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
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The study shows how scientists can essentially turn fiber optic cables into seismometers that return detailed data about earthquakes at the speed of light.
—
Evan Bush, NBC news, 25 Sep. 2025
At any moment in the Universe’s history, there’s a limit to how far a signal that’s been traveling at the speed of light since the start of the hot Big Bang could’ve traveled, and that scale sets what’s known as the cosmic horizon.
—Ethan Siegel, Big Think, 24 Sep. 2025
Additionally, this quasar is also producing jets of particles moving at nearly the speed of light, a rare feature among quasars.
—Rupendra Brahambhatt, Interesting Engineering, 21 Sep. 2025
Meanwhile, lasers travel at the speed of light, can engage with multiple targets, and are famous for their dollar-a-shot ammunition costs.
—New Atlas, 18 Sep. 2025
See All Example Sentences for speed of light
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Evan Bush, NBC news, 25 Sep. 2025
At any moment in the Universe’s history, there’s a limit to how far a signal that’s been traveling at the speed of light since the start of the hot Big Bang could’ve traveled, and that scale sets what’s known as the cosmic horizon.
—Ethan Siegel, Big Think, 24 Sep. 2025
Additionally, this quasar is also producing jets of particles moving at nearly the speed of light, a rare feature among quasars.
—Rupendra Brahambhatt, Interesting Engineering, 21 Sep. 2025
Meanwhile, lasers travel at the speed of light, can engage with multiple targets, and are famous for their dollar-a-shot ammunition costs.
—New Atlas, 18 Sep. 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 5 Oct. 2025.
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