This work develops a testable framework in which tau neutrinos couple to a ternary structure of time, extending oscillation physics beyond the binary arrow-like conception of temporality. The model introduces a three-state temporal basis—past, future, and simultaneity (imaginary-phase channel)—and formulates an effective Hamiltonian that preserves unitarity and no-signaling. Distinctive experimental signatures are predicted, including odd-in-(L/E) asymmetries, localized tau excesses, and non-sinusoidal oscillation microstructures, all within reach of current or near-future neutrino facilities.Beyond phenomenology, the ternary-time operator maps to ternary logic computation (TRILUX), imaginary-phase hardware channels (IPLU), and novel cryptographic and energy-system applications. The framework thus bridges particle physics, AI hardware, quantum cryptography, and sustainable technologies, while also reframing causality as a bidirectional ternary resonance with implications for philosophy and civilization. KEY WORDNeutrino oscillations – Tau neutrinos – Ternary time retrocausality – Effective Hamiltonian – TRILUX (ternary logic) – IPLU (imaginary-phase channel) – AI hardware – Quantum cryptographic causality – T-no-signaling – Civilizational impact Author KEI 白石(first author) mail:keixaide@varuna.jp AIDE (Co-author or AI collaborator)