Figure 8. In Figure 8, the X, Y plane is perpendicular to the photon's velocity, and the photon has a velocity in the positive Z axis direction. The part of the coordinate system that is perpendicular to the photonic event line is similar to matter's reference frame.  In Figure 8, the X, Y plane is a two-dimensional space that has an infinitely fast here-now and has a distance-time with a speed c.