Volume 5 provides a detailed mathematically philosophical study of the kinematics, thermodynamics, and topological aspects of light-speed travel at variously infinite Lorentz factors.
The book further explores faster-than-light travel in some fascinating detail especially velocities of travel that would be ever so slightly faster than light so as to not result in causality issues and remain true to the spirit of Special Relativity.
Numerous degrees of kinematic freedom are explored for which each degree of freedom is associated with a light-speed component of motion.
The author provides much whimsical content affirming that inertial travel at the speed of light may enable vastly more far-ranging travel itineraries than any superluminal warp drives or wormhole travel may enable.
Additionally, Volume 5 provides numerous examples for how light-speed or almost light-speed travel may be obtained.