At the speed of light


What is the meaning of the phrase “at the speed of light”?

Very fast/quickly or seemingly instantly (or 299,792,458 meters per second).

What is the origin of the phrase “at the speed of light”?

Interestingly, the Danish astronomer Ole Rømer was credited with the first successful measurement of the speed of light as far back as 1676. He achieved this by observing the eclipses of one of Jupiter’s moons. Rømer’s work was later confirmed and refined by James Bradley in 1729, who used the apparent shift in a star’s position due to Earth’s motion to determine the speed of light. Then, in 1860, James Clerk Maxwell’s equations (1860s) showed that light travels at a constant speed in a vacuum, embedding the idea of a fixed “speed of light” in scientific literature.

According to the laws of physics, the speed of light is the maximum speed at which information or matter can travel according to the laws of physics, specifically the speed of light in a vacuum. This speed is approximately 299,792,458 meters per second.

So the phrase “at the speed of light” has been used in a literal sense for many centuries, however, the phrase only began being used in its figurative sense following Albert Einstein’s special theory of relativity, which was published in 1905. His work was built on the understanding of light and its constant speed, thus establishing the speed of light as a fundamental constant in the universe.

That said, even in its figurative sense, the phrase is predominantly used to refer to something happening extremely quickly or rapidly, rather than the constant pace it would be possible to use it to refer to.

How do you use the phrase “at the speed of light”?

You can use the phrase “at the speed of light” whenever you want to describe something occurring very rapidly, or even instantly. Here are some examples of the phrase in use:

  • “She learned her second language at the speed of light.”: This suggests extremely rapid learning ability.
  • “The information traveled at the speed of light across the globe.”: This highlights the rapid dissemination of information globally.
  • “Rumors spread at the speed of light in social media.”: This highlights the rapid dissemination of information online.
  • “The plane moved at the speed of light.”: This is an exaggeration used to convey the plane’s swift speed.

What are some alternative ways of saying “at the speed of light”?

There are many words and phrases that can often be used synonymously with the phrase “at the speed of light” when it’s used in its figurative sense. Here are some examples:

  • Before you knew it
  • In the blink of an eye
  • Like a bolt from the blue
  • Like greased lightning
  • With lightning speed
  • In a flash
  • In a heartbeat
  • Like a shot
  • At warp speed
  • Hotfoot
  • Without delay
  • In an instant
  • On the double
  • At full tilt

Notable uses of the phrase “at the speed of light”

Literature

Arthur C. Clarke, in his book 2001: A Space Odyssey, published in 1968, wrote “At the speed of light, all past and future are compressed into the now.” Here, he is saying that at the speed of light, the boundaries between past and future dissolve, collapsing all of time into an eternal present.

In Isaac Asimov’s novel Foundation’s Edge, published in1982, spaceships travel at or beyond the speed of light, which is theoretically impossible by Einstein’s physics, thus demonstrating how science fiction uses the phrase to stretch the boundaries of imagination. 

TV and Film

The phrase is deeply embedded into science fiction productions. In Star Trek for example there’s the phrase “Engage warp speed. Let’s get there at the speed of light.” While warp drive technically exceeds the speed of light, the metaphor holds.

Music

The heavy metal band Iron Maiden wrote a song called Speed of Light, released in 2015, where the phrase is used as a metaphor for technological acceleration and existential risk.

In her song Light Years, released in 2000, Kylie Minogue sang “We’re floating around, at the speed of light.” Here, the phrase is romanticized, expressing a dreamlike journey through love and sensation.

Advertising

The phrase “at the speed of light” is often employed in marketing and media to convey notions of efficiency, modernity, and cutting-edge innovation. While not always official slogans, such expressions resonate with the public’s intuitive understanding of speed and technological advancement.

Trend of at the speed of light in printed material over time

Cari Mayhew - Author at Phrase Finder

Cari Mayhew

Lifelong learner, phrase fanatic, and lover of literature across multiple genres. Cari Mayhew has a passion for expression, and a keen curiosity for how phrases begin and how their use transforms over time. She is often found looking for the ideal idiom to convey her thoughts and musings.
At the speed of light

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