Thread for basic questions

[Macbi]

Is a 10 x 10 solid square of cells glider constructible? And if not is there a Garden of Eden predecessor?

What, garden of edens aren’t meant to have predecessors. A pattern with predecessors doesn’t mean it must have glider synthesis, although I believe a 10x10 is not hard.

They mean 'if not, is there a predecessor which is a Garden of Eden'.

In any case, I think it's been long established that it's possible to construct any glider convoy.

[ihatecorderships]

Is a 10 x 10 solid square of cells glider constructible? And if not is there a Garden of Eden predecessor?

What, garden of edens aren’t meant to have predecessors. A pattern with predecessors doesn’t mean it must have glider synthesis, although I believe a 10x10 is not hard.

They mean 'if not, is there a predecessor which is a Garden of Eden'.

In any case, I think it's been long established that it's possible to construct any glider convoy.

I think they mean whether this has a synthesis:

Code: Select all

x = 10, y = 10, rule = B3/S23
10o$10o$10o$10o$10o$10o$10o$10o$10o$10o!

[Macbi]

You're right. I believe that one is an open problem.

[Herschel of Ostropol]

Is a 10 x 10 solid square of cells glider constructible? And if not is there a Garden of Eden predecessor?

What, garden of edens aren’t meant to have predecessors. A pattern with predecessors doesn’t mean it must have glider synthesis, although I believe a 10x10 is not hard.

What I meant was a predecessor that is a GoE. Sorry for the confusion.

Edit: What is the smallest non constructible solid rectangle of cells?

[ihatecorderships]

How would I synthesize the xs21 that forms?

Code: Select all

x = 26, y = 25, rule = B3/S23
9b3o2$7bo$7bo$7bo10b2o$11bo3bob3o$9bo5b5o$2bo5bo8bo$bobo4b2o5bo2b2obo
$o3bo8b3o2b4o$bobo16bo$2bo5$23b2o$9b3o10bo2bo$8b5ob2o6bobo$8bobobo3bo
6bo$11b2ob2o$13bo2$10b2o$10b2o!

[wwei47]

How would I synthesize the xs21 that forms?

Code: Select all

x = 26, y = 25, rule = B3/S23
9b3o2$7bo$7bo$7bo10b2o$11bo3bob3o$9bo5b5o$2bo5bo8bo$bobo4b2o5bo2b2obo
$o3bo8b3o2b4o$bobo16bo$2bo5$23b2o$9b3o10bo2bo$8b5ob2o6bobo$8bobobo3bo
6bo$11b2ob2o$13bo2$10b2o$10b2o!

This predecessor might help you.

Code: Select all

x = 22, y = 19, rule = B3/S23
12bo$11bobo$10bo3bo$3bo7bobo2b3o$4bo7bo$2b3o14bo$6bo12bo$5bobo7b2o2bo
$6bo5b2o2bo$7b3o2bob2o$2b2o6bobo6b2o$2ob2o4b2obo5bo2bo$4o4bo2bo6bo2bo
$b2o5bobo8b2o$9bob3o$2b2o7bo2bo$10bo2bo6b2o$11b2o6b2o$21bo!

[dvgrn]

Is a 10 x 10 solid square of cells glider constructible? And if not is there a Garden of Eden predecessor?

It's not known to be glider-constructible, but it might well be. There's pretty definitely a Garden of Eden predecessor, in the sense that if you track a 10x10 square of ON cells backward far enough, you'll eventually get to a predecessor that's so big that it's pretty much guaranteed to be a Garden of Eden -- or if it isn't, then check its parent, until you find one.

But that doesn't mean that all predecessors of a 10x10 block necessarily trace back to a Garden of Eden. If I had to guess, I'd say that a 10x10 block probably is not a great^N-grand-orphan, with no ancestors farther back than some definite number of ticks. But I don't have anything concrete to base that on, other than some experimentation with JLS:

Code: Select all

x = 16, y = 16, rule = B3/S23
bobo3bo2bo2bobo$bobo5bo2bo$2b2ob3o3b2obo$3b2o3bob2obo$obo4bo3bobobo$6b
3obob2o$b2ob2obo5b2o$4b3o2b2o3bo$3b2obo3bob2o$2bobo2bobob4o$2bo2bobo3b
o3bo$5bo4bo2bo$o2b4o5b3o$b3o3bob2ob2o$2bo2bo6bo2bo$bo3bo3b2o3bo!
#C [[ AUTOSTART GPS 1 T 0 PAUSE 3 T 3 PAUSE 4 LOOP 4 ]]

There's just a lot of space for uncertainty between the relatively few patterns that are known to be glider-constructible, and the relatively few other patterns that are known to be great^N-grand-orphans. As we try to track patterns backward in time, they tend to get bigger, and therefore harder to prove anything about one way or another.

[Herschel of Ostropol]

Is there a still life that has a unusually large population for its commonality? Similar to a Pulsar for oscillators.

[hotdogPi]

Is there a still life that has a unusually large population for its commonality? Similar to a Pulsar for oscillators.

The most likely candidate would be the O quad-loaf, but it's nowhere near as common as the pulsar.

[dvgrn]

Is there a still life that has a unusually large population for its commonality? Similar to a Pulsar for oscillators.

The most likely candidate would be the O quad-loaf, but it's nowhere near as common as the pulsar.

You could make a case that the things that have appeared more than once in the xs40 tabulation, and a few like the professor in higher bit counts, are in some sense "uncommonly common". But as hotdogPi says, even the omnibus isn't really proportional in any way to the pulsar's size-vs-common-ness.

[dani]

Is there anything fundamentally impossible about this plan?

- Create an interpreter for some programming language in CGoL. (already done, APGsembly, but I don't know if it could support everything else)
- Implement a lifelib-style programming interface so you can run search programs on it.
- Write a search program that searches for glider collisions that produce a desired object.
- The pattern runs the script, takes the output, and turns it into an actual glider synthesis of the object, creating it in a desired place.

I actually think this would be significantly easier than the idea someone had years back about making a spaceship search program that outputs spaceships directly to the field. It's really hard to, on the fly, come up with a compatible predecessor for every spaceship, but I feel as if glider syntheses would be easier. Especially if it was a slow salvo synthesis.

-----

Also, in response to this:

Is there a still life that has a unusually large population for its commonality?

I think maybe shiptie could count, especially if you consider the double shiptie from a fleet as a single object. A single one is ~392.2x as common as the next common xs12, table on table.

[Herschel of Ostropol]

How common is the loaf weld barge?:

Code: Select all

x = 5, y = 5, rule = B3/S23
b2o$o2bo$obobo$bobo$2bo

[Herschel of Ostropol]

Are there any known unconstructable stable patterns?

[Book]

How common is the loaf weld barge?:

Code: Select all

x = 5, y = 5, rule = B3/S23
b2o$o2bo$obobo$bobo$2bo

Paste the rle into Catagolue objects. It's called barge siamese loaf. Click the link to the wiki. All is revealed.

[yujh]

Are there any known unconstructable stable patterns?

not sure what you meant, but there are still lives that are proved to have no other parents like https://www.conwaylife.com/forums/viewt ... 58#p140258

[hotdogPi]

This reaction is known, but I can't find any two traffic light factories that can combine to do this (create a LWSS). Do any exist?

Code: Select all

x = 9, y = 5, rule = B3/S23
6bo$bo3bobo$4bo3bo$3o2bobo$6bo!

[Pavgran]

Is there anything fundamentally impossible about this plan?

- Create an interpreter for some programming language in CGoL. (already done, APGsembly, but I don't know if it could support everything else)
- Implement a lifelib-style programming interface so you can run search programs on it.
- Write a search program that searches for glider collisions that produce a desired object.
- The pattern runs the script, takes the output, and turns it into an actual glider synthesis of the object, creating it in a desired place.

I see nothing impossible about this. APGsembly would need just another module to support programmable synthesis but that's doable. Perhaps even already existing stable construction arms can do the job with a small signal translation module.
But the whole construction would take a very long time to synthesize even such a simple object as eater.

[Herschel of Ostropol]

Could greyship edges be used to create a c/2, or slower, light-speed bubble?

Edit:
Is there a shuttle (or other oscillator) that does the following?:
The oscillator places an object that stabilizes within oscillator's period, which does not disrupt the oscillator's sequence. But, the object does not destroy, or get destroyed by, the oscillator in any of the next cycles.
OR
Is there a still life with an island which, when the island destroyed, replaces the destroyed island?

[mniemiec]

Is there anything fundamentally impossible about this plan?

- Create an interpreter for some programming language in CGoL. (already done, APGsembly, but I don't know if it could support everything else)
- Implement a lifelib-style programming interface so you can run search programs on it.
- Write a search program that searches for glider collisions that produce a desired object.
- The pattern runs the script, takes the output, and turns it into an actual glider synthesis of the object, creating it in a desired place.

Given that life is computationally universal, this is certainly theoretically possible. Whether it is practical is a totally different matter. There are many theoretically computable problems that are totally impractical. E.g. simulating a 2D CA on a Turing machine, or in Rule 110. Another trivial example is synthesizing anything from 17 gliders; the time and space contraints explode so quickly that it's not even practical for synthesizing a block.

[Macbi]

Could greyship edges be used to create a c/2, or slower, light-speed bubble?

If it travelled at c/2 then by definition it wouldn't be a lightspeed bubble. Perhaps you want a bubble that travels at c/2 perpendicular to the stripes in the zebra agar? I believe such a thing is unknown, but we have all the components except the front corners.

[Herschel of Ostropol]

What is this called?

Code: Select all

x = 5, y = 3, rule = B3/S23
2b3o$
bo2bo$
2ob2o!

It fits in a 5 x 3 bounding box and it stabilizes after 463 generations with two escaping gliders. The remaining ash fits in a 112 x 89 bounding box. It emits four herschels.

And yet I have never seen of this reaction before. Is this used in anything? And if not, can it be?

[hotdogPi]

What is this called?

Code: Select all

x = 5, y = 3, rule = B3/S23
2b3o$
bo2bo$
2ob2o!

It fits in a 5 x 3 bounding box and it stabilizes after 463 generations with two escaping gliders. The remaining ash fits in a 112 x 89 bounding box. It emits four herschels.

And yet I have never seen of this reaction before. Is this used in anything? And if not, can it be?

I've seen it. Someone proposed that it be called "digital 8" due to one of its phases. It's nowhere near as common as newly named objects like the blonk-tie and the U-turner, though.

[Sokwe]

What is this called?

Code: Select all

x = 5, y = 3, rule = B3/S23
2b3o$
bo2bo$
2ob2o!

As hotdogPi noted, it is sometimes called "digital 8". It is also sometimes called "grate".

[hotdogPi]

I've asked this before, but I've never gotten an answer one way or the other. This is from Lifeline Volume 1.

Code: Select all

ob2o5b3o4bo8b3o4b2o6b2o6b2o$3o5b3o5b3o5b2o7bo7bo7bo$bo7bo6bobo6b2o6bo
7b3o5b2o$18bo14b3o6bo7b2o!
[[ THUMBSIZE 3 HEIGHT 320 WIDTH 1400 ]]
[[ Y -3 ]]
[[ THUMBZOOM 24 ]]
[[ COLOR LABEL Gray ]]
[[ LABEL  1 -4 4 "B" ]]
[[ LABEL  9 -4 4 "C" ]]
[[ LABEL 17 -4 4 "D" ]]
[[ LABEL 25 -4 4 "E" ]]
[[ LABEL 33 -4 4 "F" ]]
[[ LABEL 41 -4 4 "H" ]]
[[ LABEL 49 -4 4 "I" ]]
}}

Note that A is missing. Was this the A-heptomino? I figure that it could have been named that and then figured out before Volume 1 was published. (Now the sequence is called "moth", due to its similarity to butterfly.)

Code: Select all

x = 4, y = 4, rule = B3/S23
2b2o$b2o$2o$o!

[ihatecorderships]

Why has interest in conduits declined these days?