otismo wrote: ↑March 31st, 2020, 2:45 am

...four out of six with one bogy, and maybe time to start looking at slide guns, etc.

Yeah, but it's only a very theoretical four out of six. With those rake periods, your second and later constructions won't work because

**(a)** the gliders are coming in way too soon, before the previous reaction has finished, and

**(b)** the second round of gliders won't line up with the hook-with-tail wick.

In other words, your construction site will be traveling orthogonally to the right at c/2, whereas you really need it to be traveling obliquely at a (5,-4) step, with a repeat rate somewhere around this (or it can be slower):

Code: Select all

```
x = 65, y = 66, rule = B3/S23
2bo$obo$b2o53bo$54b2o$55b2o$59bo$59bobo$3bobo53b2o$4b2o$4bo6$8bo$6bobo
$7b2o31bo$38b2o$39b2o$43bo$43bobo$9bobo31b2o$10b2o$10bo6$14bo$12bobo$
13b2o9bo$22b2o$23b2o$27bo$27bobo$15bobo9b2o$16b2o$16bo4$20b2o$19b2o$
14b2o5bo$14bo$11b2obo$11bobo$31bo$30b2o4b2o$30bobo2b2o$37bo4$47bo$46b
2o4b2o$46bobo2b2o$53bo4$63bo$62b2o$62bobo!
```

Here I've replaced the blinker cleanup glider with one that would be a little easier to construct near its neighbors.

Unfortunately there aren't any elementary rakes that alternate between glider colors the way these streams do. So you'd have to use higher-period rakes, twice as many of them, and interleave the outputs.

There might be some way to find vertical rakes and horizontal rakes with slightly different periods to account for the slight Doppler effect as the construction site recedes more quickly from one rake than from the other, and generate the gliders coming SW by colliding gliders from the NW and gliders from the SE. (Can't use diagonal high-period backrakes, like ones based on Corderships, because they'd have to move over a half-diagonal after every glider -- we don't have anything like that except for huge slow self-constructing stuff.) The math is a little tricky, but not too bad -- but it definitely won't work to just ignore the problem and drop in any old rakes.

Short summary: a universal-constructor-based solution is actually the

*easy* way to build a hook-with-tail stacker. Slide guns might not be too bad either, but you would still have to figure out the Doppler-shift math.