Thats a little like asking why can physical/energy not be created nor destroyed, or why is our finite physical/energy Universe a perpetual motion machine, or........?
,
Matter = associative/convergent properties, factors elements whatever of physical/energy
Universe.
And this may boil-out entropically to a large, least energy/frequency( longest wave ) photon, that has no reason in of itself to recollapse as fermionic matter.
So, we may infer that what keeps the eternally perpetuation of Universe, is the mass-attractive, associatively convergent(
>IN< ) properties of gravity aka
gravitational spacetime eternally existent on the outer perimeter of EMRadiation's existence.
Why and how does convergent
>IN< occur is the question. Well let me take a crack-at-it by first putting aside motion or what is moving let me offer some geometrical thoughts.
http://www.rwgrayprojects.com/synergetics/plates/figs/plate08z.html
But also, putting aside the link above, see later more complex scenario below for those daring enough to ponder geometry more complex than a triangle.
So, I offer the most simplest of concepts that actually involves and enclosure of space, albeit, a 2D space.
What if at minimum, we had zn integrated set of three angles( 3-viewpoints/3-points-of-view ). I see that as an imbalance i.e. 3 is odd number set.
Sort of like two up quarks and one down quark of a baryonic hadron. There exists this imbalance/asymmetry(?) that is eternally chasing its own tail to arrive at balance/equilibrium. Yet this can never happen, because of the nature of the triangle being a self-stablizing unit of three diagonals/stabilizers.
With a short-lived( very unstable ) meson( two quarks ) we have appear to have less stable version of only twoness. But be clear here, I'm only using quarks as and example. The 3 viewpointed triangle as perhaps the minimal gravitational spacetime, is a differrent scenario.
Anyway, to keep these simple version simple, I will leave it there.
Below is a more complex scenario that involves both a set of 24 triangle-based viewpoints and 24 square-based viewpoints integrated as whole integrated set.
http://www.rwgrayprojects.com/synergetics/plates/figs/plate08z.html
What may not be stated in the above link is the relation of 8 closed triangles and 12 radial lines-- total 24 lines-of-relationship ---as found with the Vector Equlibrium( VE ) aka Fullers operating system of Universe.
This VE, in its toy-like transformable mode, l transforms into many exotic shapes and I ask others to only consider one of them as follows;
EM double sine-wave = two electric peaks and valleys--- amplitude--v^--> ---and two magnetic peaks and valleys( amplitude--V^--> )traveling in same overall direction, the that are at 90 planes to to each other if I understand correctly and the VE transform into this geometric configuration.
What most do not realize is, that there is balance of 6 lines-of-relationship in each triangle wave in the Euclidean double sine wave formed by the jitterbug,
however, what is not seen/observed from the beginning is that each square has and additional one or two gravitational lines-of-relationship, that are not part of the 24 patterned set. It would take 6 lines-of-relationship diagonals to stablize the 6 squares of the VE and then we have 30 lines-of-relationship and then the pattern is that of a the more stable icosahedron and in its proper orientation more spherical than the VE/cubo-octahedron.
r6