Reactionless propulsion is forbidden in closed systems by momentum conservation and Noether's theorem. However, many real-world systems exhibit motion that appears reactionless at the local or experiential level while remaining globally momentumconserving. This paper introduces the Externally Reacted, Internally Silent (ERIS) Motion Model, formalized under the Constraint-Driven Physical Realization Framework (CDPRF). The model distinguishes between global momentum exchange and internal force experience, demonstrating how propulsion systems may achieve reactionless-perceived motion without violating physical laws. Applications are discussed in aerospace propulsion, vehicle dynamics, and biomedical motion systems.
PRABIN KUMAR (Wed,) studied this question.