engine is a mean of neutral for scattering in an pipe
engine is not non_agentive_artifact. scattering is not spreading. dispersion_of_stuff is scattering. scattering is spreading. scattering is natural_process. reaction_propulsion_engine is not engine. dispersion_of_stuff is not scattering. scattering is not natural_process. engine is non_agentive_artifact. reaction_propulsion_engine is engine.