来自《耶鲁大学开放课程：基础物理 第13集 第13集》

• 
  
  It's a particular event
  这是一个特殊的事件
• 
  
  in which x has to be c times t
  其中的 x 必须是 c 乘以 t
• 
  
  because that's the equation for a light pulse, according to me.
  因为对我来说 那是一个光脉冲的等式
• 
  
  Light goes at the velocity of c,
  光速为 c
• 
  
  and the event has got the same velocity, according to you.
  而对于你来说 这个事件有同样的速度
• 
  
  This event here should be connected by a light pulse
  这里这个事件通过光脉冲联系了起来
• 
  
  that for x/t is c,
  即 x/t 等于 c
• 
  
  and x'/t' is the same c.
  x'/t' 同样等于 c
• 
  
  Then, I said, take these three equations,
  然后我要把这三个等式
• 
  
  multiply the left-hand side by the right-hand side,
  左边的式子乘以左边 右边的乘以右边
• 
  
  put in these numbers and extract γ,
  代入这些数字 提出 γ
• 
  
  and I will not repeat that part, and γ was this.
  我不重复这部分推导了 γ 等于这个