  This paper is a significantly expanded version of gr-qc/0306066. It discusses
the geometric properties of the so called holographic solution, an exact,
spherically symmetric solution to the Einstein field equations with zero
cosmological constant. The holographic solution can be regarded as the simplest
solution of the field equations including matter. Its interior matter-density
follows an inverse square law: e = 1 / (8 pi r2). The interior principle
pressures are P_r = - e in the radial direction and P_tan = 0 in the tangential
direction. This is the equation of state of a radial arrangement of strings.
The interior string type matter state is densely packed, each string occupying
a transverse extension of exactly one Planck area, and bounded by a membrane
consisting out of tangential pressure. The membrane's energy density is zero,
as expected from string theory. Despite its simple structure, the results that
can be derived from this solution are far from trivial. It is not possible to
give a fair account of all relevant results in a 20-line abstract. The reader
is referred to the abstract in the paper, which summarizes some of the more
important results. The author appreciates any comments, critique or suggestions
of new material.
