Dark Matter -24-------------------------------~-----------R-E-S-O-N-A-N-C
... There have been three reactions to the discovery of dark matter: (i) It doesn't exist; the law of gravitation must be modified so that the stars are all there is to a galaxy. (ii) Dark matter exists, but consists entirely of ord~nary matter - Jupiter-like objects called broum dwarfs that are not mas ...
... There have been three reactions to the discovery of dark matter: (i) It doesn't exist; the law of gravitation must be modified so that the stars are all there is to a galaxy. (ii) Dark matter exists, but consists entirely of ord~nary matter - Jupiter-like objects called broum dwarfs that are not mas ...
Theoretical particle physics Represented by Theory group: Faculty
... time. This is the first evidence of the existence of dark matter. About 40 years later, Vera Rubin et al. studied the galactic rotating curve and found the strong evidence of invisible mass. The finding shows either there is an invisible matter or the Newtonian gravity (or General Relativity) is wro ...
... time. This is the first evidence of the existence of dark matter. About 40 years later, Vera Rubin et al. studied the galactic rotating curve and found the strong evidence of invisible mass. The finding shows either there is an invisible matter or the Newtonian gravity (or General Relativity) is wro ...
Dark Matter— More Than Meets The Eye
... of MACHOs. Because they can warp space enough to focus light from a distant star, MACHOs have played a critical role in a number of microlensing events in the observation of the Large Magellanic Cloud. The diameters of these MACHOs indicated that most of them were either white or brown dwarf stars. ...
... of MACHOs. Because they can warp space enough to focus light from a distant star, MACHOs have played a critical role in a number of microlensing events in the observation of the Large Magellanic Cloud. The diameters of these MACHOs indicated that most of them were either white or brown dwarf stars. ...
Doppler Effect • The Doppler Effect is the change in frequency
... Redshift is an example of the Doppler Effect. It is the term given to the change in frequency of the light emitted by stars, as observed from Earth, due to the stars moving away from us. Redshift has always been present in the light reaching us from stars and galaxies but it was first noticed by ast ...
... Redshift is an example of the Doppler Effect. It is the term given to the change in frequency of the light emitted by stars, as observed from Earth, due to the stars moving away from us. Redshift has always been present in the light reaching us from stars and galaxies but it was first noticed by ast ...
Dark Matter
... bent, causing the distant source to appear at an altered place on the sky and resulting in a tell-tale distortion of its shape. This gravitational lensing effect provides the first, and currently only, way to directly "weigh" cosmic mass. ...
... bent, causing the distant source to appear at an altered place on the sky and resulting in a tell-tale distortion of its shape. This gravitational lensing effect provides the first, and currently only, way to directly "weigh" cosmic mass. ...
Galaxy Clusters
... better understanding of their gravitational interactions. The imagery reveals the assembly history of these close neighbors. ...
... better understanding of their gravitational interactions. The imagery reveals the assembly history of these close neighbors. ...
Last time we left off at hydrogen and helium, because that`s all that
... point no larger collections of matter come together). From the standpoint of life, though, this is still unsatisfactory because dark matter just floats hither and yon, simply orbiting rather than forming complex structures. We therefore have to concentrate on what the ordinary matter is doing at th ...
... point no larger collections of matter come together). From the standpoint of life, though, this is still unsatisfactory because dark matter just floats hither and yon, simply orbiting rather than forming complex structures. We therefore have to concentrate on what the ordinary matter is doing at th ...
Document
... • In the very beginning the expansion was enormous (inflation). The expansion then resumed a lower value • The gravitational formation of large scale structure is dominated by dark matter • Ordinary matter forms the stars, galaxies, and intergalactic gas. It is what we see. • As the universe expands ...
... • In the very beginning the expansion was enormous (inflation). The expansion then resumed a lower value • The gravitational formation of large scale structure is dominated by dark matter • Ordinary matter forms the stars, galaxies, and intergalactic gas. It is what we see. • As the universe expands ...
The Size and Structure of the Milky Way Galaxy
... Dark Matter: A Major Problem for Contemporary Physics and Astronomy • Stars are a small fraction of the mass of major galaxies • The dark matter problem becomes more pronounced as you go out in the universe • The form of the dark matter is unknown; probably not what you studied in chemistry • Possi ...
... Dark Matter: A Major Problem for Contemporary Physics and Astronomy • Stars are a small fraction of the mass of major galaxies • The dark matter problem becomes more pronounced as you go out in the universe • The form of the dark matter is unknown; probably not what you studied in chemistry • Possi ...
Dark matter
Dark matter is a hypothetical kind of matter that cannot be seen with telescopes but would account for most of the matter in the universe. The existence and properties of dark matter are inferred from its gravitational effects on visible matter, on radiation, and on the large-scale structure of the universe. Dark matter has not been detected directly, making it one of the greatest mysteries in modern astrophysics.Dark matter neither emits nor absorbs light or any other electromagnetic radiation at any significant level. According to the Planck mission team, and based on the standard model of cosmology, the total mass–energy of the known 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, while dark energy plus dark matter constitute 95.1% of the total mass–energy content of the universe.Astrophysicists hypothesized the existence of dark matter to account for discrepancies between the mass of large astronomical objects determined from their gravitational effects, and their mass as calculated from the observable matter (stars, gas, and dust) that they can be seen to contain. Their gravitational effects suggest that their masses are much greater than the observable matter survey suggests. Dark matter was postulated by Jan Oort in 1932, albeit based upon insufficient evidence, to account for the orbital velocities of stars in the Milky Way. In 1933, Fritz Zwicky was the first to use the virial theorem to infer the existence of unseen matter, which he referred to as dunkle Materie 'dark matter'. More robust evidence from galaxy rotation curves was discovered by Horace W. Babcock in 1939, but was not attributed to dark matter. The first hypothesis to postulate ""dark matter"" based upon robust evidence was formulated by Vera Rubin and Kent Ford in the 1960s–1970s, using galaxy rotation curves. Subsequently, many other observations have indicated the presence of dark matter in the universe, including 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.Although the existence of dark matter is generally accepted by the mainstream scientific community, some alternative theories of gravity have been proposed, such as MOND and TeVeS, which try to account for the anomalous observations without requiring additional matter. However, these theories cannot account for the properties of galaxy clusters.