An answer to this conundrum is considered as utmost importance to both physics and astronomy. Proper explanation of these anomalies remains without a satisfactory answer after more than five decades. The reader should understand that the quandaries of both Zwicky and Rubin depend on the belief that the quantity and distribution of “normal” matter can be correctly estimated from the galactic luminosity. Investigators also pointed out that presumed DM explains the rotational velocities of stars in low luminosity galaxies better than for luminous galaxies. It still seems uncertain if this grand observation by Rubin also holds for globular and other types of galaxies because observation of individual star motions is more difficult for these galaxy types. This is strongly supported by another group in a study of over 1000 galaxies. Follow-up observations by Rubin and coworkers of the stellar velocities within many other spiral galaxies confirm this observation as a generality. Distant stars circulate at a more frantic pace than those closer to the center contradicting the planetary laws of Kepler objects more distant from the center should be traveling slower than those closer. Instead, the more distant stars travel at much greater velocities relative to those of the interior. For what seems a general rule, the rotational motions of stars about the center of the galactic plane, of spiral-type galaxies, do not follow Kepler’s laws of planetary motion. Stellar motions in spiral galaxies The existence of significant DM was later required to explain another interesting problem of astronomy-the intragalactic motions of stars within the Andromeda galaxy. Zwicky proposed that these three galaxies behaved as if under the influence of a type of plentiful, non-radiating matter, hence DM. These three galaxies were behaving as if each contained much more matter than calculated from the luminosities. He, like all astronomers, estimated matter density assuming that the average density is proportional to the observed luminosity. Fritz Zwicky noted that the motions of these galaxies about a central point could not be properly described using his presumed values for the galaxy matter densities. The first hint for the existence of dark matter (DM) between galaxies was the observation over eight decades ago from a study of the luminosities and centrifugal velocities of three galaxies, a galactic “triplet” of the Coma Cluster. Using our assumption about the importance of the graviton, we here describe the well-known Tully-Fisher relationship of spiral galaxies without resorting to hypothesizing exotic WIMPs or invoking modifications of Newtonian dynamics (MoND). Since the motions of stars and galaxies are non-relativistic, we can apply our idea to describe the expected large-scale motions using only Newtonian mechanics. Particles such as gravitons will be extremely difficult to directly detect the best we can envision is measuring this influence on stellar and galactic motions. Here we consider the possibility that massless gravitons suffering slow redshift may be responsible for the properties of spiral galaxies attributed to dark matter. Likewise, considerations of large, non-emitting objects as the source of most dark matter fall short of expectations. So redshift is actually very easy for astronomers to determine.Several recent attempts to observe dark matter with characteristics similar to atomic or subatomic particles as Weakly Interacting Massive Particles (WIMPs) have failed to detect anything real over a wide energy range.

Gravitational redshift equation