I hope I've searched the forums thoroughly enough, I didn't find a similar question. I'm wondering about the specifics of the speed of the information on change in B of the solenoid between the two paths in a double-slit setup, one large enough where relativistic speed effects are within a measurable range. Obviously I'm assuming ftl communication is impossible. For instance, you can move the solenoid some distance from the slits, as long as it cuts through the surface enclosed by the paths. But even if it's close, where would one observe the "starting point" of the change in the magnetic flux (i.e. the delay between the change in B and the change in the interference pattern)? At the slits, or from where the solenoid is located, basing on what? And is that still compatible with the non-locality of the phenomenon? Thanks.