Dark Matter
| Professors: Cayon, Cui, Lee, Peterson Dark matter, in astronomy, usually means cold, non-baryonic dark matter. This is a form of mass which reacts with other matter via only gravity and possibly the weak force. It also comprises approximately 80% of all matter in the universe. There is also baryonic dark matter, which is just ordinary matter, like dust, gas, rocks, and even stars. And there is also hot, non-baryonic dark matter, which is just neutrinos. Dark matter was postulated in 1934 to account for evidence of "missing mass" in orbital velocities of galaxies in clusters. Since then, other observations have shown presence of dark matter in the universe: rotational speeds of galaxies, gravitational lensing, and temperature distribution of hot gas. Dark matter is a major contributor to the modeling of structure formation and galaxy evolution and has measureable effects on the anisotropies in the cosmic microwave background. All the evidence suggest that the universe as a whole contains more matter that interacts with electromagnetic radiation. Despite indirect evidence, direct evidence of dark matter existance and solid understanding remains elusive. Hence, why on-going research to find and understand it is very exciting. |
 The image of part of the three dimensional distribution of clumps of dark matter in our universe, produced by an extensive survey using the Hubble telescope |