speed of light
Americannoun
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Physics, Optics. a fundamental universal constant, the speed at which light and all forms of electromagnetic radiation travel in a vacuum, standardized as 186,282.4 miles per second (299,792,458 meters per second).
The speed of light, often represented by the letter c, figures prominently in modern physics, as in Einstein’s famous equation E = mc2, which expresses the relation between mass (m) and energy (E).
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an extremely fast rate.
They gobbled those appetizers up at the speed of light.
Etymology
Origin of speed of light
First recorded in 1820–25
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
"If software and AI models move at the speed of light, energy and hardware move at the speed of physics."
From Barron's
From this disk, intense jets of material were launched at nearly the speed of light.
From Science Daily
Diamond Light Source is a synchrotron, which fires electrons around a giant ring at nearly the speed of light.
From BBC
As the flare diminished, high-velocity winds appeared, racing outward at roughly one-fifth the speed of light.
From Science Daily
Cosmic rays -- high-energy particles moving close to the speed of light -- are known to arrive from within the Milky Way and from more distant regions of the universe.
From Science Daily
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
