At the speed of light
Meaning
To move, happen, or perform with extreme and unimaginable swiftness, often referring to the fastest possible rate.
Origin
The idea of an ultimate speed limit for everything in the universe was a profound revelation of 20th-century physics, primarily championed by Albert Einstein's theories of special and general relativity. While scientists like Ole Rømer had made early attempts to measure the speed of light in the 17th century, it was Einstein's groundbreaking work in the early 1900s that popularized "c" (the speed of light in a vacuum) as a universal constant—the fastest anything can possibly travel. This fundamental constant of nature, representing an incredible 299,792,458 meters per second, quickly entered the popular lexicon as the ultimate metaphor for unimaginable velocity, turning a complex scientific principle into a punchy, everyday phrase describing anything incredibly fast.
Examples
- The new fiber optic internet connection can download large files at the speed of light.
- When the doorbell rang, the dog shot off the couch and ran to the door at the speed of light.