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173:! I really appreciate you taking the time to do the review. Unfortunately, I've run out of time; I have to leave to help with my sister's wedding, and I can't follow up immediately on all of your suggestions. I'm leaving a few explanatory notes here, and hopefully someone else will be able to address your concerns. If not, I can always fix it once I return! Thanks again to everyone helping this little article, 695:
on historical context, personalities, applications. However, ultimately, the reader who wants to study the solution methods is going to have to concentrate, while other readers are more likely to prefer a separate discussion of history, people involved and relations to other mathematical ideas. I think this would result in a more encyclopedic approach and make the lead easier to write.
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As an aside, with an eye on the "comprehensiveness" criterion, surely someone must have studied the Apollonius problem over the complex numbers, where there should almost always be 8 solutions counted with multiplicity. The missing solutions in the real picture are actually complex conjugate. (Again,
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I agree with Ozob that one way to improve the balance of the article would be to provide a separate history section, and organise the solution methods by approach. I realise that this would destroy a nice feature of the current article: at present the technical methods material is broken up by asides
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I agree with Jakob that there is a mismatch between the emphasis of the lead and the emphasis of the article, and that both need fixing to bring the article into balance: the lead has too little on the solution methods, while the rest of the article has too little else. On the other hand, the length
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Many geometrical constructions such as bisecting an angle or a line segment can be done "by eye", or improved iteratively from an approximate solution. Apollonius' problem is more difficult in this respect; it is difficult to see "by eye" where to place the center of the solution circle or how large
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Figure 7 would benefit from showing the (constant) centers of the points. Perhaps move the captions somewhere else then? Its caption "The tangency of a set of circles is preserved if their radii are changed by the same amount" is not that clear. If you also draw two radii (whose sum is constant over
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I've tried to finesse this point, but I've taken the position most easily understood by non-mathematicians, that the C in CCC consist of circles that have finite, nonzero radius. Hence C≠P and C≠L. To help in understanding some of the other work, however, I want to open readers' minds to the idea
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the lead is pretty long, and seems to cover the article content in a slightly unbalanced manner: persons (and their names) take lots of space, but the actual solution methods only get one sentence "by a variety of geometric and algebraic methods, including transformations such as circle inversion",
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I suppose the relevant question for us to ask is, "What should this article be about?" It needs to tell the reader what the Problem of Apollonius is, why it's interesting, how to solve the problem, and what the history of the solutions is. "What", "why", and "history" are relatively short. "How" is
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Sadly, as Euclid pointed out, there are no royal roads to Geometry. Readers will be required to think here, and to read captions. If anyone could improve the image to make it more immediately intelligibl, I'd be grateful, but I did the best I could with the skills I have, and it seems adequate.
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Right now, "how" is broken up in two different ways: Either by solver (van Roomen, Viete, Gergonne) or by method (algebraic, inversion, Lie sphere). I think we need to pick one method of organization and stick with it. In my opinion that ought to be organization by method, because for a reader who
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Limiting cases: the definition of "limiting cases" seems a bit, erm, limiting. From the point of view of Moebius geometry (which is the natural symmetry of the problem), the degeneration of a circle to a line isn't really a limiting case; on the other hand the case that two or more of the initial
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It's helpful in some of the arguments below to know that solutions come in pairs. That's why it's introduced so early. It also warms the reader up for the inversive techniques later, so that they don't get hit with it all at once. I'd be open to moving it, but I did put some time and care into
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and a test-bed for many mathematical methods, particularly in 19th century with the resurgence of geometry. I've been working on it for roughly five months, and others have contributed significantly as well. Several daughter articles have been expanded, numerous figures and tables have been
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A general comment about the images: some are pretty complicated to digest on first sight (esp. the very first one) and hence have very lengthy captions. This suggests (to me) "separating" the images such that their meaning is conveyed in smaller steps. Also, it would be a plus if the three
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Hope this helps. Please note that I don't watchlist Peer Reviews I've done. If you have a question about something, you'll have to drop a note on my talk page to get my attention. (My watchlist is already WAY too long, adding peer reviews would make things much worse.) 15:25, 28 June 2008
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Intersecting hyperbolas: although this has been mentioned in the lead, the reader may be surprised to discover that "modern" here means 1596 (date from O'Connor and Robertson)! At some point, the reader needs to be reminded that "modern" means "post classical antiquity" in this
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Fabulous article! I read it thoroughly again yesterday morning bright and early (UTC) and I understood it! Given my username, this may seem unsurprising, but in fact I have great difficultly getting my mind around these (sometimes literally) baroque solution methods, and when I
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of the lead is fine for an article of this size; it seems longer than it is because of the long wide lead image. At this stage of development, I believe it is best to get the body of the article right first; with luck, the lead will then write (right?) itself :-).
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wants to know how to solve the problem, the method used is more relevant that who discovered the method. The history can be put in its own section. I also have the feeling that it might be a good idea to move some of this information to subarticles. For instance,
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That may result from the type of material being covered. I did try to cover aspects of the problem that aren't merely solution methods, e.g., discussing applications and placing it in a historical context, but the solution methods do form most of the story.
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Mutually tangent case: this is the first appearance of the signed radius issue (the radius and curvature can be negative). Also, is it relevant to say that Philip Beecroft was an amateur mathematician? The distinction is perhaps not so clear at this time in
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The special cases table 1 could perhaps be moved to the subpage? Also, do you count the CCC problem as the special case or as the general case? From a measure-theoretic point of view, CCC is the general case, but actually all cases show up under "special
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Anyway, this is peer review, so constructive criticism, not praise, is what editors are after, right? And since there is no obligation to follow my suggestions, and no icon to be awarded for success, I will be as critical and opinionated as I can be :-)
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Yes, I was concerned that the lead should convey the point of the problem clearly to non-mathematicians. But you're right, it does seem to give short shrift to the methods. Let me think about this, or others can take the plunge and do a re-write.
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a limiting case. Obviously we have to rely upon what the sources say here, but there surely must be sources which make this point. In terms of the algebra, the limiting cases are when some of the quadratic equations have repeated roots.
379:"they may even be points (circles of zero radius) or lines (circles of infinite radius)" - this may be distracting at this very early place. perhaps better in the paragraph "Apollonius' problem can be generalized in several ways ..." 331:
I changed it to "Each solution circle either contains or does not contain each given circle, and the eight solutions to Apollonius' problem correspond to the possible combinations of containment and non-containment (Figure 1)."
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My main problem: (but I don't know what to do about that): the article tends to be closer to a elementary geometry textbook section than to an encyclopedic article. (The applications section is a welcome exception to this
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Gergonne's solution: now that I finally understand it, I agree it is pretty elegant! However, a single 1929 textbook is probably not sufficient support for the assertion that it "is widely considered to be the most
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I agree with Jakob that more work is needed to make the article truly encyclopedic in style. In addition to the general issue of balance raised above (see the next point), there are also specific lapses, such as:
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It means "encircle/surround" versus exclude; the solution circle "includes" a given circle by surrounding it completely. It excludes it if the intersection of the two circles is the empty set.
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Algebraic solutions: I've attempted to clarify the signs issue. Also the fact that no configurations have 7 solutions needs a cite (I think you have one somewhere else, but don't remember).
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You said you wanted to know what to work on before taking to FAC, so I looked at the sourcing and referencing with that in mind. I reviewed the article's sources as I would at FAC.
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I think this is a nice article. It's very detailed. I have to confess that I didn't attempt to dive in the actual calculations and so on. So, here are some superficial thoughts:
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starting-circles would always have the same color in all images. Or use a dotted pen or something. Figure 2, e.g., is incredibly hard to figure out without reading the caption.
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I believe that it's known only from computations, not analytically. Conceivably, it might depend on the starting configuration of circles, too, although I guess not.
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I don't understand why the section "Pairs of solutions by inversion" is placed under statement and motivation. This seems to be part of the solution process, right?
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Typo fixed. When you say that it's not clear to you, do you mean that the sentence does not make sense, or that the figure does not seem to have this property?
705:", but then I saw the other reading as a long noun phrase. However, if I can be dogmatic for a moment (with a touch of Orwellian irony): long noun phrases bad. 663:
with the article, I found it hard going, the Gergonne solution especially. Much credit to the editors who have added so much detail and clarity since then.
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No, Steiner, Beecroft, Soddy, etc. just didn't do a very thorough literature search, apparently. They derived the same theorem independently of Descartes.
66: 613:"being self-similar and having a dimension d that is roughly 1.3" - is it known exactly? also, a word explaining fractal dimension would be good, I guess. 228: 103: 51: 220: 435:
I just realize that many images do use the same colors. So, forget this comment. But still, none of the images jumps into my mind effortlessly.
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People do keep removing my pixel counts but here goes again. I've enforced the scale to be 350px, which should be legible to most readers.
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The interest of this section is that it shows why the number of solutions is usually even. There may be a better location for it, though.
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It would be nice if non-English sources stated what language they were in, even the print ones. Not a requirement, just a nice gesture.
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I would especially appreciate any advice or insight on the accessibility of the article, and how to make it more suitable for FAC.
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Viète's reconstruction: the number of lemmas involved is not relevant in my view; the use of lemmas is a matter of convenience only.
856: 786: 278:"each of which include or exclude the given circles in diferent ways (Figure 1)" - this is not clear to me. (also a typo) 468:
Figure 1 would be clearer (I guess) if the circles would not be shaded, but just outlined. It looks very nice, though.
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Lie sphere geometry: the signed radius issue crops up again here, where it would be much nicer to allow the
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Solution methods: this first paragraph makes the case for a separate history section, in my view.
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More specific comments (please don't interleave replies here - I'll just get confused :)...
809: 625: 507: 416: 337: 290: 236: 845: 776: 476: 115: 99: 635: 596: 571: 545: 518: 480: 451: 387: 362: 318: 261: 201: 174: 130: 404:"Candidate transformations must one Apollonius problem into another" lacks a verb. 354:"This theorem was rediscovered three centuries later" - were they lost in between? 701:
First sentence: it reads two ways. At first I wanted to add a comma after "the
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that lines are circles of infinite radius, and points circles of zero radius.
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I've listed this article for peer review because I believe it to be ready for
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s to have a sign to make it more obvious that the "unusual product" is a
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time), the whole caption could be simplified and would be more intuitive.
118:. It covers an old but important problem in geometry, first solved by 721:
sources needed for that... although it is mentioned briefly later on.)
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I wanted to say that I don't understand the meaning of the sentence.
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Solutions to the problem of Apollonius using elementary geometry
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Solutions to the problem of Apollonius using circle inversion
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Statement: I reordered the first paragraph; is that clearer?
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The caption inside Fig 9 (esp. the indices) are very small.
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That's a very good idea. I'll try to work it in somehow.
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created, and the article has been referenced thoroughly.
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review of the article for issues relating to grammar and
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Solutions to the problem of Apollonius using algebra
570:That's a good idea, thank you! I'll work on that. 129:Thank you for your help in improving the article, 852:Peer review pages with semiautomated peer reviews 800:with the templates that start with Cite such as 252:which seems too little from a glance at the TOC 761:That's all folks! Thanks for your attention. 8: 111:This peer review discussion has been closed. 94:A script has been used to generate a semi- 712:circles (etc.) become tangent clearly 620:It doesn't seem to be known exactly. 7: 475:It's great, no? That's the work of 820:WP:Footnotes#Style recommendations 24: 808:. They shouldn't be mixed per 102:style; it can be found on the 1: 517:placing it where it is now. 873: 810:WP:CITE#Citation templates 104:automated peer review page 768:10:18, 28 June 2008 (UTC) 644:16:22, 27 June 2008 (UTC) 630:23:48, 26 June 2008 (UTC) 605:16:22, 27 June 2008 (UTC) 580:16:22, 27 June 2008 (UTC) 554:16:13, 27 June 2008 (UTC) 527:16:13, 27 June 2008 (UTC) 512:23:48, 26 June 2008 (UTC) 489:16:13, 27 June 2008 (UTC) 460:16:13, 27 June 2008 (UTC) 445:09:47, 27 June 2008 (UTC) 421:23:48, 26 June 2008 (UTC) 396:16:13, 27 June 2008 (UTC) 371:16:13, 27 June 2008 (UTC) 342:16:16, 27 June 2008 (UTC) 327:16:13, 27 June 2008 (UTC) 311:09:47, 27 June 2008 (UTC) 295:23:48, 26 June 2008 (UTC) 270:16:13, 27 June 2008 (UTC) 241:17:53, 27 June 2008 (UTC) 210:16:13, 27 June 2008 (UTC) 183:16:13, 27 June 2008 (UTC) 157:17:26, 26 June 2008 (UTC) 139:18:52, 24 June 2008 (UTC) 654:Comments by Geometry guy 796:You've mixed using the 749:symmetric bilinear form 857:July 2008 peer reviews 830:similar abbreviations. 802:Template:Cite journal 703:problem of Apollonius 28:Problem of Apollonius 18:Knowledge:Peer review 683:to make its radius. 120:Apollonius of Perga 806:Template:Cite news 689:According to whom? 798:Template:Citation 86:Watch peer review 864: 661:first interacted 83: 74: 55: 872: 871: 867: 866: 865: 863: 862: 861: 842: 841: 822:, we don't use 656: 437:Jakob.scholbach 303:Jakob.scholbach 149:Jakob.scholbach 89: 64: 41: 35: 31: 22: 21: 20: 12: 11: 5: 870: 868: 860: 859: 854: 844: 843: 840: 839: 834: 833: 832: 831: 816: 813: 759: 758: 757: 756: 752: 741: 738: 735: 731: 728: 724: 723: 722: 709: 706: 696: 692: 691: 690: 687: 686: 685: 673: 655: 652: 651: 650: 649: 648: 647: 646: 615: 614: 610: 609: 608: 607: 590: 589: 585: 584: 583: 582: 565: 564: 559: 558: 557: 556: 538: 537: 532: 531: 530: 529: 499: 498: 494: 493: 492: 491: 470: 469: 465: 464: 463: 462: 432: 431: 426: 425: 424: 423: 406: 405: 401: 400: 399: 398: 381: 380: 376: 375: 374: 373: 356: 355: 351: 350: 349: 348: 347: 346: 345: 344: 299: 298: 297: 280: 279: 275: 274: 273: 272: 254: 253: 248: 247: 246: 245: 244: 243: 216: 194: 193: 188: 187: 186: 185: 164: 163: 143: 113: 108: 107: 106:for June 2008. 91: 90: 88: 34: 30: 25: 23: 15: 14: 13: 10: 9: 6: 4: 3: 2: 869: 858: 855: 853: 850: 849: 847: 836: 835: 829: 825: 821: 817: 814: 811: 807: 803: 799: 795: 794: 792: 791: 790: 788: 785: 782: 778: 774: 770: 769: 766: 765: 753: 750: 746: 742: 739: 736: 732: 729: 725: 719: 718: 715: 710: 707: 704: 700: 699: 697: 693: 688: 684: 680: 679: 678: 677: 674: 670: 669: 668: 664: 662: 653: 645: 641: 637: 633: 632: 631: 627: 623: 619: 618: 617: 616: 612: 611: 606: 602: 598: 594: 593: 592: 591: 587: 586: 581: 577: 573: 569: 568: 567: 566: 561: 560: 555: 551: 547: 542: 541: 540: 539: 534: 533: 528: 524: 520: 515: 514: 513: 509: 505: 501: 500: 496: 495: 490: 486: 482: 478: 474: 473: 472: 471: 467: 466: 461: 457: 453: 448: 447: 446: 442: 438: 434: 433: 428: 427: 422: 418: 414: 411:I verbed it. 410: 409: 408: 407: 403: 402: 397: 393: 389: 385: 384: 383: 382: 378: 377: 372: 368: 364: 360: 359: 358: 357: 353: 352: 343: 339: 335: 330: 329: 328: 324: 320: 316: 315: 314: 313: 312: 308: 304: 300: 296: 292: 288: 284: 283: 282: 281: 277: 276: 271: 267: 263: 258: 257: 256: 255: 250: 249: 242: 238: 234: 230: 226: 222: 217: 213: 212: 211: 207: 203: 198: 197: 196: 195: 190: 189: 184: 180: 176: 172: 168: 167: 166: 165: 161: 160: 159: 158: 154: 150: 146: 141: 140: 136: 132: 127: 124: 121: 117: 112: 105: 101: 97: 93: 92: 87: 82: 81: 77: 72: 68: 63: 62: 58: 53: 49: 45: 40: 39: 33: 32: 29: 26: 19: 827: 823: 783: 772: 771: 764:Geometry guy 762: 760: 744: 713: 702: 681: 665: 657: 144: 142: 128: 125: 110: 109: 79: 75: 61:Article talk 60: 56: 37: 27: 215:quite long. 169:Thank you, 48:visual edit 846:Categories 755:elegant". 192:feeling). 96:automated 824:op. cit. 787:contribs 777:Ealdgyth 773:Comments 734:context. 727:history. 477:Melchoir 145:Comments 536:cases". 71:history 52:history 38:Article 636:Willow 597:Willow 572:Willow 546:Willow 519:Willow 481:Willow 452:Willow 388:Willow 363:Willow 319:Willow 262:Willow 227:, and 202:Willow 175:Willow 131:Willow 838:(UTC) 775:from 479:. :) 171:Jakob 100:house 80:Watch 16:< 828:ibid 818:Per 781:talk 640:talk 626:talk 622:Ozob 601:talk 576:talk 550:talk 523:talk 508:talk 504:Ozob 485:talk 456:talk 441:talk 417:talk 413:Ozob 392:talk 367:talk 338:talk 334:Ozob 323:talk 307:talk 291:talk 287:Ozob 266:talk 237:talk 233:Ozob 206:talk 179:talk 153:talk 135:talk 67:edit 44:edit 826:or 804:or 147:by 116:FAC 848:: 789:) 745:r' 714:is 642:) 628:) 603:) 578:) 552:) 525:) 510:) 487:) 458:) 443:) 419:) 394:) 369:) 340:) 325:) 309:) 293:) 268:) 239:) 223:, 208:) 181:) 155:) 137:) 84:• 69:| 50:| 46:| 812:. 784:· 779:( 751:. 638:( 624:( 599:( 574:( 548:( 521:( 506:( 483:( 454:( 439:( 415:( 390:( 365:( 336:( 321:( 305:( 289:( 264:( 235:( 204:( 177:( 151:( 133:( 76:· 73:) 65:( 57:· 54:) 42:(

Index

Knowledge:Peer review
Problem of Apollonius
Article
edit
visual edit
history
Article talk
edit
history
Watch
Watch peer review
automated
house
automated peer review page
FAC
Apollonius of Perga
Willow
talk
18:52, 24 June 2008 (UTC)
Jakob.scholbach
talk
17:26, 26 June 2008 (UTC)
Jakob
Willow
talk
16:13, 27 June 2008 (UTC)
Willow
talk
16:13, 27 June 2008 (UTC)
Solutions to the problem of Apollonius using circle inversion

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