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Talk:Apollonian gasket

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to construct the whole gasket. And if any four mutually tangent circles in the gasket have integer curvatures, then all circles in the gasket will have integer curvatures. We can characterise each gasket by giving the curvature of the outermost circle (this will be negative) and the curvatures of the
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To obtain an integer packing one needs four integer curvatures that satisfy DCE, not just three. The first three in the tables happen to produce the fourth, but how were these first 3 obtained to begin with? Are all possible packings accounted for? Also, DCE solutions yield the same packing as .
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Thanks for that, Gandalf61. My guess is that all possible packings could also be accounted for by proceeding in some fashion from the simplest packing and reflecting each curvature in turn. Perhaps a tree structure is the result? On the Hausdorff dimension calculation can you say what values for
1502:? The figure shown in the article is similar to the one shown on the Ford Circle page, but has more circles and is, I think, more clear. If there are no objections, I will (eventually) create the picture and add a description somewhere in the section on integral packings. 1173: 748:. To avoid this, it would help if you gave more references that discuss integer gaskets - the Lagarias, Mallows and Wilks paper that you reference is about extensions of Descartes' circle theorem, and only mentions integer gaskets in passing. 900: 1537:"(in the general construction, these three circles have to be different sizes, and they must have a common tangent)" I'm not an expert, but shouldn't that be "three circles may be different sizes" ? 1250: 988: 725: 581: 337:" or some such, relating circle sizes using integers? A very short google showed articles at mathworld, but no mention of integers ... maybe I'm imagining the bit about integers?? 524: 473: 366:
I added a huge section on Integral Apollonian Circle Packing, and included the reference for what you are thinking about. Feedback on the section is appreciated.
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in order to make clear exactly which are the 4th & 5th circles. As a clueless non-editor, I don't dare attempt such a potentially space-disrupting change.
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but I couldn't add the link to the External Links section due to potential conflict of interest. Can someone review it and add if appropriate? Thanks!
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I'd love to see this article worked in with a nicely-explained example: The Local-Global Conjecture for Apollonian circle packings is false
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How does one move from the one characterization to the other? This could be explained a little better. Otherwise, very nice article.
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any topic like this just cries out for illustrations so us folks that aren't so hot at math can understand what's being discussed.
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If we know the curvatures of any three mutually tangent circles in an Apollonian gasket then we can use repeated applications of
1168:{\displaystyle k_{4}=k_{1}+k_{2}+k_{3}\pm 2{\sqrt {k_{1}k_{2}+k_{2}k_{3}+k_{3}k_{1}}}=2+3+6\pm 2{\sqrt {36}}=-1{\text{ or }}23} 1200: 172: 133: 1479: 1384: 108: 936:. Furthermore, if we require the next circle (and hence the whole gasket) to have an integer curvature also, then 684: 983:
To answer your second question, and generate the same gasket because, applying Descartes' theorem to , we have
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to delete these "External links modified" talk page sections if they want to de-clutter talk pages, but see the
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The problem remains that there is currently no diagram accompanying the text that identifies C1, C2, C3, etc.
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are also integers, and it then follows that all the circles in the gasket will have integer curvature.
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https://web.archive.org/web/20060914030236/http://local.wasp.uwa.edu.au/~pbourke/papers/apollony/
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before doing mass systematic removals. This message is updated dynamically through the template
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https://www.quantamagazine.org/two-students-unravel-a-widely-believed-math-conjecture-20230810/
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is a square number. This gives us a way of systematically generating all integer gaskets. I
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I'm surprised not to see a picture of the special case (0,0,1,1), and it's relationship to
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to be integers, then there are a finite number of possibile triplets for each value of
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If you found an error with any archives or the URLs themselves, you can fix them with
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https://web.archive.org/web/20110502081052/http://closet.zao.se:80/emilk/circles.html
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is the curvature of the bounding circle) then the curvatures of the next two circles
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two largest circles inside the gasket - so we have a triplet where 0 <
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Add: The Local-Global Conjecture for Apollonian circle packings is false
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https://commons.m.wikimedia.org/File:Apollonian_gasket_construction.svg
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Article should explain from the start that C1, C2, C3 can be any size
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It is possible that someone might suggest that this new section is
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Each gasket is completely described by the curvatures of its first
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column on 11 October 2004. The text of the entry was as follows:
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I have now made changes in the article to correct these errors.
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When you have finished reviewing my changes, please set the
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yeah, this page def needs a pic, or at least a link to one.
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for additional information. I made the following changes:
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http://www.math.ucsd.edu/~ronspubs/03_02_appolonian.pdf
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http://local.wasp.uwa.edu.au/~pbourke/papers/apollony/
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Hi. Can apollonian gaskets be divided in types like :
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Special case (0,0,1,1) and reference to Ford Circles
1431:using the archive tool instructions below. Editors 952:we can test the finite number of possibilities for 1244: 1167: 894: 719: 575: 518: 467: 388:is interesting - well done. A few corrections: 1417:This message was posted before February 2018. 948:must be a square number. So for each value of 655:There are definitely no integer gaskets with D 277:I think the page needs the construction image 1319:http://www.jasondavies.com/apollonian-gasket/ 720:{\displaystyle {\frac {a}{b}}=2{\sqrt {3}}-3} 8: 1317:I created an interactive JavaScript demo at 976:the list in the article is exhaustive up to 395:circles. not four. If these curvatures are - 176:, which collaborates on articles related to 1197:N,S one should use in the this equation? 576:{\displaystyle \Delta ={\sqrt {bc-ab-ac}}} 122: 1357:I have just modified 2 external links on 1210: 1202: 1157: 1141: 1109: 1099: 1086: 1076: 1063: 1053: 1047: 1035: 1022: 1009: 996: 990: 875: 853: 704: 688: 686: 545: 537: 481: 430: 1389:http://closet.zao.se/emilk/circles.html 124: 94: 73:Knowledge:Recent additions/2004/October 264:The image was added 22:06, 8 Oct 2004 1406:to let others know (documentation at 71:A record of the entry may be seen at 7: 232:This article is within the field of 170:This article is within the scope of 113:It is of interest to the following 916:, there is also an upper limit on 539: 513: 462: 386:Integral Apollonian Circle Packing 14: 1361:. Please take a moment to review 838:, we can place an upper limit on 519:{\displaystyle e=-a+b+c+2\Delta } 468:{\displaystyle d=-a+b+c-2\Delta } 79: 1600:Systems articles in chaos theory 157: 147: 126: 95: 19: 1595:Mid-importance Systems articles 1585:Knowledge Did you know articles 210:This article has been rated as 644:, which means that Δ=0 and so 620:the only integer gasket with D 1: 360:22:30, 21 February 2008 (UTC) 342:02:16, 11 November 2005 (UTC) 190:Knowledge:WikiProject Systems 1605:WikiProject Systems articles 1547:13:41, 3 December 2020 (UTC) 1512:19:53, 22 January 2018 (UTC) 1485:12:38, 16 October 2016 (UTC) 193:Template:WikiProject Systems 1571:20:53, 12 August 2023 (UTC) 1331:13:42, 16 August 2010 (UTC) 1313:Interactive JavaScript demo 291:04:24, 13 August 2015 (UTC) 1621: 1448:(last update: 5 June 2024) 1354:Hello fellow Wikipedians, 1345:02:14, 6 August 2014 (UTC) 308:09:17, Oct 11, 2004 (UTC) 216:project's importance scale 1527:16:47, 28 June 2018 (UTC) 1308:18:37, 17 July 2010 (UTC) 780:14:17, 9 March 2008 (UTC) 758:16:07, 1 March 2008 (UTC) 376:01:31, 1 March 2008 (UTC) 329:Descartes circle theorem? 231: 209: 142: 121: 1590:B-Class Systems articles 1268:05:19, 8 July 2010 (UTC) 1188:13:11, 2 July 2010 (UTC) 960:to find those for which 811:15:17, 1 July 2010 (UTC) 739:cannot both be integers. 603:and Δ are integers then 335:Descartes circle theorem 321:23:36, 6 July 2010 (UTC) 274:18:11, 9 Oct 2004 (UTC) 30:appeared on Knowledge's 1350:External links modified 64:, any two of which are 1517:I have done this now. 1246: 1169: 896: 721: 663:symmetry we must have 628:symmetry we must have 577: 520: 469: 228: 165:Systems science portal 103:This article is rated 84: 1247: 1170: 897: 722: 578: 521: 470: 227: 82: 60:generated from three 1533:General construction 1429:regular verification 1201: 989: 852: 685: 536: 480: 429: 1419:After February 2018 1398:parameter below to 1335:|very nice effort! 920:. So if we require 659:symmetry. To have D 624:symmetry. 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