This book addresses the latest advances in general relativity research, including the classical world and spinor formalisms; keys to understanding gravity; the continuum mechanics of space-time; new evidences on matter without energy-stress tensor; a new approach to study gravitational stability of the solutions to the Einstein equations; Mond theory; polynumbers field theory; the algebra, geometry and physics of hyperland; S2-like star orbits near the galactic center in RN and Yukawa gravity; geodesic analysis in multidimensional gravity models; and the collapsing of general relativity and the singularity in the event of the Big Bang and black holes.