- It needs some free space around the ash field to work in.
- It can't completely prevent secondary gliders/spaceships from being produced as the ash is being cleared; anything important in the way of this secondary radiation will need to be armored (i.e. riprap).

Code: Select all

```
x = 15, y = 18, rule = B3/S23
12b3o$14bo$13bo$9b2o$8bobo$10bo10$2o$b2o$o!
```

Code: Select all

```
x = 225, y = 237, rule = B3/S23
223bo$133bo58b2o28bobo$102b2o29bo28b3o26bo2bo27bobo$102b2o29bo58b2o29b
o4$102b3o27b3o27b3o27b3o27b3o$104bo29bo29bo29bo29bo$103bo29bo29bo29bo
29bo$99b2o28b2o28b2o28b2o28b2o$98bobo27bobo27bobo27bobo27bobo$100bo29b
o29bo29bo29bo10$90b2o28b2o28b2o28b2o28b2o$91b2o28b2o28b2o28b2o28b2o$
90bo29bo29bo29bo29bo17$132b3o$134bo$133bo$129b2o$128bobo$130bo61b3o$
194bo$193bo$189b2o$188bobo$190bo5$120b2o$121b2o$120bo3$180b2o$181b2o$
180bo12$162b3o$164bo$163bo$159b2o$158bobo$160bo10$150b2o$151b2o$150bo
13$132b3o$134bo$133bo$129b2o$128bobo$130bo10$120b2o$121b2o$120bo17$
102b3o$104bo$103bo$99b2o$98bobo$100bo10$90b2o$91b2o$90bo3$72b3o$74bo$
73bo$69b2o$68bobo$70bo10$60b2o$61b2o$60bo17$42b3o$44bo$43bo$39b2o$38bo
bo$40bo10$30b2o$31b2o$30bo9$12b3o$14bo$13bo$9b2o$8bobo$10bo10$2o$b2o$o
!
```

IF the volley has reached the other side with the first glider intact:

- We're away from the face. Advance one half diagonal for the next volley.

OTHERWISE

- We don't know if the interaction with the volley has added any objects beyond the current half-diagonal. Retreat many half diagonals for the next volley.

In fact most of the volleys will be away from the ash face and won't interact with the ash at all. I didn't show such "probe" volleys in the example above. But this algorithm will mean that almost all interactions with ash objects will be edge interactions.

Some other complications:

- The ash may well launch glider back to where the volley came from. It's probably a good idea to arrange for any construction elbows to be well away from the launch area immediately after launch.

- On the other side of the ash face there is some risk of the detection mechanism for the first glider being fouled by a stray glider from the ash. I don't have a good solution for this. Any leftover gliders from the volley should probably be cleaned up as well but doing so without fouling on stray gliders will by tricky.

- The interaction of the volleys with the ash may produce crystals or other cyclic behaviour. For example, without the third glider, these two gliders have a block -> loaf -> barge -> ship -> block cycle:

Code: Select all

```
x = 7, y = 6, rule = B3/S23
4b3o$6bo$5bo$b2o$obo$2bo!
```