2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/211738Recently [arXiv:astro-ph/0612155] we presented a formal mathematical proof that, contrary to a widespread misconception, cosmological expansion cannot be understood as the motion of galaxies in non-expanding space. We showed that the cosmological redshift must be physically interpreted as the expansion of space. Although our proof was generally accepted, a few authors disagreed. We rebut their criticism in this Note.5 pages, 2 figures, submitted to Acta AstronomicaAstrophysicstext