speed of light
noun phrase
: 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
Examples of speed of light in a Sentence
Recent Examples on the Web
The radio signals will hurtle away at the speed of light, or a mind-blowing 670 million mph.
—
Marcia Dunn, Los Angeles Times, 27 May 2025
Think about it – all of this has happened at roughly the speed of light.
—John Werner, Forbes.com, 4 June 2025
In 1959, two physicists predicted another feature of relativistic motion: an object moving near the speed of light should also appear to be rotated.
—ArsTechnica, 31 May 2025
Transmitting at the speed of light The radio antenna in Spain where the piece is being broadcast is about 115 feet across, and is operated by the ESA.
—Rebecca Hersher, NPR, 26 May 2025
See All Example Sentences for speed of light
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Marcia Dunn, Los Angeles Times, 27 May 2025
Think about it – all of this has happened at roughly the speed of light.
—John Werner, Forbes.com, 4 June 2025
In 1959, two physicists predicted another feature of relativistic motion: an object moving near the speed of light should also appear to be rotated.
—ArsTechnica, 31 May 2025
Transmitting at the speed of light The radio antenna in Spain where the piece is being broadcast is about 115 feet across, and is operated by the ESA.
—Rebecca Hersher, NPR, 26 May 2025
See All Example Sentences for speed of light
Cite this Entry
“Speed of light.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/speed%20of%20light. Accessed 1 Jul. 2025.
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