We propose a tabletop experiment—a threshold-based detector for anomalous gravitational effects that could arise from a hypothetical coupling between quantum branches. A hollow graphite microsphere containing a single Rydberg atom is placed on a room-temperature liquid metal surface with high surface tension. The atom is driven into a deliberately non-stationary configuration—metaphorically, like a die balancing on its edge—by a calibrated broadband magnetic pulse. If an anomalous force exists and overcomes the surface tension barrier, the sphere physically detaches—a discrete, unambiguous event. We demonstrate that standard atomic gravity, environmental noise, van der Waals forces, and Joule heating cannot cross the threshold. Casimir forces are controllable. Surface temperature is monitored. Zeeman-state calibration ensures reproducibility. High-speed imaging captures impulsive detachment. Five null tests ensure signal validation. This protocol is feasible with current technology at room temperature. Plain Language Summary: This paper asks: if other worlds exist, could an invisible force from those worlds pull a tiny sphere off a liquid metal droplet? Our answer is yes—and that event would be a candidate signal requiring further investigation.