来自《耶鲁大学开放课程：基础物理 第14集 第14集》

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  and you will find the helium's mass
  然后你会发现氦的质量
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  is less than the mass of the two parts.
  小于聚变前两个氢原子质量之和
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  So, there is some energy missing.
  有些能量消失了
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  Some mass missing; that means there's some energy is missing.
  质量消失了就意味着能量消失
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  That's the energy released in fusion.
  少的正是在聚变反应中释放的能量
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  Or you can take uranium nucleus and give it a tap
  或者你也可以通过打击铀核
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  and break it up into barium
  使它裂变为钡
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  and krypton and some neutrons.
  氪和一些中子
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  And you will find the fragments together
  你会发现这三者的质量之和
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  have a mass less than the paired.
  会比分裂之前的小
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  And the missing mass times c2
  消失的质量乘以 c^2
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  is the energy of the reaction
  就是裂变反应释放的能量