Dark matter
Dark matter is an invisible form of matter that does not interact with light or other electromagnetic radiation, but whose existence is revealed by its gravitational effects on visible objects. Dark matter is implied by gravitational effects that cannot be explained by general relativity unless more matter is present than can be observed. According to the standard model of cosmology, dark matter makes up 26.8% of the universe's mass-energy content, constituting 85% of the total mass. Dark matter is thought to serve as gravitational scaffolding for cosmic structures, helping galaxies form and remain bound together. Scientists believe dark matter is likely composed of yet-undiscovered subatomic particles, making it difficult to detect directly in laboratories, though its effects on galaxy rotation and gravitational lensing provide strong evidence for its existence.
Sources
- en.wikipedia.org: “In astronomy and cosmology, dark matter is an invisible and hypothetical form of matter that does not interact with electromagnetic radiation, including light.”
- en.wikipedia.org: “Dark matter is implied by gravitational effects that cannot be explained by general relativity unless more matter is present than can be observed.”
- en.wikipedia.org: “In the standard Lambda-CDM model of cosmology, the mass–energy content of the universe is 5% ordinary matter, 26.8% dark matter, and 68.2% a form of energy known as dark energy. Thus, dark matter constitutes 85% of the total mass”
- en.wikipedia.org: “Dark matter is thought to serve as gravitational scaffolding for cosmic structures.”
- en.wikipedia.org: “The most prevalent explanation is that dark matter is some as-yet-undiscovered subatomic particle, such as either weakly interacting massive particles (WIMPs) or axions.”