Kazyan wrote:There still hasn't been a weekender gun, has there? On that topic, I checked Catagolue and found a 6-glider synthesis of xs14_4aaraa4...which shaves a glider off the weekender synthesis. I don't know how that affects the repeat time, though.
With a little adjustment, it doesn't affect repeat time at all -- still 475 ticks. The recipe is at the bottom of this post.
I've been wary of building a weekender gun, for fear of getting into Interminable Optimization Limbo.
However, I would
be interested in a glider-to-weekender converter -- which of course could be turned into a weekender gun of any period just by adding the appropriate glider gun. With any luck, a G-to-W converter will be so safely enormous that no one will be tempted to bother spending time reducing the bounding box.
87 gliders in four salvos is a lot of glider splitters, edge shooters and timing adjustments. Maybe it's time to write a script to at least semi-automate this kind of construction.
Here's a start at a generalized G-to-multi-G design. There are four major stages to worry about:
1) A single input glider produces eight gliders, one to trigger each of eight stable half-shotguns.
2) Each of the eight gliders is fanned out to produce a set of gliders, moving parallel to each other a safe (and adjustable) distance apart.
3) Each set of gliders passes through timing and/or color adjustment devices to put them in exactly the right positions relative to each other.
4) Each set of gliders enters its dedicated set of edge-shooter circuits to produce the desired half-salvo.
It seems like a good idea to work on that list in reverse order. The edge-shooter placement may turn out to be the most difficult thing to automate, since in some cases multiple signals might be needed to support the placement of a single glider.
Let's see how this part works out for one of the salvos -- say the one from the northeast:
Code: Select all
x = 99, y = 109, rule = LifeHistory
The two colors mark a plausible division, with a dozen gliders constructed from the NW side, and the other dozen from the SE side. There are some fairly close placements here, but it looks as if it should be possible to get by with just the standard inserters:
Code: Select all
x = 312, y = 903, rule = LifeHistory
It doesn't seem like a good idea to worry too much about guaranteeing a 475-tick repeat time -- the edge shooters for some of the weekender sub-salvos may end up being a lot more expensive if the first insertions have to wait for the tail end of the previous salvo to go by. But it seems to make sense to disallow signal crossings throughout the circuitry, so that if period N works, period N+1 is also guaranteed to work.
Code: Select all
#O Martin Grant
#C 87-glider synthesis of weekender spaceship.
#C Original synthesis found 25 January 2015,
#C based on initial work by Tanner Jacobi.
#C Optimization by Chris Cain and Tanner Jacobi.
x = 462, y = 467, rule = B3/S23
Probably the next thing is to do a similar analysis of the other three salvos, to make sure they're compatible with simple edge shooters. Offhand I don't see any unbuildable combinations -- but I've had a lot of unpleasant surprises sneak up on me, so it pays to be really careful.
Anyone see any serious trouble spots? Further bulletins as events warrant.