That said, I can think of an experiment that at least doesn’t throw a compilation error. On a quantum computer, simulate different people in different timelines. If onlookers paying different amounts of attention to different of those timelines pumps amplitude into those timelines, and I see no reason it should, this is straightforwardly measurable. People aren’t ontologically basic, so the same pumping should already warp the lesser calculations we do today.
That said, I can think of an experiment that at least doesn’t throw a compilation error. On a quantum computer, simulate different people in different timelines. If onlookers paying different amounts of attention to different of those timelines pumps amplitude into those timelines, and I see no reason it should, this is straightforwardly measurable. People aren’t ontologically basic, so the same pumping should already warp the lesser calculations we do today.