... single point I+, namely at future in nity. Allincoming photons have their origin on the segment−(script I−or ‘scri minus’),lightlike past in nity, and will run into the coordinate singularity ... 1. (1.63)Then ingoing null geodesics are described by v = constant, outgoing onesby u = constant, see figure 1.8. We define ingoing Eddington–Finkelsteincoordinates by replacing the ‘Schwarzschild ... the˜t-axis.All outgoing photons arise from the coordinate singularity and cease on the line+, lightlike future in nity (‘scri plus’). The entire spacelike in nity is mappedinto the single point I0.Now,...