To solve the dilemmas of the "propagator paradox" and "spacetime geometrization" in existing physical theories regarding the microscopic mechanism of force, this paper, based on the framework of information dynamics evolution theory, clarifies the nature of force and establishes a unified logical system. Firstly, it argues that force is not an independent entity but a causal inertial state evolution emerging from symmetry breaking through global perception and momentum state exchange of evolutionary carriers under Planck spacetime snapshots. Then, it proposes four core mechanisms to support this conclusion, including the cancellation of resultant velocity principle, equivalence of force and velocity, delay-free and propagator-free interaction, and potential space borrowing and returning mechanism. Finally, it unifies the four fundamental forces into four encapsulation and perception interaction protocols derived from the double c coding and symmetry breaking of momentum units, and clarifies that spacetime is an emergent relational quantity, force is a momentum cooperative trend, and the universe is a precisely cooperative evolution system under discrete causal states.
bo xiao (Wed,) studied this question.