> By toggling the switch on and off, the researchers could effectively cancel the rotation signal at will, which also allowed them to extend the stability of their large apparatus. "We have basically tricked the light into thinking it's in a non-rotating universe," says Silvestri.

"Experimental observation of Earth's rotation with quantum entanglement" (2024) https://www.science.org/doi/10.1126/sciadv.ado0215

Sagnac interferometer: https://en.wikipedia.org/wiki/Sagnac_effect

What if we consider the quantum vacuum, with its virtual particles and fluctuations, as a modern version of the ether? In that case, could the rotation of the Earth interact with this "quantum ether" and influence the propagation of the entangled photons in the Vienna experiment? It's kind of like the idea of frame dragging in general relativity, where the rotation of a massive object affects the surrounding spacetime geometry.

Of course, this is just speculation, and any theory involving an ether-like concept would need to be consistent with all the experimental evidence supporting relativity and quantum mechanics. But I think it's still worth exploring these ideas, as they could lead to new insights into the nature of space, time, and gravity.

Or maybe this could help with tracking time more accurately? Hopefully someone with knowledge can chime in with what this means in practice.

I’ve been wondering about sending photons away from earth and having their paths bend due to gravity (and later have them interfere). That would be interesting because GR would be involved.