Made me think of this. Maybe when they were doing the experiment, a gravitational wave happened and they somehow reflected it?

> Thin superconducting films are predicted to be highly reflective mirrors for gravitational waves at microwave frequencies. The quantum mechanical non-localizability of the negatively charged Cooper pairs, which is protected from the localizing effect of decoherence by an energy gap, causes the pairs to undergo non-picturable, non-geodesic motion in the presence of a gravitational wave.

https://arxiv.org/abs/0903.0661