3 ms·

What does "elementary" mean in this context?

vanderZwan 9y ago
tantalor is correct. If you look on the knightship[0] page links a non-elementary ship: the Waterbear[1][2]. It is essentially a circuit built out of gliders, rather than a compact mass. [0] http://conwaylife.com/wiki/Knightship http://conwaylife.com/wiki/Knightship [1] http://conwaylife.com/wiki/Waterbear http://conwaylife.com/wiki/Waterbear [2] https://www.youtube.com/watch?v=on3ZLLKQp-4 https://www.youtube.com/watch?v=on3ZLLKQp-4
- bringtheaction 9y ago
  That waterbear looks very complex. How did they ever manage to find it?
  - vanderZwan 9y ago
    I'm not a part of the subculture, but every time I go down the rabbit hole of the discussion boards I get the impression it's one with crazy levels of dedication, and one that draws very particular kind of mathematics & programmer types of minds (honestly, it's a lot of fun to see them geek out over it every time I do, even if I can't follow 90% of what they're saying). So my best guess is: a mixture of mathematics, brute force searching, and lots of passionate on-line discussion with fellow nerds.
  - Maybestring 9y ago
    Its software built up from useful abstract blocks. Small parts like generators, gliders and eaters are used to build an information storage tape, and a tape fed universal constructor. From there it's the "simple" process of designing a tape and constructor setup that will build a copy of itself at a certain offset, and delete itself upon completion.
    - dvgrn 9y ago
      The part above about "tape and constructor" is exactly right for the self-constructing Gemini spaceship and its descendants. But it's not quite right for the waterbear. There's no universal constructor in the waterbear, or in its relatives the Centipede and the original Caterpillar. Large parts of these macro-spaceships never get constructed or destroyed, they just travel along a support structure. That support structure is the only thing that gets constructed, and the construction recipe is encoded not in a simple "tape" glider stream but in the entire body of the spaceship. Self-supporting spaceships like the waterbear are built with a very limited "toolkit" that only works at one particular speed. In general they're harder to put together successfully, and thus in a way are more impressive than self-constructing spaceships. Once you have a universal constructor, after all, you can build anything that's buildable. The trick is figuring out how to get along without that much power.
  - invisibowl 9y ago
    It wasn't "found", rather built from smaller components (that were found, of course, and by various computer-aided search techniques plus manual finagling). Its final assembler released a decently-quick rundown in the form of a video recording: https://www.youtube.com/watch?v=on3ZLLKQp-4 https://www.youtube.com/watch?v=on3ZLLKQp-4
- joebergeron 9y ago
  Is there a more compact or well-defined way to phrase this? Does "elementary" mean that by removing any arbitrary n cells, this structure won't exhibit the intended behavior? Or it won't exhibit any "interesting" behavior at all? Or does it mean that no subset of the cells exhibit any interesting behavior on their own?
  - Miredly 9y ago
    From the looks of it, no actual subset of it would form a functional system, so it is itself a fundamental unit?
    - dvgrn 9y ago
      That's basically right. Remove any one cell or any subgroup from the knightship, and it's no longer a working spaceship -- at least not one that moves the same speed! There are "optional extras" that can be added or removed from some spaceships. These are called "tagalongs", and aren't considered to be part of the ship. That can get a little complicated, too, though, like with another recent-ish discovery: http://conwaylife.com/wiki/Fireship http://conwaylife.com/wiki/Fireship .
tantalor 9y ago
I think it means self-contained, that is, not "built up" from other things colliding and interacting. http://conwaylife.com/wiki/Elementary http://conwaylife.com/wiki/Elementary
- deleted 9y ago
  [deleted]
ouid 9y ago
from what I can gather from the answers given here, it means "doesn't contain any gliders"

tantalor is correct. If you look on the knightship[0] page links a non-elementary ship: the Waterbear[1][2]. It is essentially a circuit built out of gliders, rather than a compact mass. [0] http://conwaylife.com/wiki/Knightship http://conwaylife.com/wiki/Knightship [1] http://conwaylife.com/wiki/Waterbear http://conwaylife.com/wiki/Waterbear [2] https://www.youtube.com/watch?v=on3ZLLKQp-4 https://www.youtube.com/watch?v=on3ZLLKQp-4

bringtheaction 9y ago
That waterbear looks very complex. How did they ever manage to find it?
- vanderZwan 9y ago
  I'm not a part of the subculture, but every time I go down the rabbit hole of the discussion boards I get the impression it's one with crazy levels of dedication, and one that draws very particular kind of mathematics & programmer types of minds (honestly, it's a lot of fun to see them geek out over it every time I do, even if I can't follow 90% of what they're saying). So my best guess is: a mixture of mathematics, brute force searching, and lots of passionate on-line discussion with fellow nerds.
- Maybestring 9y ago
  Its software built up from useful abstract blocks. Small parts like generators, gliders and eaters are used to build an information storage tape, and a tape fed universal constructor. From there it's the "simple" process of designing a tape and constructor setup that will build a copy of itself at a certain offset, and delete itself upon completion.
  - dvgrn 9y ago
    The part above about "tape and constructor" is exactly right for the self-constructing Gemini spaceship and its descendants. But it's not quite right for the waterbear. There's no universal constructor in the waterbear, or in its relatives the Centipede and the original Caterpillar. Large parts of these macro-spaceships never get constructed or destroyed, they just travel along a support structure. That support structure is the only thing that gets constructed, and the construction recipe is encoded not in a simple "tape" glider stream but in the entire body of the spaceship. Self-supporting spaceships like the waterbear are built with a very limited "toolkit" that only works at one particular speed. In general they're harder to put together successfully, and thus in a way are more impressive than self-constructing spaceships. Once you have a universal constructor, after all, you can build anything that's buildable. The trick is figuring out how to get along without that much power.
- invisibowl 9y ago
  It wasn't "found", rather built from smaller components (that were found, of course, and by various computer-aided search techniques plus manual finagling). Its final assembler released a decently-quick rundown in the form of a video recording: https://www.youtube.com/watch?v=on3ZLLKQp-4 https://www.youtube.com/watch?v=on3ZLLKQp-4
joebergeron 9y ago
Is there a more compact or well-defined way to phrase this? Does "elementary" mean that by removing any arbitrary n cells, this structure won't exhibit the intended behavior? Or it won't exhibit any "interesting" behavior at all? Or does it mean that no subset of the cells exhibit any interesting behavior on their own?
- Miredly 9y ago
  From the looks of it, no actual subset of it would form a functional system, so it is itself a fundamental unit?
  - dvgrn 9y ago
    That's basically right. Remove any one cell or any subgroup from the knightship, and it's no longer a working spaceship -- at least not one that moves the same speed! There are "optional extras" that can be added or removed from some spaceships. These are called "tagalongs", and aren't considered to be part of the ship. That can get a little complicated, too, though, like with another recent-ish discovery: http://conwaylife.com/wiki/Fireship http://conwaylife.com/wiki/Fireship .

tantalor 9y ago

I think it means self-contained, that is, not "built up" from other things colliding and interacting. http://conwaylife.com/wiki/Elementary http://conwaylife.com/wiki/Elementary

deleted 9y ago
[deleted]

ouid 9y ago

from what I can gather from the answers given here, it means "doesn't contain any gliders"