Timeline for Solving the unknotting problem by pulling both ends of the string
Current License: CC BY-SA 4.0
17 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Mar 14 at 15:58 | comment | added | Sam Nead | Negative results are still results! Good luck on your journey. :) | |
| Mar 14 at 11:30 | comment | added | Craig Feinstein | If you read my update, my proposal did not work. | |
| Mar 13 at 18:06 | comment | added | Craig Feinstein | My experience is that with magician’s rope, my proposal would probably work. It is both flexible and sturdy. I will try it out on the hard unknots that were listed in the links you gave. | |
| Mar 13 at 16:11 | comment | added | Craig Feinstein | yes thank you very much for your help and the link. I am new to the subject matter of knots, except for my experience with them in magic. | |
| Mar 13 at 16:07 | vote | accept | Craig Feinstein | ||
| Mar 13 at 13:55 | comment | added | Sam Nead | In any case, it seems that you found the references I provided of some interest. If that is the case, you might consider accepting my answer to your question. (And then thinking a bit, and then asking another question. :) | |
| Mar 13 at 13:54 | comment | added | Sam Nead | You may be interested in the discussion of physical knots between Tim Gowers and Bill Thurston here: mathoverflow.net/questions/53471/… - in particular they end by agreeing that there are "tangled marionettes" that are very hard to untangle. I regard this as evidence against the claim that "in real life, it is not so difficult to recognize an unknot". | |
| Mar 13 at 12:17 | comment | added | Craig Feinstein | All I am saying is that in real life, it is not so difficult to recognize an unknot. Thus, if a computer simulates real life, it shouldn’t be so difficult to recognize an unknot on a computer. | |
| Mar 13 at 11:50 | comment | added | Craig Feinstein | your assessment is correct, but I don’t think this is a bad thing. This is how problems get solved. | |
| Mar 13 at 8:05 | comment | added | Sam Nead | Instead I am saying that all people have emotional attachment to their positions, which makes it hard to understand other people’s attitudes and backgrounds. | |
| Mar 13 at 8:05 | comment | added | Sam Nead | Your argument is an “intuition pump”- en.wikipedia.org/wiki/Intuition_pump - which is then followed by a “bait and switch” - rationalwiki.org/wiki/Bait-and-switch - … To clarify - I am not suggesting that you are arguing in bad faith… | |
| Mar 12 at 23:29 | comment | added | Craig Feinstein | if the problem is the length of sticks as shown in the first paper (or even the width of the sticks), whenever the algorithm runs into this issue, it could bypass it by making the sticks longer and thinner or add breakpoints if that doesn’t work. If it continues to do this, it will get the string unknotted. And probably polynomial time too since this little adjustment shouldn’t take too long. | |
| Mar 12 at 22:42 | comment | added | Sam Nead | Your question said "since in real life it is quick, at least in my experience". These papers are pointing out that physical experience may be misleading you. Your comment is saying that these counterexamples "might be problematic in the physical world but not in the virtual world". But you've not given me any hints of how you wish to proceed in the virtual world... so how can I evaluate your plan to recognise the unknot? | |
| Mar 12 at 22:34 | comment | added | Craig Feinstein | These papers give problems that such an algorithm may encounter (unknots that cannot be unknotted) but also give solutions on a computer (change the lengths of the sticks so they can be unknotted). They might be problematic in the physical world but not in the virtual world. | |
| S Mar 12 at 21:36 | history | suggested | The Amplitwist | CC BY-SA 4.0 |
added DOI links and full citations in tooltips
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| Mar 12 at 19:57 | review | Suggested edits | |||
| S Mar 12 at 21:36 | |||||
| Mar 12 at 19:05 | history | answered | Sam Nead | CC BY-SA 4.0 |