Dark Matter is a form of matter which is thought to account for approximately 85% of the matter in the universe and the remaining is made up visible or baryonic matter. Its presence is implied in a variety of astrophysical observations, including the gravitational affects has on the orbits of stars in galaxies which cannot be explained by accepted theories of gravity unless more matter is present than can be seen. The reason it is called dark is because it does not appear to interact with the electromagnetic field, which means it does not absorb, reflect or emit electromagnetic radiation, which is why it is difficult to detect.
However, we disagree that it cannot be explained by accepted theories of gravity because Einstein defined gravity in terms of the “depth” of a gravity well or distortion in the “surface” of space-time caused by the energy density of an environment and NOT on existence of visible or baryonic matter. This means the energy of electromagnetic fields, photons and all other forms of energy along with that associated with visible matter must be taken consideration when determining the energy density of space and therefore its gravitational potential.
This suggests the reason it does not appear to interact with an electromagnetic field is because a large part it MAY BE made up of an electromagnetic field.
The observation electromagnetic energy prevents the visible matter in stars from collapsing to a black hole or falling to the button of its gravity well supports this conclusion because it tells us its gravitational potential MUST BE oppositely directed with respect to that of visible matter.
Some might say, if that were true it should have the same effect on the orbits of planets as it does on stars in galaxies. However, the reason it DOES NOT is because the offset it creates would be affect the gravitational field of the entire solar system. Therefore, objects that are gravitationally bound to a star would only experience the gravitational potential of its visible matter.
One can understand why by using an analogy of a jar containing water and oil where the water represents gravitational potential of electromagnetic energy while the oil represents that of visible matter. The water prevents the oil from sinking to the bottom because its “directional energy” is opposite or is more buoyant than the water. This would be analogous to how electromagnetic energy prevents the visible matter in stars from sinking to the bottom of a stars gravity well.
However, as was mentioned earlier Einstein defined gravity in terms of the “depth” of a gravity well or distortion in the “surface” of space-time caused by the energy density of an environment NOT on existence of visible of baryonic matter.
Therefore, to determine the TOTAL gravitational potential or depth of the gravity well of a solar system one must ADD the energy density associated with electromagnetic energy to that of its visible matter.
Yet, to define the gravitational potential on objects which ARE GRAVITATIONALLY bound to a star one would HAVE TO use only that contributed by the visible matter because, as mentioned earlier a solar systems gravity well is offset by the electromagnetic energy. Therefore, any objects gravitational bound to a star would only be affected by the gravitational potential of the visible matter.
This would be analogous how one inside the jar, mentioned above would measure the height of the oil with respect to the water line.
Similarly, a planet inside a solar system would measure the gravitational potential it would experience from “height” associated with the visible matter with respect to the “height” of the gravitational potential of its electromagnetic energy.
One can also use the example of the jar mentioned earlier to understand why galaxies in galactic clusters and stars orbiting in them are affected by BOTH the gravitational potential of electromagnetic energy and visible matter.
For example, one outside the jar would add the height of the oil to the water to get its total height
Similarly, galaxies in galactic clusters and stars that are not gravitational bound to a solar system would experience the gravitational potential contributed by both the visible matter electromagnetic energy for the same reason that one who was outside the jar mentioned earlier would measure the height above its bottom in by adding the height of the water to the oil.
This means according to Einstein the total gravitation potential of the universe must be at least TWICE that contributed by the visible matter of a healthy star because it is in equilibrium with oppositely directed gravitational energy he associated with its electromagnetic energy.
He also tells us ANY FORM of energy that COUNTERACTS that of the gravitational potential of visible matter must also be consider a component of the Dark Matter. For example, the orbital energy of the stars in a galactic would have to be included because it also adds to the energy density of the space they occupy. In other words, not only do you have to add the energy density contributed by electromagnetic energy to that of the visible matter in stars but you must also add their orbital energy to determine to determine their total gravitational potential of a galaxy. Additionally, the fact that galaxies are gravitational bound in galactic clusters means you must also consider the energy density contributed by their rotational energy to the Dark mater component of the universe.
Additionally, the OBSERVATION that electromagnetic energy offsets the gravitational potential of the visible matter tells us that it must contribute AT LEAST an equal amount to universe total. The remaining Dark matter could be provided by the energy density contributed by dust, helium atoms, black holes along their orbital energy.
It should be remembered; Einstein defined the depth of a gravity well in space in terms of the ABSOLUTE value of its energy density. Therefore, to determine the total gravitational potential of both Dark and visible matter one must include all forms of energy to determine their value.