In this paper, we study the gravitational field generated by a
material straight line around itself. We show the simplicity of the
studied field, and we show its relation with the arc of half circle. We
discussed also the subject of attracting two
spacious straight lines,
and we show the absence of relation between the mutual force and
the distance.
Also we study the field generated by a ray, where we present the
different formulas for this field, and we show its geometrics
properties, and its relation to a circular arc sees through it.
Also studied the previous field lines, and we show that it are
parabolas, and we appear by different ways that the equivalent
surfaces are parabolic surfaces of revolution.
