Skip to main content
22 events
when toggle format what by license comment
Nov 9, 2010 at 1:10 history edited Mariano Suárez-Álvarez
edited tags
Nov 9, 2010 at 1:09 comment added Mariano Suárez-Álvarez Hmm. "integrable systems" has a technical meaning rather different from that. Retagging...
Nov 9, 2010 at 1:06 comment added Hans-Peter Stricker @Mariano: integrable = solvable = computable = decidable. If you find this tag inappropriate, please feel free to remove it.
Nov 9, 2010 at 0:59 comment added Mariano Suárez-Álvarez What is the connection to integrable systems?!
Nov 9, 2010 at 0:56 answer added Mariano Suárez-Álvarez timeline score: 5
Nov 9, 2010 at 0:49 vote accept Hans-Peter Stricker
Nov 9, 2010 at 0:41 comment added Hans-Peter Stricker @Steve: Thanks, that's enlightening. Have to think the Halting Problem over.
Nov 9, 2010 at 0:38 comment added Steve Richards @Hans: It depends on the interpretation. If $f$ is the halting state, then the problem is where $f$ will ever appear. So $f$ is the pattern. You can view words as multi-colored intervals. A move is a re-coloring of a certain small subinterval according to some finite collection of rules, and the problem is whether a certain color or combination of colors will ever appear. You can always assume that there are only two colors only. That's 1-dimensional "life".
Nov 9, 2010 at 0:28 comment added Hans-Peter Stricker @Steve: I would have guessed that the patterns of the Halting problem are 0-dimensional: "Stop and/or go".
Nov 9, 2010 at 0:24 comment added Steve Richards @Hans: Yes, that is what I meant. Halting problem is also about formation of pattern, only the patterns are 1-dimensional. I think the popularity of Convay's game is due to its name not due to its simplicity. If you call Turing machine "Life and/or death" machine, it would be much more popular too. :)
Nov 9, 2010 at 0:19 comment added Hans-Peter Stricker @Steve: Now I understand what you have meant: Conway's game is just another undecidable problem, not more relevant to "life" than the Halting problem. You may be right. Anyway: Conway's game concerns the formation of patterns in a very graspable sense.
Nov 9, 2010 at 0:14 comment added Hans-Peter Stricker @Peter: I have seen this, too. But it didn't give me a clue how to answer my question. (Please see my comment to sleepless in beantown's answer.)
Nov 9, 2010 at 0:05 answer added Alex B. timeline score: 8
Nov 9, 2010 at 0:03 comment added Steve Richards Halting problem, for example. Consider a sequence of substitutions $u_i\to v_i$, where $u_i, v_i$ are words. Start with a word $w$. Question: will a certain letter $f$ appear in any word obtained after a series of substitutions. There are very few substitution rules needed (three, I believe, perhaps even 2) to get undecidability.
Nov 9, 2010 at 0:02 answer added Peter Shor timeline score: 40
Nov 9, 2010 at 0:01 answer added sleepless in beantown timeline score: 8
Nov 8, 2010 at 23:54 comment added Hans-Peter Stricker But maybe you can give me a hint, where comparable questions have been answered already?
Nov 8, 2010 at 23:53 comment added Hans-Peter Stricker But I guess there won't be undecidable algorithmic problems that are considerably simpler than Conway's game.
Nov 8, 2010 at 23:50 comment added Steve Richards @Hans: The name "life" does not really mean it is a simulation of real life. Certainly there are undecidable algorithmic problems which are closer to real evolution than Conway's game.
Nov 8, 2010 at 23:47 comment added Hans-Peter Stricker Why "why"? It would be a clear-cut case, why the future - e.g. of evolution - cannot be foreseen in principle.
Nov 8, 2010 at 23:45 comment added Steve Richards That is probably true, but it is not clear how to prove it and why (it may require substantial effort).
Nov 8, 2010 at 23:40 history asked Hans-Peter Stricker CC BY-SA 2.5