So what makes an observable 'material' entity different from empty space?
The answer to this question was given in the theory of mechanical waves pronounced in 1923 by the Nobel Prize winner Prince de Broglie. According to this theory material particles are always linked with a 'system' of travelling waves, a 'wave-packet' or standing wave, forming the constituent parts of matter and determining its movements. A priory assumption is that space is filled with travelling waves. In general these waves neutralize one another, but at certain points it happens that a great number of waves are in such a position, or structure as to reinforce one another and form a marked observable wave crest. This wave crest then corresponds to a material particle! So, the answer to our original question, is that a material entity is a structure made up of standing waves, whose origin are the travelling waves that make up the empty space.
The animation shown here is of a water surface in a closed vibrating tray, made to vibrate to different modes by simply varying the frequency. One can easiely see how a 'system of travelling waves' or better, standing waves, generate what most would call a particle, whilst in fact its just a 3D formation of standing waves. Since, however, the waves may travel in different directions they will part from one another, and the wave crest disappears to re-appear again at a nearby point. The material particle has moved, or better teleported. The same mechanism applies to electromagnetic standing waves which constitute all matter. The wave crest will thus travel in quantum steps, but the velocity with which this is done is quite different from the one with which the underlying wave systems move, that is light speed. The material particle in general moves at right angles to the surfaces of these mechanical waves, just as a ray of light is, as a rule, directed at right angles to the surface planes of the light waves. First we have to accept the fact that every existing location in space is made up of descrete electromagnetic elementary entities. Since this element is filling up a three dimensional space (volume), it has to have its own dimensions in space, with a shape or structure which leaves no discontinuities (or space time void) when neighbouring cells are surrounding it to form a bigger cell. Space time is the product of the volume taken by such element and the time for the element to go through one oscillation. To comprehend this, we must slightly change the concept of what is mass, what is a particle, thus reducing matter and vacuum to the same definition- waves. The actual structural shape is not important at this point, however it should be one which promotes cascading of similar shapes to form bigger macro oscillating structures.
Moving an object of different net electrical properties than its surroundings, means that an external force has to be applied in some way to this object in order to reconfigure the parameters of all the electromagnetic elements in front of that object to the same properties of the moving object, and at the same instant reconfigure all the elements behind the object to that of the surrounding elements. 'In front' and 'behind' being relative to the direction of motion.
From a visual point of view, what we call 'matter' is continously reconstructed in space, whether or not it has a static or dynamic position in space. Simply moving an object by just one millimetre, would mean integrating a huge but discrete number of such a process. That is, motion is not a continous process but rather a huge number of digital processes, crests of standing waves disappearing and reappearing elsewhere in space. Nothing actually moves, motion becomes an interpretation of different shapes at different times. The same applies in the spatial time dimension for stationary objects, since they are 'moving' in the time dimension. In this example, the arrow is composed of the green dielectric, and the surrounding white grid could be vacuum. Each grid size is equal to the size of one planck length, the size of the basic electromagnetic entity, so nothing can exist in between, not even space or time.
The arrow, which could be a mass or particle, is thus seen to be moving, but looking closer, one can see that this is just an optical illusion, the same illusion that makes us believe that an object moves. Reconstruction itself does not need external energy to be applied, because the energy required in front of the moving object is balanced out by that released at the rear. But if we need to change the rate of reconstruction (change in velocity or direction), then external energy would be required to create in imbalance between the front and rear electrical parameters.
This explains the fact that a stationary object needs an external energy source to start motion in space. It also explains inertia. Once a body is moving, it is reluctant to slow down unless external energy is applied (example friction). This is because once the external energy has been used to modify all parameters of EM elements within the object, the object will continue to reconstruct in any location in space with those parameters, until another external energy is applied. This is why a stationary or static object remains still, and a moving object remains moving. It also explains why when a rotating object is no longer restricted in moving round by its centripetal force, it continues to move in a straight line tangent to the point it left on its circular path - it just keeps on the last reconstruction parameters. Note that the above motion properties work linearly only in a uniform time-space volume, that is while the object is travelling through a uniform EM field, similar to the grid shown in the arrow model above.