Dark_Matter

Dark Matter There is perhaps no current problem of greater importance to astrophysics and cosmology than that of "dark matter". The controversy, as the name implies, is centered on the notion that there may exist an enormous amount of matter in the Universe that cannot be detected from the light that it emits. The evidence of dark matter is from the motions of astronomical objects, specifically stellar, galactic, and galaxy cluster/super cluster observations. The basic argument is that if we measure velocities in some region, then there has to be enough mass there for gravity to stop all the objects from flying apart. When such velocity measurements are done on large scales, it turns out that the amount of inferred mass is much more than can be explained by the luminous mass. Hence we infer that there is non-luminous matter in the Universe, i.e. there is dark matter. Dark matter has important consequences for the evolution of the Universe. According to standard cosmological theory, the Universe must conform to one of three possible types: open, flat, or closed. A parameter known as the "mass density" - that is, how much matter per unit volume is contained in the Universe - determines which matter, universe, dark, mass, particles, objects, wimps, through, one, massive, large, exist, detected, cold, candidates, two, stars, pass, neutrinos, known, hence, exotic, detectors, crystals, way, under, types, three, stop, speeds, range, possible, photinos