Entropy increases from past to future, while the microscopic laws of physics are time-symmetric. To recover the observed thermodynamic arrow, ΛCDM has to assume the universe began in an extraordinarily low-entropy initial state at the Big Bang singularity (Penrose 2010; Carroll & Chen 2004). The model offers no mechanism for why this boundary condition should hold, treating the past hypothesis as an unexplained input.
The standard model assumes a t = 0 hot dense singular beginning. Once that beginning is committed to, the question of why entropy was minimal then becomes unanswerable from within the model. The arrow of time is a boundary-condition problem with no physical origin in the framework itself.
SCT replaces the hot-dense-center with a superluminal collision in an eternal infinite manifold. From this single change, the t = 0 singular boundary condition disappears (P1, P28). Time has no beginning, so there is no special initial state whose low entropy needs to be explained as an external input. What remains is the question of where the macroscopic arrow comes from in our cosmological epoch, and SCT supplies a concrete mechanism rather than a postulate.
Every gravitationally bound system in the cosmic hierarchy is undergoing slow orbital decay through three-body ejection and dynamical friction (P14). This is intrinsically irreversible statistical evolution under standard GR — well-bound stars get more bound, loosely bound stars get ejected, and the mesh of overlapping potential wells progressively weakens (P15, P16). The cumulative macroscopic effect is the cosmological arrow we observe: matter clusters into denser concentrations, gravitational binding energy redistributes, the Λ_eff(x,t) ratio evolves under P17, and the observable universe acquires its time-asymmetric character from this hierarchy of irreversible processes (P18).
The thermodynamic arrow inside our patch then sits on top of this gravitational arrow as a natural consequence: stellar nucleosynthesis, photon emission into a sky that grows progressively darker as expansion drains the radiation density, biological evolution. None of these requires a special low-entropy initial state. They require only that the local cosmological era is mid-cycle in an eternal sequence of collision-and-relaxation events (P26, P27, P28), with mesh dissipation providing the persistent driving asymmetry. There is no boundary condition to fine-tune because there is no boundary.
Detection of measurable mesh-dissipation reversibility in any gravitationally bound system (regions where orbital decay statistically reverses, or where dynamical friction transfers energy into bound orbits rather than ejecting) would refute the geometric origin of the arrow. Standard N-body simulations and pulsar-timing observations provide the precision needed to test this.