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speed of light

Definition of speed of light

  1. :  a fundamental physical constant that is the speed at which electromagnetic radiation propagates in a vacuum and that has a value fixed by international convention of 299,792,458 meters per second —symbol c

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First Known Use of speed of light

1823

Learn More about speed of light

  1. See words that rhyme with speed of light Britannica.com: Encyclopedia article about speed of light

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