来自《耶鲁大学开放课程：基础物理 第13集 第13集》

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  but you've got to do a little more work.
  但那样计算过程会麻烦些
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  It's a lot easier here,
  还是这么做比较简单
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  because I get to pump into the equation two facts at one shot,
  因为同时把两个信息融合到一个式子里了
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  that the time between the two ticks is 1 second
  两次响声间隔为 1 秒
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  and it's at rest with respect to me,
  还有就是 钟表相对与我是静止的
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  which is why the Δx vanished between the two ticks.
  在两次响声间 Δx 数值为 0
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  If I want to use your equations,
  如果要用你的方程解答
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  Δx' won't be 0
  Δx' 不是 0
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  because the clock has moved,
  因为钟的位置移动了
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  and you've got to do... you can do it.
  你就要做很多计算 也能解出来
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  I have, I think, shown in my notes how to do that but it's unnecessary.
  我的课堂笔记中有解法 但那不重要
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  This is the main result.
  这个结果最重要