c/2 challenge

[hotdogPi]

What is the longest non-infinite elementary c/2 forward mechanism you can find?

As a starter, this becomes a B-heptaplet in generation 23, and the first generation where it falls behind is generation 38. (If it falls behind and makes it up superstring-style, that doesn't end the run.)

Code: Select all

x = 5, y = 4, rule = B3/S23
o2bo$o3bo$o3bo$b4o!

(Now that I think about it, it should probably have been in sandbox.)

[Wyirm]

Are extensible c/2o partials allowed? They eventually stop moving, are finite in size, and can last arbitrarily long times.

[GUYTU6J]

Agree with the proposed move. Random quotes:
11-40

A honey farm predecessor reacting with a block edgeshoots a block a long way off.

Code: Select all

x = 7, y = 7, rule = B3/S23
2o$2o4bo$5bo$6bo2$4b2o$5bo!

27-62

A non-trivial example, but it contains an aircraft carrier:

Code: Select all

x = 27, y = 17, rule = B3/S23
16b2o$16b2o4$13bo$14b2o$13b2o4$25b2o$o22bo2bo$3o20b2o$2bo$2bo!

[Kazyan]

This three glider collision is a contender:

Code: Select all

x = 8, y = 9, rule = B3/S23
bo$2bo2bobo$3o3b2o$6bo3$2b3o$4bo$3bo!

It's used in the current synthesis of xs17_jhke0mqz1, in which we needed a long-lived c/2 mechanism to make it work.

[yujh]

First generation to fall behind is 46

Code: Select all

x = 6, y = 4, rule = B3/S23
4bo$2o3bo$bo3bo$2b4o!

[toroidalet]

Perhaps this is not in the spirit of the contest, but all 4 B-heptominoes simultaneously fail the advance in generation 288:

Code: Select all

x = 35, y = 5, rule = B3/S23
3o29b3o$o2bo27bo2bo$o6b3o3b3o3b3o3b3o6bo$o5bo2bo3bo2bobo2bo3bo2bo5bo$b
obo6bobo9bobo6bobo!

EDIT: even more dubiously, 398:

Code: Select all

x = 37, y = 11, rule = B3/S23
b3o29b3o$o2bo29bo2bo$3bo4b3o3b3o3b3o3b3o4bo$3bo4bo2bobo2bo3bo2bobo2bo
4bo$obo5bo7bo3bo7bo5bobo3$12bo11bo$12bo11bo$12bo11bo!

[yujh]

It’s probably the whole thing that stop, not part of it I believe