{"knowledge_schema": {"broad_category": "Physics \u2192 Gravitation \u2192 Relativity", "refinement": "This problem examines the implications of relativistic effects on gravitational fields and their interaction with mass in a system of two bodies in relative motion.", "specific_scope": "The focus is on how the center of gravity of one mass appears to shift from the reference frame of another mass due to relativistic effects and the propagation of gravitational fields.", "goal": "Identify which assumption about gravity leads to the observed shift in the center of gravity of mass 2 from mass 1's perspective."}, "summary": "This problem involves understanding the relativistic effects of gravity on two masses in motion relative to each other. It requires analyzing how gravitational fields propagate and interact with mass, particularly how these interactions can lead to observable shifts in the center of gravity from different reference frames. The goal is to determine which assumption about gravity would necessarily result in the center of gravity of mass 2 appearing shifted in the direction of its motion from mass 1's reference frame."}