Young and old galaxies coexisting in the observable universe: How central black hole mergers reset the galactic clock

Recent observations from the James Webb Space Telescope (JWST) have revealed massive, mature galaxies at redshifts z > 10, corresponding to just 300-500 million years after the Big Bang according to standard ΛCDM cosmology. These galaxies possess stellar populations, supermassive black holes (SMBHs), and metallicities that appear impossible to form in the available time. We propose that these "impossibly young" galaxies are not primordial structures but rather the products of recent galactic rejuvenation events caused by SMBH mergers occurring throughout cosmic history. Building upon the Bilobular Collision Model (BCM) presented in Díaz ( 2025, DOI: https://doi.org/10.5281/zenodo.17948685 ), which proposes that the observable universe formed ~13.8 Ga ago from the head-on collision of two ultra-massive black holes (Parent Lobes) at relativistic velocities, this paper introduces a fractal hierarchy of collisions operating at multiple scales: Scale 1 (Primordial) - Collision of Parent Lobes; Scale 2 (Galactic) - SMBH mergers creating galactic rejuvenation; Scale 3 (Stellar) - Compact object mergers producing heavy element nucleosynthesis. We demonstrate that Scale 2 events—mergers of SMBHs with masses 10⁸-10¹⁰ M☉—release energies of 10⁵⁵-10⁵⁷ J, sufficient to trigger explosive star formation (500-2,000 M☉/yr), eject metal-rich gas at velocities 0.1-0.5c, create morphologically chaotic structures, and produce the appearance of "youth" regardless of actual cosmic epoch. This framework eliminates the need for dark energy by explaining differential recession velocities through mechanical ejection dynamics (center ejected slowly, periphery ejected rapidly—analogous to compressed spring release or water droplet crown splash). It also eliminates the need for dark matter by attributing flat galactic rotation curves to collective disk gravity plus collision-imparted inertia. We provide six falsifiable predictions with detailed observational protocols, timelines, and budgets totaling ~$310M over 10 years. The highest-priority prediction involves detecting "relic galaxies"—structures from the previous cosmic cycle with ages >13.8 Ga that were not absorbed during the Parent Lobes' accretion phase. Part of the Proyecto A.D.A. (Architecture of Survival) series - Preprint 24. A chapter of: Survival Architecture: https://play.google.com/store/books/details?id=epWgEQAAQBAJ Arquitectura de la supervivencia: https://play.google.com/store/books/details/Alejandro_D%C3%ADaz_Aldana_Arquitectura_de_la_Supervive?id=DpCgEQAAQBAJ