The void is not space. Space is aether, and aether is particles. The void is an infinity of nothing, something we don’t ever experience because all around us we have space, radiation and objects of inertial matter.
However, the void is not merely a philosophical starting point. If we are right in assuming that everything, including space, are particles, we must also accept the void as real, because we need a bit of nothing in between aether particles to keep things going.
If we stick with our assumption that aether particles are spherical, we can imagine them as tiny steel balls, and we know from experience that balls of equal size leave little gaps between them when stacked. There is no way we can stack spheres without leaving a lot of gaps. At the aether level, these gaps are voids. Every one of them is a tiny infinity of nothing.
Furthermore, every aether particle moves at the speed of light. The neat packaging that is possible with stationary balls is not possible with the aether. The gaps between the particles are constantly changing in size, and the particles themselves hardly touch their neighbors as they zip past each other.
But the weirdest thing of all is that our definition of the void is such that there never is any separation between the neighbors, in any direction. The gaps are all infinities of nothing. While these gaps are bigger in some directions than others, they are all nothing. This leads us to David Hilbert’s infinity paradox, in which some infinities are bigger than other infinities.
A consequence of this is that we’ll need to use some really exotic math in order to describe the aether completely. It might be that this is where we find a reason for why all aether particles inside a given reference frame must move at the same speed as all other aether particles. It may give us better ways to describe surface textures of particles. Maybe they span the gaps? I don’t know. However, I do know that things get seriously weird when we go down to this level of detail.