Distance-ladder splits refer to internally consistent sub-implementations of the ladder yielding statistically distinct H₀ values and distance moduli even before comparing to CMB (Freedman 2019; Riess 2022; Kenworthy 2022). Cepheid-SN vs TRGB-SN, optical vs near-infrared SN standardization, star-forming vs passive host selection, all show split bifurcations of the inferred H₀ at the few-percent level.
The standard model assumes self-consistent sub-ladders must converge on one universal H₀ once stellar-physics systematics are controlled. Persistent splits force the model to invoke method-dependent systematics affecting several rungs in different ways, or to acknowledge that the assumed single FRW background is incomplete.
SCT replaces the hot-dense-center with a superluminal collision and the thermalized debris field. From this single change, distance-ladder splits are direct signatures of host-environment heterogeneity produced by cascade-seeded structure evolution. Pre-existing matter from prior cascade cycles (P25, P28) seeded different host populations with genuinely different stellar physics; different calibrators (Cepheids, Miras, TRGB, SBF) probe different stellar-population states inherited from those distinct chemical-mixing histories.
Angular-momentum inheritance (P31, P32) further bifurcates the host populations: spiral hosts (with high inherited J from grazing collisions) follow different rotation-curve and stellar-formation tracks than elliptical hosts (with low inherited J from head-on collisions). Hereditary-time (P10) gives frame-tree depth variations between cluster-environment hosts and field hosts that propagate into the calibration zero-points. Each split traces a real physical bifurcation, not a calibration error that better data will erase.
The bifurcated H₀ values converge on the SCT/CAR consensus 70.4 km/s/Mpc (Paper 16) when the host-environment and stellar-population corrections are applied. The same M5 framework that resolves the broader ladder-coherence problem (recid 52) accounts for the splits as host-population signatures. Critically, splits do not diminish with improved data quality — they should sharpen. There is no need for unrecognized compensating systematics in multiple sub-ladders simultaneously.
If precision next-generation distance-ladder surveys find that splits collapse to zero with improved stellar-physics modeling (Cepheid-SN and TRGB-SN converging to the same H₀ at the 0.5% level after corrections), the M5 host-population-bifurcation explanation is refuted. The signature SCT prediction is that splits sharpen with better data because they trace real physical heterogeneity rather than measurement noise.