A temporal differential explanation of dark matter.
Spiral galaxies form such that there is a gravitational gradient. This gradient is the weakest at the furthest edge and strongest at the center. The gradient is the result of the collective gravitational pull of all objects in the galaxy.
Supposition 2: An observer who witnesses an object within a stronger gravitational field witnesses the object traveling at a slower rate than am observer within the same field as described in the theory of relativity.
Supporting example 1: An object caught in the gravitational pull of a black hole will never cross the event horizon to a distant observer as the time differential eventually causes the object to appear motionless.
Supposition 3: If the natural concentration of matter within a spiral galaxy forms a predictable gradient then there is also a corresponding temporal differential gradient that increases as one moves towards the center of the galaxy. This means stars towards the center will always appear to move more slowly than their actual velocity due to Newtonian physics.
Supposition 4: If the gradient in an appropriate configuration, this would explain why all stars in a galaxy appear to rotate at the same rate. This would occur because stars towards the center would be travelling more slowly due to the temporal differential than stars towards the edge which would appear to be traveling "too fast".
Supposition 5: This illusion would create the logical conclusion that there was a ring of "dark matter" that encircles the galaxy driving the stars on the edge that are travelling "too fast". In actuality any measurement of dark matter would reveal an accurate estimate of the galaxies overall mass.
A temporal differential explanation of dark matter acceleration in the universe.
Supposition 1: Gravitational field lines extended infinitely, even if there overall effect is negligible at most distances.
Supposition 2: Gravitational field lines do exert measurable effects on light at intergalactic scales.
Supposition 3: According to the theory of relativity an object traveling at high velocities emits light that red shifts as it accelerates away from an observer.
Supposition 4: Going back to the common explanation for space-time, which views it as a fabric capable of being stretched, gravitational field lines, even from very distant galaxies, must exert the same stresses on the space in between galaxies. Light must travel across these areas and the gravitational effects must cause a temporal differential.
Supposition 5: As galaxies continue to move away from each other the collective effect of gravity on the space in between galaxies must also weaken over time. As a result light traveling in between galaxies must experience a decreasing temporal differential in the points between galaxies where this collective gravity is weakest. The result is that light in these regions will travel faster through these regions and as gravity in this region continues to weaken, images contained in light passing through these regions would always appear to accelerate, even if the objects were always traveling at the same velocity.
Temporal differentials would explain the effects of dark matter without invoking explainations that require exotic forms of matter that don't exert forces on light that travels through its gravitational field. This explanation would also explain the orderly nature of the orbits of spiral galaxies and the dark matter acceleration of the universe. In fact, if our universe lacked these properties it would create problems within galaxies that would preclude the possibility of life. A galaxy that spun in accordance to Newtonian physics alone would be chaotic, the difference in rotational rates would result in frequent interstellar collisions and constant gravitational disruptions to the formation of solar systems and life itself. This order can be explained in terms of existing physical laws and forms an essential part of the orderly universe in which we live.