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Hausdorff paradox

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bounded subsets in the Euclidean plane (as well as "length" on the real line) in such a way that congruent sets will have equal "area". (This
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plays a crucial role here – the statement is not true on the plane or the line. In fact, as was later shown by
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subsets which is equal on congruent pieces. (Hausdorff first showed in the same paper the easier result that there is no
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defined on all subsets such that the measure of congruent sets is equal (because this would imply that the measure of
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on sets for which the latter exists.) This implies that if two open subsets of the plane (or the real line) are
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This paradox shows that there is no finitely additive measure on a sphere defined on
94: 492:"Sur la dĂ©composition des ensembles de points en parties respectivement congruentes" 487: 21: 558: 524: 29: 420: 494:, Theorem 16, Fundamenta Mathematicae 6: pp. 244–277, 1924. 404:
uses Hausdorff's ideas. The proof of this paradox relies on the
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additive measure defined on all subsets.) The structure of the
490:, Fundamenta Mathematicae 4: pp. 7–33, 1923; Banach, 435:, however, is only finitely additive, so it is not a 363: 335: 307: 279: 248: 216: 182: 160: 132: 103: 67: 37: 400:, the same year. The proof of the much more famous 377: 349: 321: 293: 261: 230: 202: 168: 146: 118: 84: 52: 385:of the non-zero measure of the whole sphere). 8: 509:"Bemerkung ĂĽber den Inhalt von Punktmengen" 427:, it is possible to define an "area" for 367: 362: 339: 334: 311: 306: 280: 278: 253: 247: 217: 215: 183: 181: 161: 159: 133: 131: 109: 104: 102: 75: 71: 70: 68: 66: 43: 38: 36: 60:(the surface of a 3-dimensional ball in 476: 394:in 1914 and also in Hausdorff's book, 439:in the full sense, but it equals the 7: 242:. In particular, it follows that on 85:{\displaystyle {\mathbb {R} ^{3}}} 14: 421:group of rotations on the sphere 93:). It states that if a certain 488:"Sur le problème de la mesure" 1: 537:(Original article; in German) 388:The paradox was published in 447:then they have equal area. 601: 544:GrundzĂĽge der Mengenlehre 541:Hausdorff, Felix (1914). 507:Hausdorff, Felix (1914). 462: â€“ Geometric theorem 397:GrundzĂĽge der Mengenlehre 294:{\displaystyle {B\cup C}} 271:finitely additive measure 231:{\displaystyle {B\cup C}} 466:Paradoxes of set theory 203:{\displaystyle {A,B,C}} 119:{\displaystyle {S^{2}}} 97:subset is removed from 53:{\displaystyle {S^{2}}} 575:Mathematical paradoxes 379: 351: 323: 295: 263: 232: 204: 170: 148: 120: 86: 54: 513:Mathematische Annalen 460:Banach–Tarski paradox 402:Banach–Tarski paradox 391:Mathematische Annalen 380: 352: 324: 296: 264: 262:{\displaystyle S^{2}} 233: 205: 171: 149: 147:{\displaystyle {A,B}} 121: 87: 55: 580:Theorems in analysis 361: 333: 305: 277: 246: 214: 180: 158: 130: 101: 65: 35: 378:{\displaystyle 2/3} 350:{\displaystyle 1/2} 322:{\displaystyle 1/3} 169:{\displaystyle {C}} 525:10.1007/bf01563735 375: 347: 319: 301:is simultaneously 291: 259: 228: 200: 166: 144: 116: 82: 50: 28:. It involves the 559:Hausdorff Paradox 445:equi-decomposable 18:Hausdorff paradox 592: 548: 536: 495: 481: 441:Lebesgue measure 384: 382: 381: 376: 371: 356: 354: 353: 348: 343: 328: 326: 325: 320: 315: 300: 298: 297: 292: 290: 268: 266: 265: 260: 258: 257: 237: 235: 234: 229: 227: 209: 207: 206: 201: 199: 175: 173: 172: 167: 165: 153: 151: 150: 145: 143: 125: 123: 122: 117: 115: 114: 113: 91: 89: 88: 83: 81: 80: 79: 74: 59: 57: 56: 51: 49: 48: 47: 20:is a paradox in 600: 599: 595: 594: 593: 591: 590: 589: 565: 564: 555: 540: 506: 503: 501:Further reading 498: 482: 478: 474: 456: 450: 406:axiom of choice 359: 358: 331: 330: 303: 302: 275: 274: 249: 244: 243: 212: 211: 178: 177: 156: 155: 128: 127: 105: 99: 98: 69: 63: 62: 39: 33: 32: 26:Felix Hausdorff 12: 11: 5: 598: 596: 588: 587: 585:Measure theory 582: 577: 567: 566: 563: 562: 554: 553:External links 551: 550: 549: 538: 519:(3): 428–434. 502: 499: 497: 496: 475: 473: 470: 469: 468: 463: 455: 452: 433:Banach measure 374: 370: 366: 346: 342: 338: 318: 314: 310: 289: 286: 283: 256: 252: 226: 223: 220: 198: 195: 192: 189: 186: 164: 142: 139: 136: 112: 108: 78: 73: 46: 42: 13: 10: 9: 6: 4: 3: 2: 597: 586: 583: 581: 578: 576: 573: 572: 570: 560: 557: 556: 552: 546: 545: 539: 534: 530: 526: 522: 518: 514: 510: 505: 504: 500: 493: 489: 485: 484:Stefan Banach 480: 477: 471: 467: 464: 461: 458: 457: 453: 451: 448: 446: 442: 438: 434: 430: 426: 422: 418: 414: 409: 407: 403: 399: 398: 393: 392: 386: 372: 368: 364: 344: 340: 336: 316: 312: 308: 287: 284: 281: 272: 254: 250: 241: 224: 221: 218: 196: 193: 190: 187: 184: 162: 140: 137: 134: 110: 106: 96: 92: 76: 44: 40: 31: 27: 23: 19: 561:on ProofWiki 547:(in German). 543: 516: 512: 479: 449: 428: 416: 412: 410: 395: 389: 387: 269:there is no 24:named after 17: 15: 22:mathematics 569:Categories 472:References 176:such that 533:123243365 417:countably 285:∪ 240:congruent 222:∪ 95:countable 454:See also 238:are all 437:measure 531:  425:Banach 357:, and 30:sphere 529:S2CID 210:and 154:and 16:The 521:doi 429:all 413:all 408:. 571:: 527:. 517:75 515:. 511:. 486:, 329:, 535:. 523:: 373:3 369:/ 365:2 345:2 341:/ 337:1 317:3 313:/ 309:1 288:C 282:B 255:2 251:S 225:C 219:B 197:C 194:, 191:B 188:, 185:A 163:C 141:B 138:, 135:A 111:2 107:S 77:3 72:R 45:2 41:S

Index

mathematics
Felix Hausdorff
sphere
R 3 {\displaystyle {\mathbb {R} ^{3}}}
countable
congruent
finitely additive measure
Mathematische Annalen
GrundzĂĽge der Mengenlehre
Banach–Tarski paradox
axiom of choice
group of rotations on the sphere
Banach
Banach measure
measure
Lebesgue measure
equi-decomposable
Banach–Tarski paradox
Paradoxes of set theory
Stefan Banach
"Sur le problème de la mesure"
"Sur la décomposition des ensembles de points en parties respectivement congruentes"
"Bemerkung ĂĽber den Inhalt von Punktmengen"
doi
10.1007/bf01563735
S2CID
123243365
GrundzĂĽge der Mengenlehre
Hausdorff Paradox
Categories

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