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## Thread for basic questions

For general discussion about Conway's Game of Life.

### Re: Thread for basic questions

look around the edges of a pattern until you hit a live cell, check the entire polyomino, and see if it matches any of the 16 glider orientations, reflections, and phases.
if it's a glider, delete it and mark the glider location, phase, and orientation.
if it's not, keep searching.

no gliders detected? run pattern until bounding box grows at least X cells bigger.

checking should start at generation Y.
you choose X and Y
c(>^x^<c)~
This is Fluffy the cat.
Fluffy wants to discover new things that everyone likes.
Fluffy likes to watch spaceship guns in Golly.

There’s one problem,

Fluffy doesn’t exist :(

Redstoneboi

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### Re: Thread for basic questions

Once the soup has been run to stabilisation (just steal the code from apgsearch or something), here are 2 tests (in pseudocode) to help guess if there are escaping objects (if you mean gliders as in any spaceship):
`run pattern to stabilisationoptionally run pattern some amount of generations more (to lower density if it's expanding)check density (50% soup is roughly 2%=.02)if density < 0.001 (change based on preference)//spaceships or puffers probably exist. lower threshold to decrease p-value (you can just skip this step if you want)   return trueelse   save dimensions of bounding boxrun 10000 (also arbitrary, probably too small) generationsif new length - old length > 300 (probably too large) || new width - old width > 300   return trueelse   return false//for those who want to make surereturn [new length - old length, new width - old width]`

if you're just looking for gliders (escaping XWSS, loafers, etc are fine), then the method is a little more complicated.
`x = 4, y = 2, rule = B3/S23ob2o\$2obo!`

(Check Gen 2)

toroidalet

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### Re: Thread for basic questions

Macbi wrote:What's the easiest way in a Golly script to run a pattern to stabilization, detecting any escaping gliders?

Most often I've just borrowed the relevant pieces of the old pre-apgluxe apgsearch script, as toroidalet suggests.

Seems like I've rewritten Redstoneboi's method several times in different languages, including in C++ when Gabriel Nivasch's 'catalyst' got turned into 'catfind' to hunt for the boojum reflector. But hunting for live cells all the way around the edges of a pattern, and then hunting all over again a few ticks later, is a lot less efficient than just running the pattern for (big-HashLife-step) and using apgsearch's tricks to get rid of escaping gliders.

Macbi wrote:I actually had a clever idea for shrinking the size of the "seed" still life, down to only 110 cells!

Whatever complicated circuitry is needed, we can no doubt construct it using a (not slow) single channel salvo. So instead of actually using that circuitry as our seed, we can use a rectifier loop (population 110) large enough to store that recipe. Then we can begin our construction by loading our recipe into the loop, as slowly as we like. Then to get our elbow block and hand we explode one of the rectifiers by inserting a glider into the loop too close to another one.

So if let's say your definition of "slow" is "at least a billion ticks apart", then you can just make the rectifier loop a billion-tick loop. Then to get two gliders 106 ticks apart, you could send a glider at T=0 and the next at T=1,000,000,106. Nice!

Macbi wrote:I haven't actually done the hard work yet of trying each possible explosion to find one that places an elbow correctly without any escaping gliders, but I'm sure it won't be that hard. Considering that we can also have gliders in the loop take part in the explosion, there are thousands of possibilities. So I think it's very likely that one of them works.

Yeah, not worried about that either -- some combination is bound to work.

However, the rectifier has a repeat time of 106, whereas current single-channel recipes go down to 90-tick separation. We have simeks' assurance that higher repeat times are no problem -- probably to up above 200 ticks, let alone 150 or 106 -- but I'm not sure we have enough recipes available right now to prove universality.

dvgrn
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### Re: Thread for basic questions

Thanks to everyone for the hints on detecting escaping gliders!

dvgrn wrote:However, the rectifier has a repeat time of 106, whereas current single-channel recipes go down to 90-tick separation. We have simeks' assurance that higher repeat times are no problem -- probably to up above 200 ticks, let alone 150 or 106 -- but I'm not sure we have enough recipes available right now to prove universality.
I believe the toolkit in this post is sufficient. It uses a traffic-light as an elbow, but that still shouldn't be too hard to arrange.

Macbi

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### Re: Thread for basic questions

Is it feasible to make a unit cell that has 2 or more states, using a sparser flow of gliders/spaceships to represent state 2 (or 3 or 4 or 5)?

Another question: Imagine that an AI hooked up to a UC emerged from complex switch engine interactions in a Sparse Life universe. What would be the best way for it to defend against switch engines and gliders flying in its direction? Building walls? Shooting *WSSs in random directions?

KittyTac

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### Re: Thread for basic questions

KittyTac wrote:Is it feasible to make a unit cell that has 2 or more states, using a sparser flow of gliders/spaceships to represent state 2 (or 3 or 4 or 5)?

Another question: Imagine that an AI hooked up to a UC emerged from complex switch engine interactions in a Sparse Life universe. What would be the best way for it to defend against switch engines and gliders flying in its direction? Building walls? Shooting *WSSs in random directions?

first question: depends on implementation
second:
it wouldn't react fast enough
but given enough time and space it might think this way:
"walls. WALLS. MORE BLOCK WALLS"
"what if the walls fail? what if i die?"
"hmmm, what if i created another copy of myself"
"that way, even if my armor fails and i die, the other one could live on and transfer my knowledge"
and a replicator is born more natural than ever.

it would construct a wall, then replicate, then expand the wall and repeat. the space and time it takes to do this i don't know.
c(>^x^<c)~
This is Fluffy the cat.
Fluffy wants to discover new things that everyone likes.
Fluffy likes to watch spaceship guns in Golly.

There’s one problem,

Fluffy doesn’t exist :(

Redstoneboi

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### Re: Thread for basic questions

KittyTac wrote:What would be the best way for it to defend against switch engines and gliders flying in its direction? Building walls? Shooting *WSSs in random directions?

Building IceNine, clearly.
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Apple Bottom

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### Re: Thread for basic questions

Apple Bottom wrote:
KittyTac wrote:What would be the best way for it to defend against switch engines and gliders flying in its direction? Building walls? Shooting *WSSs in random directions?

Building IceNine, clearly.

I know this is a joke, but building IceNine would just be a suicide bombing.
c(>^x^<c)~
This is Fluffy the cat.
Fluffy wants to discover new things that everyone likes.
Fluffy likes to watch spaceship guns in Golly.

There’s one problem,

Fluffy doesn’t exist :(

Redstoneboi

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Joined: May 14th, 2018, 3:57 am

### Re: Thread for basic questions

Redstoneboi wrote:
Apple Bottom wrote:
KittyTac wrote:What would be the best way for it to defend against switch engines and gliders flying in its direction? Building walls? Shooting *WSSs in random directions?

Building IceNine, clearly.

I know this is a joke, but building IceNine would just be a suicide bombing.

Unless it is built in such a way that it grows away from the AI core. If Ice-Nine is basically a spacefiller that has a clear "growing part" and a clear "stable part" that can survive without the growing part, then it is possible to make it not grow in all directions, making an indestructible barrier.

KittyTac

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### Re: Thread for basic questions

Have any irrational-speed spaceships been constructed?
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gameoflifemaniac

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### Re: Thread for basic questions

gameoflifemaniac wrote:Have any irrational-speed spaceships been constructed?

I don't quite think so, but it doesn't seem that hard considering how awesome technology is nowadays...a spaceship that computes the digits of pi using a computer, and replicates itself n units away, where n is the next digit of pi, would be irrationally speeded...sped? spode? i don't know.

EDIT: By the way, interesting question!
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danny

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### Re: Thread for basic questions

danny wrote:
gameoflifemaniac wrote:Have any irrational-speed spaceships been constructed?

I don't quite think so, but it doesn't seem that hard considering how awesome technology is nowadays...a spaceship that computes the digits of pi using a computer, and replicates itself n units away, where n is the next digit of pi, would be irrationally speeded...sped? spode? i don't know.

EDIT: By the way, interesting question!

There's a technical flaw in your design: a pi-calculating spaceship wouldn't actually be a spaceship. A spaceship returns to its exact initial configuration after T ticks, at an offset of (X, Y). T, X, and Y are all necessarily integers, so therefore there isn't any such thing as an irrational-speed spaceship.

We can certainly have irrational-speed universal constructors. They just won't quite be spaceships, because they have to store some information about how many digits of pi they've already calculated (or whatever equivalent calculation they're doing to get an irrational speed).

That prevents an irrational-speed UC from ever returning to its exact initial configuration. If it ever did that, it would inevitably start its calculation over again and "go rational", with that period and offset.

dvgrn
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### Re: Thread for basic questions

If we wanted to make an irrational speed "spaceship" that actually grew slightly each period, what's the slowest growth rate it could have? Is it log(t)?

Macbi

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### Re: Thread for basic questions

Macbi wrote:If we wanted to make an irrational speed "spaceship" that actually grew slightly each period, what's the slowest growth rate it could have? Is it log(t)?

I would think you could manage O(sqrt(log(t)) just by putting something like calcyman's Osqrtlogt counting pattern on a moving platform. Each "spaceship" would copy its data bank to a nearby location, add one to that copied value, then decrement the counter until it hits zero, send a signal to start up the child copy, then self-destruct.

(Would that work? I'm not always very good at this stuff.)

dvgrn
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### Re: Thread for basic questions

gameoflifemaniac wrote:Have any irrational-speed spaceships been constructed?

Yes, if you include the Penrose tiling gliders by Imai and me..
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calcyman

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### Re: Thread for basic questions

calcyman wrote:
gameoflifemaniac wrote:Have any irrational-speed spaceships been constructed?

Yes, if you include the Penrose tiling gliders by Imai and me..

Ooh, that's a really good answer. I'd forgotten about those Penrose-tile gliders.

I wonder if something similar could be found that would run on an Amman's A2 tiling -- maybe instead of following bow-ties, it could follow the spiral out from the center of inflation of an infinite tiling starting from a single tile.

Even if it just traveled straight across the tiling, an A2-tiling glider might count as irrational speed, just because of the irrational ratio between tile sizes. Not quite sure about that, though, since at the lowest level the tiling can be approximated by a square grid with a subset of the neighbor connections suppressed.

dvgrn
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### Re: Thread for basic questions

Penrose-tiling gliders?

KittyTac

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### Re: Thread for basic questions

calcyman wrote:Yes, if you include the Penrose tiling gliders by Imai and me...

But have any von Neumann neighborhood irrational speed spaceships been constructed which are aperiodic?
danny wrote:
gameoflifemaniac wrote:Have any irrational-speed spaceships been constructed?

I don't quite think so, but it doesn't seem that hard considering how awesome technology is nowadays...a spaceship that computes the digits of pi using a computer, and replicates itself n units away, where n is the next digit of pi, would be irrationally speeded...sped? spode? i don't know.

EDIT: By the way, interesting question!

Speeded.
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gameoflifemaniac

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### Re: Thread for basic questions

I'm fairly though not completely sure it would only be possible to have irrational-speed ships in aperiodic tilings like the Penrose tiling; the von Neumann neighbourhood, like the Moore neighbourhood, uses a simple square grid which is periodic, so it couldn't support such ships.

77topaz

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### Re: Thread for basic questions

Can I have a link to the Penrose tiling gliders?

KittyTac

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### Re: Thread for basic questions

77topaz wrote:I'm fairly though not completely sure it would only be possible to have irrational-speed ships in aperiodic tilings like the Penrose tiling; the von Neumann neighbourhood, like the Moore neighbourhood, uses a simple square grid which is periodic, so it couldn't support such ships.

I wrote:which are aperiodic
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gameoflifemaniac

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### Re: Thread for basic questions

Does anyone know why afind sometimes has random segmentation faults? I don't know if anyone even uses afind, but sometimes it suddenly stops with a segmentation fault error for an unknown reason.
Things to work on:
- Find a (7,1)c/8 ship in a Non-totalistic rule (someone please search the rules)
- Find a C/10 in JustFriends
- Find a C/10 in Day and Night
AforAmpere

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### Re: Thread for basic questions

KittyTac wrote:Can I have a link to the Penrose tiling gliders?

https://www.newscientist.com/article/dn ... -universe/

EDIT: segfaults are often caused by trying to allocate too much memory on the stack, e.g. by declaring a large array instead of mallocking it.
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calcyman

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### Re: Thread for basic questions

calcyman wrote:
gameoflifemaniac wrote:Have any irrational-speed spaceships been constructed?

Yes, if you include the Penrose tiling gliders by Imai and me..

What is the Penrose tiling gliders rule?

wwei23

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### Re: Thread for basic questions

wwei23 wrote:What is the Penrose tiling gliders rule?

Download Ready from https://github.com/GollyGang/ready and click on Goucher_glider.vtu or Imai_glider_B2SC4.vtu in Patterns/CellularAutomata/PenroseTiling. The Kernel box in the right Info pane shows the rule (OpenCL code).

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