Can we substantiate this claim?

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dbell
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Re: Can we substantiate this claim?

Post by dbell » June 9th, 2022, 9:16 pm

Here is the unusual spaceship used in the fly-by deletion of a pond.

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x = 89, y = 53
#C A fly-by deletion of a pond using an unusual spaceship.
#C From a collection by Jason Summers in 2001.
23boo16bo5bo18bo5bo5bo$22bobbo14b3o3b3o7b3o6b3o3b3o3b3o$22bobbo14boboo
boobbo5bobbo6bobooboobbobobboo5bo$23boo6bo9bobo4b3o3b3obbo6bobobobboob
obboo4b3o$30b3o8b3obobobo8b6obbo3bobobobobbo5boboo$bo15bo11bobboo3b8ob
5obobbo4bobo3b3o5b3o3bo5b3o$3o6bo6b3o10bobboo3boboobbo5bobobbo9bo4boob
o7bo5b3o$oboo4b3o5boboo11bobbobbobo4bobbo15bo7bo8b4obboo$b3o3bobboo5b
3o7bo3bobbo9boo30bo3bo$b3obbobobbo5b3o11b4o$boo7bob3obboo12booboo$4boo
6boo3boo14bobbo$bbobbo6bo3boo12bobbobbob3o$bo11bo17bo6boboo$bo35bobbob
oo$40bobo$19bo12bo6booboboo$18b3o10b3o8boboo$18boboo8boobo8bobbo$19b3o
8b3o9booboo$19b3o8b3o6booboobbo$19b3o9boo8boobbobo$19boo20boo$$42bobo$
17bo23bob3o$16b3o21boobobbo$15boobo20bobo$15b3o21bo5bo$15b3o20bo4bobo$
16boo19boo4bobo$37boo$38bobbo$$38b3o$37bobbo$37b5o$37boo$38boobbo$39bo
5bo$38bo5b3o$37boo5boboo$38bo6b3o$38bo6boo$39boboo$40b3o$$43bo$44bo$
44boo$44b3o$44b3o$44boo!
A smaller spaceship with the same sparks can probably be found.

BCNU,
-dbell

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GUYTU6J
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Re: Can we substantiate this claim?

Post by GUYTU6J » June 11th, 2022, 8:06 am

dbell wrote:
June 9th, 2022, 9:16 pm
Here is the unusual spaceship used in the fly-by deletion of a pond.

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A 2c/4 behemoth
Does it mean when the Life Lexicon/LifeWiki entries for Fly-by deletion and Reanimation were written, the circumstance allowed period-4 spaceships only (and no higher periods like p32 mentioned here)?

---

In Rephaser, Entity Valkyrie wrote:
For example, two bumpers in a 180-degree turn can be used as a rephaser to get a glider stream of repeat time 52 to the same place that two Snarks could, but arriving at a time impossible to do with the Snark.
Why period 52? That is apparently higher than the repeat time of both Snark and bumper. There must be some omitted context for the statement.
Why do most natural OCA rules tend to get a diminishing span of interest and go into oblivion, like a lost civilization leaving little records for its beauty and power?

I have been focusing on this rule, now in industrial era:

熠熠种花 - Glimmering Garden

Book
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Re: Can we substantiate this claim?

Post by Book » June 18th, 2022, 8:14 pm

This from the Wire article:
Oscillators have been found that inject signals of various periods including 9, 10, and 11 into a 5c/9 wire.[citation needed]
Can we substantiate?

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dvgrn
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Re: Can we substantiate this claim?

Post by dvgrn » June 18th, 2022, 9:31 pm

Book wrote:
June 18th, 2022, 8:14 pm
This from the Wire article:
Oscillators have been found that inject signals of various periods including 9, 10, and 11 into a 5c/9 wire.[citation needed]
Can we substantiate?
Sure, that's all in Dean Hickerson's signal-injector collection, I believe.

carsoncheng
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Re: Can we substantiate this claim?

Post by carsoncheng » June 22nd, 2022, 9:20 am

In the wiki article for 144P24, one unreferenced statement is present without any references or associated RLE.
"the stable form of the crown wasn't found until two months later"

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pzq_alex
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Re: Can we substantiate this claim?

Post by pzq_alex » June 22nd, 2022, 12:06 pm

carsoncheng wrote:
June 22nd, 2022, 9:20 am
In the wiki article for 144P24, one unreferenced statement is present without any references or associated RLE.
"the stable form of the crown wasn't found until two months later"
crown lists the discovery date as Jan 3, 1995, while the discovery date of 144P24 is Nov 20, 1994.
Make b38s23/C1 great again!
https://catagolue.hatsya.com/census/b3a ... a4ity6c/C1
救救kench
Working on a spaceship search program…
Stop turning this forum into a place for politics. Please.

Code: Select all

x=4,y=3,rule=B3S2-i3-a4ciz5j6c8
bo$3o$ob2o!

HartmutHolzwart
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Re: Can we substantiate this claim?

Post by HartmutHolzwart » June 23rd, 2022, 1:58 am

On an upper bound for the average density of periodic agars for period n, here's two mails from the life list:
-4399 From: Hartmut Holzwart
Date: Fri, 18 Sep 92 15:37:20 +0200
Subject: Re: density of successive generations of life


In a recent message Dean gave a proof that the average density of two
successive generations in the game of life is at most 6/11 and
conjectured that the possible pairs of densities (d,e) lie in the
convex hull of the points (0,0), (1,0) and (1/3,1).
I briefly summarize and rephrase the important part of his proof:
Denote by l_i and d_i the number of living
respectively dead cells with i ON neighbors in generation 0. Then there are
8*l_0 + 7*l_1 + ... + l_7 = d_1 + 2*d_2 + ... + 8*d_8 (*)
pairs of cells containing one ON and one OFF cell.
Now the number of living cells in gen. 0 is l_0 + ... + l_8, while the
number of living cells in gen. 1 is l_2 + l_3 + d_3. From equation (*)
we get 3*d_3 <= 8*(l_0 + l_1 + l_4 + ... + l_8) + 6*(l_2 + l_3) and
thus
l_2 + l_3 + d_3 <= 8/3*(l_0 + ... + l_8) + 3*(l_2 + l3)
<= 3*(l_0 + l_1 + ... + l_8) (No subscript omitted).
Using Deans notation, this means e <= 3*d.
On the other hand we can forget about part of the lefthand side and
get
5*(l_2 + l_3) <= 8*(d_0 + d_1 + d_2 + d_4 + ... + d_8) + 3*d_d_3
that is
5*(l_2 + l_3 + d_3) <= 8*(d_0 + ... + d_8). In Dean's notation, this
is
5*e <= 8*(1-d).
While equality in the first case can easily be achieved, this is not
so for the second case. This is because the proof uses only the fact
that the edge degree of the underlying graph is 8. Then our problem
can be restated as a problem of coloring graphs. one can easily
construct an infinite graph, that has edge degree 8 and admits a
coloring such that equality in the second case is reached. Thus no
improvement can be made by this 'local' method.
To prove Dean's conjecture, one has to take into account 'global'
effects.

Has anyone the right idea where to begin with that?

Hartmut
And a little later with a slightly confusing switch of notation:
-4426 From: Hartmut Holzwart
Date: Fri, 11 Sep 92 17:59:22 +0200
Subject: Infinite p2 with density 1/2


To John: The argument is really simple. Dean had an inequality that
can be written 8d_i+5d_(i+1)<=8, where d_i is the density of the i-th
generation. Adding up all these inequalities and using d_(n+1)=d_1 (typo corrected) for
period n things gives 13*(d_1+...+d_n)<=8*n and this is the result. Do
you see any flaw in that argument?

Hartmut
I hope I cited everything correctly. The second mail was an answer on a question by JHC...

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