The Giant Arc spans 3.3 billion light-years of Mg II absorbers and galaxies at z of 0.8, detected at over 4σ (Lopez et al. 2021), three times the ΛCDM ceiling on genuine structures. The Big Ring sits in the same redshift shell a few hundred Mpc away. Gaussian initial conditions plus gravity assign coherent gigaparsec objects essentially zero probability, so the model must call each confirmed giant a pattern-finding mirage.
ΛCDM grows all structure from a Gaussian random field whose coherence cannot reach gigaparsec scales in the age available: the largest allowed genuine objects top out near 370 Mpc. The model has no formation channel for a 1 Gpc arc, so observation and theory can only be reconciled by impeaching the observation.
SCT replaces the hot-dense-center with a superluminal collision cascade whose first and largest stage deposited structure at the scale of the colliding pockets: characteristic size Λ_max of about 2 R_pocket, near 5 Gpc, in ring-and-filament morphology from shock-compressed shells, elongated features along the collision axis and ring structures perpendicular to it (P55, P33, P34). A 1 Gpc arc at z of 0.8 is not an anomaly in this framework; it is the predicted class, sitting comfortably inside the deposit spectrum that ΛCDM's ceiling forbids. The detection significance stops being a problem to explain away and becomes a measurement of the first collision stage.
The Arc-Ring adjacency is the framework's signature detail: one shock geometry produces elongated structures along the axis and rings perpendicular to it, so finding both morphologies within a few hundred Mpc at the same epoch reads as two faces of a single first-stage feature rather than independent flukes whose probabilities multiply against ΛCDM. Statistical homogeneity survives untouched, because it is a property of the thermalized average (P6) while the giants are the rare countable scars of deposition.
This is the same first-stage geometry behind the homogeneity-scale debate and the CMB low-multipole anomaly family. There is no need to impeach pattern-finding algorithms that keep finding the same class of object.
The registered kill: DESI and Euclid spectroscopy through the Arc volume showing the structure dissolves in three dimensions, a chance projection of unconnected absorbers with no coherent overdensity, removes this confirmed instance, and the deposit class fails if the full inventory dissolves with it. The spectrum is bounded from above as well: coherent structures significantly exceeding Λ_max of about 5 Gpc would break the pocket-scale deposit limit that makes the prediction quantitative.