dark energy

American  

[dahrk en-er-jee] / ˈdɑrk ˈɛn ər dʒi /

noun

1. a hypothetical form of energy whose negative pressure counteracts gravity and is assumed to be responsible for the universe expanding at an accelerating rate.

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dark energy Scientific  

1. A form of energy hypothesized to reside in the structure of space itself, responsible for the accelerating expansion of the universe. Dark energy theoretically counterbalances the kinetic energy of the universe's expansion, entailing that that the universe has no inherent curvature, as astronomical observations currently suggest. Dark energy appears to account for 73 percent of all the energy and matter in the universe.

2. See also big bang

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dark energy Cultural  

1. An as yet unknown and unidentified form of energy that pervades the universe and produces a force that counteracts the gravitational attraction between galaxies.

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Discover More

Dark energy is thought to be responsible for the accelerating universe.

Etymology

Origin of dark energy

First recorded in 1995–2000

Example Sentences

“Living in the deepest corners of our vast cosmos or our mathematical constructs,” the authors write, are still-unsolved scientific mysteries, including dark matter and dark energy.

From The Wall Street Journal • May 19, 2026

At present, dark energy is the best explanation for this behavior, even though its true nature remains unknown.

From Science Daily • Apr. 24, 2026

Such a discovery has the potential to reshape our understanding of gravity, dark energy, and the fundamental workings of the Universe.

From Science Daily • Apr. 24, 2026

Dark matter is believed to be the glue that holds galaxies together, while dark energy pulls them apart by making the universe expand faster and faster over time.

From Barron's • Apr. 22, 2026

According to the Big Bang theory, the universe came into being in one single moment—a cosmic cataclysm that gave birth to black holes, brown dwarfs, matter and dark matter, energy and dark energy.

From "Everything, Everything" by Nicola Yoon