- #1
Orion1
- 973
- 3
No, not really, however my question is why has not dark matter been discovered, observed directly in the cosmic background radiation?
Reference:
http://en.wikipedia.org/wiki/Dark_matter
Orion1 said:
No, not really, however my question is why has not dark matter been discovered, observed directly in the cosmic background radiation?
wiki said:In particular, measurements of the cosmic microwave background anisotropies correspond to a cosmology where much of the matter interacts with photons more weakly than the known forces that couple light interactions to baryonic matter.
What is the interaction cross-section between a photon and a non-relativistic neutrino?wiki said:Anisotropy (pronun. with the stress on the third syllable, is the property of being directionally dependent, as opposed to isotropy, which means homogeneity in all directions. It can be defined as a difference in a physical property (absorbance, refractive index, density, etc.) for some material when measured along different axes. An example is the light coming through a polarizing lens.
Orion1 said:Any low-mass free particles that the universe is composed of MUST exist in the CBR as background radiation.
The collision cross-section for dark matter particles is smaller than the electron and magnitudes weaker, of which there is only one candidate in the CBR, the neutrino.
The dark matter in the bullet cluster does not hard scatter, therefore it cannot be composed of heavy mass particles, at least nothing more massive than a neutrino.
Orion1 said:
Even if dark matter were non-baryonic, it would still hard-scatter by collisions as the baryonic matter does in the 'bullet cluster'.
The dark matter in the bullet cluster does not hard-scatter, therefore it cannot be composed of heavy mass particles, at least nothing more massive than a neutrino.
What is the interaction cross-section between a photon and a non-relativistic neutrino?
What is the interaction coupling strength between a photon and a non-relativistic neutrino?
CBR dark matter is a type of matter that emits no light or radiation and therefore cannot be detected through traditional means. It is believed to make up about 85% of the total matter in the universe and plays a crucial role in the formation of galaxies and other large structures.
The discovery of CBR dark matter was made through observations of the cosmic microwave background radiation (CBR), which is the leftover energy from the Big Bang. By studying the fluctuations in the CBR, scientists were able to determine the presence of large amounts of invisible matter that could not be explained by known particles.
The discovery of CBR dark matter has significant implications for our understanding of the universe. It provides evidence for the existence of a type of matter that has long been theorized but never directly observed. It also helps to explain the observed structure of the universe and provides insights into the nature of gravity and the formation of galaxies.
No, CBR dark matter cannot be detected using traditional methods such as telescopes or other instruments that detect light or radiation. However, scientists are working on new technologies and experiments to try and detect CBR dark matter indirectly through its gravitational effects on other matter.
There are several theories about the nature of CBR dark matter, but the most widely accepted one is the Cold Dark Matter (CDM) model. This theory proposes that CBR dark matter is made up of particles that move slowly and clump together due to their gravitational interactions. Other theories include Warm Dark Matter (WDM) and Self-Interacting Dark Matter (SIDM), but more research is needed to determine which theory best explains the properties of CBR dark matter.