely large "elementary" structures exist - but we lack the computational power to find such things.

> This table does not include oblique speeds, which causes little inconvenience because no elementary oblique ships are known.

Well, guess that needs to be updated :D

also self-contained glider that leave no structures behind and don't require structure to move are essential in repeating mechanism, since they leave the path in a known state, i.e.

https://copy.sh/life/?gist=f3413564b1fa9c69f2bad4b0400b8090&...

Another key point about this knightship, ignoring that it's elementary, is that it also moves at the fastest possible speed of 1/6 in an oblique direction. This had never been done before. The pre-existing non-elementary ships are all quite slow and it's hard to imagine them hitting the maximum possible speed.