Gravity in Relation to Dark Matter A Brief Discussion

In recent times there has been discussion about the amount of matter in the universe not being consistent with the previous notions of matter and moreover that there is an abundance of a "dark" energy that is pushing the bodies of the universe apart.

The physical cause of gravity, if there is one, has always been a conundrum to physics. As are other observations such as inertia and the effect of gravity on light. General relativity explained much of the problem away and has in many instances proved both predictive and accurate.

However, a discovery in 1998, based around a Type1A supernovae, has thrown this into disarray. Now we have to come up with an explanation as to how the universe can be expanding at an increasing rate.

Sometimes it is useful to look back over our collective notes and see where we may have gone wrong. Gravity is described as a Force or Law of Attraction between two bodies. As suggested by many authors, it is reasonable to define it in terms of its effects. It acts at a distance without intervening media, it acts on all bodies that have mass and it conforms to an inverse square law, meaning that its effect decreases with the square of the distance between the bodies.

It is without question the very essence that binds us together and holds our feet to the Earth as it spins through space. However, its effect is not just on matter but in terms of General Relativity, gravity, or perhaps the interaction of gravity with mass, bends space and time and this effect is visible in the bending of light around a planetary object.

However, the effect that gravity acts at a distance and without any intervening media, though generally accepted in physics has always been troubling. Even Newton in his letters to Bently, confessed a lack of faith in such an idea stating that it was absurd.

It lead to the later abandoned concept of a universal "aether", through which gravity and light acted. Several famous experiments such as the Michelson-Morley experiment and many subsequent experiments, disproved the existence of such an "aether" unless for some reason the aether was always stationary relative to Earth.

For the purpose of this discussion, I again would like to go back to some principles used by the great minds of previous centuries.

For any theory to be valid it must:
1) be simple in conception
2) be in agreement with experience, observation and experiment and,
3) satisfactorily account for and explain all phenomenon sought to be explained.

I believe the latter two are self-explanatory but the idea of simplicity of conception is not always adhered to in physics especially as you delve deeper into ideas like string theory or quantum mechanics. An example of this concept of simplicity as given by others is that it is simpler to believe that the earth rotates on its axis every 24 hours to give us night and day than to believe that the sun orbits around the Earth at tremendous speeds.

That is not to say that sometimes matters are not complex and the correct explanation is not the simple one but even then a larger concept can usually be broken down into simpler ones. Creating an embryo is complex but the individual steps of cell division and differentiation are understandable.

The second point is the one of interest here. New observations by the Hubble telescope create opportunity for new theories if the existing ones do not fit all the observable facts.

If, for discussion, we abandon the idea of gravity as an "attraction" between two bodies it might allow for other ideas to be explored. If we consider the idea of a force acting without communication at a distance may not be the explanation of gravity, then what could it be?

Let us assume for discussions sake that dark energy/dark matter is made of a finite number of particles evenly dispersed throughout the universe. For argument let us assume that these particles are at least subatomic and possess the following properties:

1) That these particles possess both mass and charge. The mass maybe minute and the charge not necessarily a magnitude that we see in existing atomic or subatomic particles,

2) That these particles can move frictionlessly through the universe including the space between atoms and subatomic particles and are continuously in motion,

3) That the speed at which they can move is, or is limited to, the speed of light,

4) That these particles exert a repulsive force on each other acting elastically and keeping themselves evenly dispersed in general but able to be compressed closer to each other transiently,

5) That they can interact with normal (baryonic) matter, (matter as we know it), at some subatomic level, this interaction being in the form of elastic collision or electrostatic repulsion and lastly,

6) That normal (baryonic) matter cannot push on itself but can reflect or interfere with these particles. The degree to which it can interfere with these particles is in direct proportion to what we would call the mass.

These may seem to be a great many assumptions but they do permit the development of a physical explanation for gravity that does not require an unknown attractive effect at a distance without medium of communication.

That dark matter has mass is in keeping with the astronomic observations. The concept of charge is reasonable to postulate as a mechanism for mutual repulsion but is not necessarily something that can be measured easily. It is conceivable that the charge could be the baseline of the universe and all charges we measure are relative to that baseline level. Designing an experiment that could measure such a charge is difficult to imagine but for the moment let us assume that the dark matter carries a charge.

The concept that the particles would move frictionlessly is reasonable and that they are moving continuously and at very high speed (for example, the speed of light) is necessary to explain some of the perceived effects. It may be argued that this would fly in the face or relativity as no particle containing mass could approach the speed of light. So for discussion and without invoking concepts of negative mass lets say that the particles move at speeds relatively close to the speed of light.

Based on the ideas of charge repulsion or elastic collisions, the particles would be forced to disperse as evenly as possible throughout the universe but in the dynamic environment they may be moving and colliding elastically with each other and expanding outward though out the universe.

The interaction with matter could be by elastic collision or conceivably through some electrostatic action. However, the important component of this discussion is that the effect is not transmitted or at least not instantly, through the baryonic matter to the dark matter/energy particles on the opposing side.

So with these assumptions in mind it is possible to postulate that the observed attraction of gravity may be due to repulsion of the surrounding particles and the interaction with matter.

If the dark energy particles are evenly dispersed and acting on each other, then a highly energetic but stable field would be created. At the edges of such a field the dark matter may continue to expand outward. The particles are bouncing back and forth elastically interacting with each other.

If a mass is placed in the center of this field it would be acted on from all sides evenly there would be no net effect. The interaction of the particles extending evenly all the way out to the edge of the universe and back again.

If the mass was placed eccentrically, then it would be moved outward from the center by the unbalanced number of particles on each side, more toward the center and the edge of the universe in that direction than there are on the other side of the mass toward the edge of the universe away from the center.

The number of particles between the mass and the center side (the side it is moving away from) would continue to grow. The particles move and rearrange continuously at the speed of light and as the mass moved from the center of the universe, the imbalance of forces would become greater and the mass would accelerate faster as it moved outward. This imbalance being due to the number of particles bouncing back on forth and interacting with the mass on one side as compared to the number of particles doing the same on the other.

Such an imbalance could explain the observed increasing expansion of the universe.

Now consider the idea of a second body put into the field at some separation from the first then some of the influence of the dark energy particles will be lessened. Imagine the two masses were now side by side. The dark energy particles continuously pressing all around but no such particles between the objects would mean they would be forced together. It would look to an observer, unable to see the dark matter particles as if the objects were attracted to each other. As they are pulled apart, requiring some work to be performed, then particles would begin to intercede between them and the force of "attraction" would appear less.

A similar effect can be seen with two boats on a continuously moving ocean. The waves are reflected away from the boat, more on the outside than between the boats, forcing them together.

This effect is greater the closer the boats become. The same is true with these objects placed in the field of rapidly vibrating particles. The increasing number of these "frantically vibrating and colliding particles" between the bodies, balancing off the effect of similar "frantically vibrating and colliding particles" outside the two bodies, would mean the effect of the apparent attraction would drop away very rapidly with distance and eventually become minute.

Another way to think about it is to imagine the particles are tiny bright lights even dispersed and the bodies of mass are like black spheres blocking light emanating from every particle. The light from the particles on the far side of the second body would be blocked so that the first body would be in a shadow. Conversely the particles on the side of the first body distant from the second body would also be blocked and the second body in a similar shadow. If the light created a "pressure" or push when it hit the spheres, the net effect would be that the spheres would be pushed together.

The effect on each of the masses would be unbalanced; the side facing the other mass having less force acting on it than the side facing away. This effect would become greater as the masses approached each other. Eventually the masses would be brought together and held together by the forces acting outside. It would appear to an observer who could not see any of the dark matter particles that the masses were attracted to each other and this effect became less the further apart the masses moved.

This effect would be negligible at a distance just like gravity but would be increasingly powerful as the bodies moved closer just like gravity. If the "blocking or shadowing" effect is proportional to the mass then the effect would be greater with heavier masses, just as with gravity.

In fact the effect would be directly related to mass but dissipate (due to the geometry) with the inverse square law as seen with gravity. What defines mass is discussed in a separate article.

How electromagnetic radiation could be propagated within this particle field by the movement of these particles, if they possessed a static charge, is discussed in a separate paper. For purposes of illustration of another property, let us assume for the moment that light in the form of a changing electromagnetic field could be propagated by the vibration of the particles described.

Then in a manner somewhat akin to the early descriptions of the ether but not requiring its existence, light is propagated along the field of particles. How then could gravity's effect on light be accounted for?

The observation simply enough is that mass distorts time and space and this can be seen by observing light from a distant star curving around a planetary body on its way to Earth; so called "gravitational lensing".

It would be reasonable to assume that if light were propagated by the particles vibrating in sequence then compression of the particle field may cause the light path to bend in exactly the same way refraction occurs in a lens.

If a mass were placed into the evenly dispersed field then it might displace the particles that would otherwise have to exist in the same time and space. As already suggested the particles will readjust at the speed of light but the ongoing presence of the mass would cause an area of increased density radiating out and decreasing as it went. The amount of increase in density would be in proportion to the mass itself and inversely proportional to the square of the distance from the mass.

If this increase in density could effect the propagation of the EM radiation, as changes in destiny would do to light passing through a transparent medium, then an observer would see the same effect as gravitational lensing.

Discussed elsewhere is the quantum nature of this effect and how diffraction would occur.

Now if these particles were to move freely then a body moving at constant speed would be surrounded by particles in just the same way as a body at rest until the speed of the body started to approach the speed of light at which point the particles could no longer traverse around the object in time to keep the proportions of dark energy particles uniformly distributed around the mass.

A bit like a group of cars moving together on a freeway, their spacing would remain constant while the speed was constant and if one took a snap shot it would not be possible to tell without some outside reference that the cars were moving or still.

Now when a body accelerates there is a period, proportional to the rate of acceleration and the mass, where the particles in the direction of travel are transiently compressed and the particles on the tailing side are transiently decompressed relative to the leading side. The particles rapidly redistribute themselves around the mass at the speed of light but for the period of acceleration the mass experiences a force pushing back against the acceleration which we would consider to be inertia.

The basic Newtonian laws of motion can be explained this way and until the speed approaches a significant proportion of the speed of light it would be accurate. Once relativistic speeds are approached it could be surmised that the particles no longer can move around the mass in relatively short time frame compared to the speed of the mass itself. So the traditional relationships between force, mass and acceleration would no longer apply.

So based on the tenants described above a relatively simple explanation could describe the relationship between mass and the dark particle/energy in the universe and this in turn could explain the observed effects we call gravity and inertia. It can explain all of the observations related to these effects described herein.

Subsequent papers will discuss the relationship between dark energy and light (EM radiation) and the combination of particle and wave like properties seen. The interaction of light with matter in the form of light pressure and the properties of refraction and diffraction are discussed.