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Matter that emits little or no detectable radiation of its own, postulated to account for observed gravitational forces that affect astronomical objects but have no observable sources. Dark matter is thought to be part of the missing mass.
(Astronomy) astronomy matter known to make up perhaps 90% of the mass of the universe, but not detectable by its absorption or emission of electromagnetic radiation
a hypothetical form of matter invisible to electromagnetic radiation, postulated to account for gravitational forces observed in the universe.
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|Noun||1.||dark matter - (cosmology) a hypothetical form of matter that is believed to make up 90 percent of the universe; it is invisible (does not absorb or emit light) and does not collide with atomic particles but exerts gravitational force|
matter - that which has mass and occupies space; "physicists study both the nature of matter and the forces which govern it"
cosmogeny, cosmogony, cosmology - the branch of astrophysics that studies the origin and evolution and structure of the universe