Bulk Flows

Observed bulk flows — coherent motions of galaxies and clusters over scales of several hundred megaparsecs — consistently exceed the velocities that ΛCDM's density perturbation spectrum can drive. The standard model predicts that peculiar velocities on scales above ~100 Mpc should be very small because there is insufficient gravitational potential gradient to accelerate large volumes coherently. Successive Collision Theory provides a physically direct origin: the collision between two spacetime pockets deposited not only thermal energy but a net momentum vector aligned with the collision axis. This imprinted a preferred direction of flow across the entire debris field. Angular momentum inheritance from the collision geometry ensures that bulk motion persists coherently across the scales set by the original pocket intersection, which vastly exceeds the gravitational coherence scale that inflation-seeded perturbations can produce.

In the SCT framework, bulk flow magnitude and direction encode the geometry of the original collision: higher-speed flows trace the primary momentum deposition axis, while the flow's decay profile with increasing distance from the collision center encodes the original pocket size and relative velocity. Because the KBC supervoid places us inside the evacuated interior of a collision pocket, galaxies surrounding the void's shell are being drawn toward the dense rim by gravitational potential gradients that are coherent across the full ~300 Mpc supervoid diameter. This gravitational infall toward the surrounding overdense shell manifests as the observed bulk flow. SCT thus unifies the supervoid, the Hubble tension's spatial component, and anomalous bulk flows as three observational signatures of the same underlying collision-pocket geometry.