2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/34558This study looks at motion of particles using mathematical methods of chronometric invariants (physical observable values in General Relativity). It is shown that aside for mass-bearing particles and light-like particles "zero-particles" can exist in fully degenerated space-time (zero-space). For a regular observer zero-particles move instantly, thus transferring long-range action. Further we show existence of two separate areas in unhomogeneous space-time, where observable time flows into future and into past, while this duality is not found in homogeneous space-time. These areas are referred to as our world, where time flows into future and as the mirror Universe, where time flows in past. The areas are separated with a space-time membrane, referred to as zero-space, where observable time stops.47 pages, published as "Particles here and beyond the Mirror" Editorial URSS, Moscow, 2001. Version 4: final design in formulasGeneral Relativity and Quantum Cosmologytext