[absolutelynobo]

You can easily break Stern-Gerlach by spreading the “measurements” super far apart, so far that interactions with other matter destroys the effects of the first measurements.

It’s incredibly easy to lose coherence in other quantum experiments as well.

[plaguepilled]

I don't doubt that quantum experiments like Stern Gerlach are sensitive! :)

I probably should have specified: can you break stern Gerlach specifically by introducing isometry and the constructing an experiment that allows the particle to move through an expanding spacetime?

[absolutelynobo]

If you can expand spacetime locally, why not?