Kakeya needle problem 答案是arbitrarily small

送交者: lightman 于 2009-01-15, 03:22:23:

Wiki里都说了，引用的都没仔细看吗？

http://en.wikipedia.org/wiki/Kakeya_set#Kakeya_needle_problem

引用：

Besicovitch[2] was able to show that there is no lower bound > 0 for the area of such a region D, in which a needle of unit length can be turned round.

所有跟贴:

这个理论好，就叫资源紧张的条件下创建和谐社会的数学基础 (无内容) - 田野 (0 bytes) 2009-01-15, 08:13:45 (293233)
如果为0的话，问题已经变质了吧？ - 田野 (21 bytes) 2009-01-15, 08:10:20 (293232)
- What makes you think of "如果为0"? - LaoXiao (108 bytes) 2009-01-15, 08:45:51 (293235)
  - “Besicovitch's work - 田野 (109 bytes) 2009-01-15, 11:25:02 (293251)
  - "Adapting this method further, - 田野 (143 bytes) 2009-01-15, 11:15:50 (293248)
    - Thanks for the info. It talks about, however, - LaoXiao (142 bytes) 2009-01-15, 12:16:34 (293270)
      - The limit is also a Besicovitch set - lightman (207 bytes) 2009-01-15, 15:24:24 (293324)
        
        Agree. - LaoXiao (403 bytes) 2009-01-15, 16:20:11 (293339)
挂谷问题(Kakeya needle problem)是如何想出来的? - sl (393 bytes) 2009-01-15, 03:44:42 (293217)
- 挺好，我看到这个题目时就觉得这是个很实用的问题， - 老中乙号 (170 bytes) 2009-01-15, 05:24:00 (293220)
  - "一开始就是由生产决定的", 后来就被数学家搞歪了．什么测度为０也搞出来了． (无内容) - 008 (0 bytes) 2009-01-15, 13:42:24 (293286)

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