Definitions for dark matter
dark mat·ter

Princeton's WordNetRate this definition:0.0 / 0 votes

1. dark matternoun

   (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

WiktionaryRate this definition:0.0 / 0 votes

1. dark matternoun

   Particles of matter that cannot be detected by their radiation but whose presence is inferred from gravitational effects.

WikipediaRate this definition:0.0 / 0 votes

1. Dark matter

   Dark matter is a hypothetical form of matter thought to account for approximately 85% of the matter in the universe. Dark matter is called "dark" because it does not appear to interact with the electromagnetic field, which means it does not absorb, reflect, or emit electromagnetic radiation and is, therefore, difficult to detect. Various astrophysical observations – including gravitational effects which cannot be explained by currently accepted theories of gravity unless more matter is present than can be seen – imply dark matter's presence. For this reason, most experts think that dark matter is abundant in the universe and has had a strong influence on its structure and evolution.The primary evidence for dark matter comes from calculations showing that many galaxies would behave quite differently if they did not contain a large amount of unseen matter. Some galaxies would not have formed at all and others would not move as they currently do. Other lines of evidence include observations in gravitational lensing and the cosmic microwave background, along with astronomical observations of the observable universe's current structure, the formation and evolution of galaxies, mass location during galactic collisions, and the motion of galaxies within galaxy clusters. In the standard Lambda-CDM model of cosmology, the total mass-energy content of the universe contains 5% ordinary matter, 26.8% dark matter, and 68.2% of a form of energy known as dark energy. Thus, dark matter constitutes 85% of the total mass, while dark energy and dark matter constitute 95% of the total mass-energy content.Because no one has directly observed dark matter yet – assuming it exists – it must barely interact with ordinary baryonic matter and radiation except through gravity. Dark matter is thought to be non-baryonic; it may be composed of some as-yet-undiscovered subatomic particles. The primary candidate for dark matter is some new kind of elementary particle that has not yet been discovered, particularly weakly interacting massive particles (WIMPs), Many experiments to detect and study dark matter particles directly are being actively undertaken, but none have yet succeeded. Dark matter is classified as "cold," "warm," or "hot" according to its velocity (more precisely, its free streaming length). Current models favor a cold dark matter scenario, in which structures emerge by the gradual accumulation of particles. Although the scientific community generally accepts dark matter's existence, some astrophysicists, intrigued by specific observations that are not well-explained by ordinary dark matter, argue for various modifications of the standard laws of general relativity. These include modified Newtonian dynamics, tensor–vector–scalar gravity, or entropic gravity. These models attempt to account for all observations without invoking supplemental non-baryonic matter.

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1. dark matter

   Dark matter is a type of matter hypothesized in astrophysics and cosmology that cannot be directly observed because it does not emit or interact with observable electromagnetic radiation, such as light. Still, its existence and properties are deduced from its gravitational effects on visible matter, radiation, and the structure of the universe. It is estimated to constitute approximately 85% of the matter in the universe and about a quarter of its total mass-energy density.

WikidataRate this definition:0.0 / 0 votes

1. Dark matter

   In astronomy and cosmology, dark matter is a type of matter hypothesized to account for a large part of the total mass in the universe. Dark matter cannot be seen directly with telescopes; evidently it neither emits nor absorbs light or other electromagnetic radiation at any significant level. Instead, its existence and properties are inferred from its gravitational effects on visible matter, radiation, and the large-scale structure of the universe. According to the Planck mission team, and based on the standard model of cosmology, the total mass–energy of the universe contains 4.9% ordinary matter, 26.8% dark matter and 68.3% dark energy. Thus, dark matter is estimated to constitute 84.5% of the total matter in the universe and 26.8% of the total content of the universe. Dark matter came to the attention of astrophysicists due to discrepancies between the mass of large astronomical objects determined from their gravitational effects, and the mass calculated from the "luminous matter" they contain: stars, gas and dust. It was first postulated by Jan Oort in 1932 to account for the orbital velocities of stars in the Milky Way, and by Fritz Zwicky in 1933 to account for evidence of "missing mass" in the orbital velocities of galaxies in clusters. Subsequently, many other observations have indicated the presence of dark matter in the universe, including the rotational speeds of galaxies by Vera Rubin, in the 1960s–1970s, gravitational lensing of background objects by galaxy clusters such as the Bullet Cluster, the temperature distribution of hot gas in galaxies and clusters of galaxies, and more recently the pattern of anisotropies in the cosmic microwave background. According to consensus among cosmologists, dark matter is composed primarily of a not yet characterized type of subatomic particle. The search for this particle, by a variety of means, is one of the major efforts in particle physics today.

Matched Categories

1. • Cosmology
   • Matter

How to pronounce dark matter?

1. Alex

   US English

   David

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   Mark

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   Daniel

   British

   Libby

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   Mia

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   Karen

   Australian

   Hayley

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   Priya

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   Neerja

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   Oliver

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How to say dark matter in sign language?

Numerology

1. Chaldean Numerology

   The numerical value of dark matter in Chaldean Numerology is: 2

2. Pythagorean Numerology

   The numerical value of dark matter in Pythagorean Numerology is: 3

Examples of dark matter in a Sentence

1. Wendy Freedman:

   The GMT will herald the beginning of a new era in astronomy. The GMT will reveal the first objects to emit light in the universe, explore the mysteries of dark energy and dark matter, and identify potentially habitable planets in the Earth's galactic neighborhood, the decision by the GMTO partner institutions to start construction is a crucial milestone on our journey to making these amazing discoveries using state-of-the-art science, technology and engineering.

2. Jonathan Davis:

   We know dark matter exists around galaxies and we want to ask — if light from the galaxy can scatter off the dark matter, like a dust cloud, can you actually observe this light?

3. Kotaro Kohno:

   The more massive a galaxy, the more massive the supermassive black hole at its heart. So the study of these galaxies and their evolution will tell us more about the evolution of supermassive black holes, too, massive galaxies are also intimately connected with the distribution of invisible dark matter. This plays a role in shaping the structure and distribution of galaxies. Theoretical researchers will need to update their theories now.

4. Masashi Chiba:

   This discovery implies hundreds of faint dwarf satellites waiting to be discovered in the halo of the Milky Way, how many satellites are indeed there and what properties they have, will give us an important clue of understanding how the Milky Way formed and how dark matter contributed to it.

5. Jonathan Feng:

   If true, it’s revolutionary, for decades, we’ve known of four fundamental forces: gravitation, electromagnetism, and the strong and weak nuclear forces. If confirmed by further experiments, this discovery of a possible fifth force would completely change our understanding of the universe, with consequences for the unification of forces and dark matter.

References

1. ^ Princeton's WordNet
   http://wordnetweb.princeton.edu/perl/webwn?s=dark matter
2. ^ Wiktionary
   https://en.wiktionary.org/wiki/Dark_Matter
3. ^ Wikipedia
   https://en.wikipedia.org/wiki/Dark_Matter
4. ^ ChatGPT
   https://chat.openai.com
5. ^ Wikidata
   https://www.wikidata.org/w/index.php?search=dark matter