Even if ET has mastered building a rocket that can travel at the speed of light, he may be lying dead inside a weakened craft .

即使外星人已经掌握了制造一枚能以光速飞行的火箭的技术，他也可能死在了一架飞船里。

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Signals travel at the speed of light.

信号以光的速度传播。

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Radio waves also travel at the speed of light.

无线电波也是以光速传播的。

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c We know it's very specific for light because in this equation is c, the speed of light. So any time you go to use this equation, if you're trying to use it for an electron, just ask yourself first, does an electron travel at the speed of light?

我们知道它只对光适用是因为在这个方程里有,光速，所以下次你们用这个方程前，如果你们要把它用到一个电子上，先问问你自己，电子的运动速度是光速吗？

麻省理工公开课 - 化学原理课程节选

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