A question that seems to be hard to say

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shuich01
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A question that seems to be hard to say

Post by shuich01 » May 19th, 2021, 6:16 am

Is there any unsimplified speed (x,y)c/p (2(|x|+|y|)<=p) that no spaceships exist?
Just for the life...

Dylan Chen
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Re: A question that seems to be hard to say

Post by Dylan Chen » May 19th, 2021, 7:41 am

Last edited by Dylan Chen on May 20th, 2021, 3:50 am, edited 1 time in total.
Tools should not be the limit.
Whether your obstacle is a script, an stdin, or Linux environment computing resouces.
check New rules thread for help.

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yujh
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Re: A question that seems to be hard to say

Post by yujh » May 19th, 2021, 8:41 am

? & still don’t understand the question.

Code: Select all

#N 77P6H1V1
#O Josh Ball
#C The smallest known c/6 diagonal spaceship; found in March, 2011
#C http://www.conwaylife.com/wiki/index.php?title=77P6H1V1
x = 36, y = 36, rule = b3/s23
34bob$33bobo$31b2o2bo2$30bo5b$27b2o2b2o3b$27b2o7b$27bo8b$25bobo8b$25b
2o9b$23bo2bo9b$22bo4bo8b$21bo5bo8b$18bo3bo13b$17bobo3b2o11b$16b2ob2o
15b$15b2o4bobo12b$14b2o7bo12b$13bo9bo12b$14b2o20b$15bo20b$12bo3bo19b$
11bobo22b$10bo3bob3o17b$14bo21b$8b2o26b$9b2o25b$5b4o2b2o23b$5b2o29b2$
4bo31b$2bo2bo30b$2bo2bo30b$bo34b$o35b$b2o!

pzq_alex
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Re: A question that seems to be hard to say

Post by pzq_alex » June 9th, 2021, 10:54 pm

Um... I'm not particularly well at engineering macro-spaceships, but there are a few things I can say.
  • Speed Demonoids allow every possible diagonal speed.
    Orthogonoids can also allow every possible orthogonal speed.
    For oblique speeds, a macro-spaceship can theoretically be built if there is an appropriate helix.
    Also, adjustable oblique spaceships might also allow every possible oblique speed -- I see no theoretical difficulties, and I believe that such a family of adjustable oblique ships will very probably exist, just that no-one has built it yet.
Help us investigate B3/S23-a6!

Code: Select all

x = 8, y = 12, rule = B3/S23-a6
2bo$b4o$o2b2o$b2obo2$4bo$3bo$2bobo$3bob2o$3bo3bo$3bo2bo$5bo!
viewtopic.php?f=11&t=5289&p=131603#p131603

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Moosey
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Re: A question that seems to be hard to say

Post by Moosey » June 10th, 2021, 5:42 pm

shuich01 wrote:
May 19th, 2021, 6:16 am
Is there any unsimplified speed (x,y)c/p (2(|x|+|y|)<=p) that no spaceships exist?
Well, we definitely don't know of ships at all speeds, particularly not unsimplified as you stated (this rules out the macro-spaceships mentioned in the above post); but a proof of the nonexistence of a spaceship at a specific unsimplifed speed with the conditions you stated would be highly nontrivial (unless you count (0,0)c/n, though if you consider that a valid velocity for spaceships then it seems strange to say that oscillators aren't spaceships because they're called something else :P ).

By the way, in the future you might want to ask similar questions in the dedicated thread.
My CA rules can be found here

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toroidalet
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Re: A question that seems to be hard to say

Post by toroidalet » June 10th, 2021, 6:32 pm

For all low periods that have been searched, long partial spaceships have been constructed, usually consisting of a working front end with a tail that rapidly degenerates (or sometimes a working tail with a head that rapidly degenerates), and there is no compelling reason why they should not be able to be completed. My personal opinion is that very large spaceships of all unsimplified speeds exist, but such a statement is nigh impossible to decide either way.
Moosey wrote:
June 10th, 2021, 5:42 pm
a proof of the nonexistence of a spaceship at a specific unsimplifed (sic) speed with the conditions you stated would be highly nontrivial
Indeed, there are rules where it is undecidable whether a spaceship of that unsimplified speed exists. (proof: have the top row be the starting configuration of a universal Turing machine with the numbers a and b written somehow; the top row moves up a cells then waits b generations and further rows move up whenever they have room, provided that they locally correspond to the evolution of the Turing machine) Needless to say, Life is probably not one of these rules, but the fact that these rules exist suggests that without explicitly coming up with a ship or showing that all branches of the search reach dead ends, it will be very hard to reason one way or another.
"But if you close your eyes—does it almost feel like nothing's changed at all?
And if you close your eyes—does it almost feel like you've been here before..."

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