Amazingly, recent galaxy-cluster mapping has shown geometry!
The local voids to outline Close-packed Octahedra!!!
(I lost the link to references on this - if anyone has updates or similar discoveries, please forward them to me. This is fascinating!)

This seems stunning, but is probably due to gravitational / expansive forces finding equilibrium in minimum-energy vectors.
If we have 2 octahedrons (and presumably more in a 3-D grid) then we also have tetrahedral voids, because octahedrons
don't fill-space (like stacking cubes). It requires alternating Octa-Tetra combination to fill space in this type matrix.
More on the surprising geometry of this pattern below ...



Below:
This is the full pattern implied by the supercluster geometry, it's what is called a 'Space Frame' trusswork.
It was discovered and patented by visionary genius Buckminster Fuller and patented in 1961. One amazing feature
is that in examining the matrix you can find all the other platonic solids outlined except those with 5-symmetry.
Look at these different angles of the oct-tet matrix and notice you can see outlines of octahedra, tetrahedra, truncated tetrahedra,
nested tetrahedra, cubes, cubes with tetrahedra inside, rhomboids, and more ...


It was later discovered that Alexander G. Bell has come upon the same structure in 1903,
but Bell was looking to build a practical lightweight platform & didn't notice the deeply fundamental nature of
the spaceframe as the maximum self-reinforcing structure possible in platonic 3-D geometry.

The most amazing thing is this arrangement happens anytime spheres are packed together.
It's the most economical, space/energy conserving arrangement of equal size spheres.
Spheres pack 12 around 1 - each sphere in the matrix is touching 12 other spheres and
connecting grid-lines (force vectors) from the center of each sphere creates our space-frame trusswork.


Microwave data gathered by the WMAP satellite indicates the
Universe may be in the shape of a 'chiral' Dodecahedron -
a twelve sided polyhedron with pentagonal symmetry.

So ... My first question is how does the 6-symmetry space-frame superclusters matrix
relate to the 5-symmetry dodecahedral universe 'shape' (not proven ... still hotly debated)!
hmmm ... the spheres pack 12-around-1 and the Dodeca has 12 faces.
Just an observation ...



More about the possibly dodecahedral universe here -
http://news.nationalgeographic.com/news/2003/10/1008_031008_finiteuniverse_2.html