你这么看就明白了

送交者: 008 于 2009-01-06, 19:44:34:

回答: MD=molecular dynamics 由 james_hussein_bond 于 2009-01-06, 19:31:04:

你把不可预测, 不可计算, 等等和不可逆混起来了. 假设你算了一个molecular dynamics的过程, 我把它拍成电影. 现在我把这个电影倒着放. 有两种情况:
1. 这个过程完全可逆, 倒着放一点问题都没有
2. 倒着放看上去很怪, 不合"情理", 这说明这个过程是不可逆的. 由于这是分子级别的东西, 唯一可能是违背了热力学的熵增原理.实际上我们现实生活中看见的不可逆过程都是热力学意义的.

这个实验已经被重复过很多次了, 比如武打片里的武林高手飞上墙的时候, 衣服飘的方向就不对头.

所有跟贴:

So you really haven't done a MD simulation. - james_hussein_bond (829 bytes) 2009-01-06, 19:54:48 (291042)
- What do you mean by "then reverse the simulation"? - wasguru (864 bytes) 2009-01-06, 21:20:47 (291082)
  - 行家一出手，便知有没有 (无内容) - ziren (0 bytes) 2009-01-06, 21:39:02 (291095)
  - See this article - james_hussein_bond (626 bytes) 2009-01-06, 21:38:48 (291094)
    - 看到这句话了吗？ - wasguru (150 bytes) 2009-01-06, 21:47:31 (291096)
      - Unfortunately, the page talking about bit-MD is not visible - wasguru (244 bytes) 2009-01-08, 12:02:54 (291714)
      - Here is a book on google that has preview pages - james_hussein_bond (582 bytes) 2009-01-08, 06:58:11 (291677)
      - I don't have access to full text (无内容) - wasguru (0 bytes) 2009-01-07, 21:34:36 (291592)
      - If you simply used lattice MD, then that's true. - james_hussein_bond (226 bytes) 2009-01-07, 21:05:13 (291574)
      - Confining particles on lattice grids simply means rounding coordinates off. - wasguru (86 bytes) 2009-01-07, 20:36:24 (291560)
      - In the old days there used to be a method called lattice MD - james_hussein_bond (132 bytes) 2009-01-07, 20:29:28 (291558)
      - Discretization of what? time, or coordinates? - wasguru (72 bytes) 2009-01-07, 16:25:33 (291500)
      - According to them - james_hussein_bond (254 bytes) 2009-01-07, 16:10:21 (291489)
      - All right. Yes, for LJ(6,12), you don't have to. - wasguru (741 bytes) 2009-01-07, 15:42:40 (291471)
      - You never have to calculate square root if you use Leonard-Jones potential (无内容) - james_hussein_bond (0 bytes) 2009-01-07, 15:24:20 (291451)
      - The problem is, bit-reversible does not mean the simulation is exact - wasguru (639 bytes) 2009-01-07, 14:50:17 (291417)
      - Maybe not for you but evidently a lot of people (wink 008) - james_hussein_bond (130 bytes) 2009-01-07, 14:37:02 (291401)
      - 这样的point，还用的着他去费力气验证？ - wasguru (64 bytes) 2009-01-07, 12:54:46 (291308)
      - That's the point (无内容) - james_hussein_bond (0 bytes) 2009-01-07, 05:40:17 (291168)
  - 你潜水的时间也太长久了. (无内容) - 鹏归 (0 bytes) 2009-01-06, 21:31:53 (291090)
- MD simulation是什么东西我都不知道 (无内容) - 008 (0 bytes) 2009-01-06, 21:11:56 (291076)

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