I soon established that it had been formed in a region where two ship flows were crossing from a pair of blocks which were the common enough product of an earlier encounter between two ships with a quite rare and directly on-line wide sym (spaceship in CA speak). MargLyn, as I could not help but name her, produced by far the best example of the decorated 3/7 speed engine which never reaches a stable configuration and eventually produces a persistent 1/2 speed block trail laying engine. (1/2 speed is the normal speed of ships and track/trail-laying engines under The Wild's Generations 345/3/6 rule, though there are many forms that move faster and slower along tracks, trails and other stable patterns.)

Even when I still thought 200,000 would be enough, I had been planning to develop a Perl script/extension for Golly which would pan and zoom patterns while generating animated GIFs. My second refactoring seems to have made it good enough to use for show and tell. This four minute animation of MargLyn starts with a wide shot of the cross flow, including one collision briefly at lower left which produces two blocks, and zooms in to where Marg and Lyn synergise. Arguably I might have done more to tidy up the zoom back out where it runs off the edge of the frame, but this was only ever intended to be a rough cut, and we do get to see the whole developing pattern clearly at an intermediate phase before zooming back in to a close view of the 3/7 engine, then back out again to show the whole pattern in the context of a rapidly growing block trail and more outgoing ships against the background of recently other formed collision debris, passing and incoming ships; stopping immediately before the first incoming ship disturbs the symmetry.

Yes, I do know it demands a sound track, and definitely something better than voice over.