2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/138609In this paper we show that the nontrivial fundamental group $π_1 SO(3) ={\Bbb Z}_2$ for the group SO(3) of global proper rotations of a four-dimensional Euclidian space (when a spin structure is introduced preliminarily in that space) implies always fermions as global SO(3) vortices, while bosons can be reduced to trivial lines (contracted into a point) in the SO(3) group space.26 pages, 7 eps.figures, LaTeXHigh Energy Physics - TheoryGeneral Relativity and Quantum Cosmologytext