The Universal Law of Life Systems: Entropy Resistance and the Nature of Living Systems

The lack of a universal, physically grounded definition of life remains a critical gap across biology, astrobiology, and artificial intelligence. Traditional definitions often rely on biochemical functions or evolutionary heuristics, offering limited applicability across substrates, scales, and domains. This paper introduces a general law: a system is alive if and only if it sustains a positive rate of entropy resistance. In the quantum regime, this is formalized as Rq (t) =−d/dt Tr[ρ(t) ln ρ(t)] >0, where ρ(t) is the system’s density matrix and the trace yields the von Neu- mann entropy. The proposed condition is substrate-independent, operationally measurable, and falsifiable. This formulation provides a unifying thermodynamic criterion for terrestrial biology, synthetic organisms, coherent quantum states, and potential extraterres- trial systems—without invoking replication, metabolism, or evolution. It reframes life not as a biological artifact, but as a distinct physical regime that persistently resists informational and entropic collapse. Life, under this framework, is not explained by physics. It is a phase of physics, defined by its sustained resistance to the default trajectory of the universe.