  Based on previously published alternative reflections on gravitation,
additional conclusions concerning anomalous gravitational effects in the
universe are derived. For systems with spherical mass distribution and high
central density of the luminous matter, abnormal increases in the gravitational
potential towards the centers of these systems are derived. These anomalous
increases are calculated on the basis of the amount and distribution of the
observed luminous matter. For spiral galaxies, the calculation yields the
astonishing result that the anomalous part of the gravitational potential is
not produced by the large mass of the spiral system but by the small mass of
the central bulge. A noticeable anomalous increase can only be expected close
to the center, e.g. in the innermost region with a diameter on the order of
only 1 pc in a bulge with a radius of 500 pc. Experimental observations are
cited reporting such anomalous gravitational effects in the four spherical
systems considered: globular star clusters, the bulges of spiral galaxies,
elliptical galaxies, and clusters of galaxies. Conventionally, on the basis of
Newtonian Mechanics and the amount of luminous matter, these effects are
unexpected. They are most commonly explained by assuming the existence of
appropriate large black holes or a sufficient amount of dark matter.
