Quantum Echoes

in spaces surrounding the site of an FTL drive cascade, certain "imprints" in the environment before and after the cascade will appear, almost as a hallucination. They can range from a single person to the entire interior of a ship. They are not alive, aware, nor can they be interacted with; they simply "repeat" the same point in time until the residual cascade dissipates. Scientific data and personal accounts are all over the place and peppered with superstition. Some data suggests that objects and areas of great sentimentality or moments of high emotional intensity are more likely to be repeated by a quantum echo, other data suggests it makes no difference. Some data suggests bringing "haunted" salvage from the site of a quantum echo will bring the quantum echoes with it, or "curse" the ship, other data suggests no such thing.