As I understand, a Double slit experiment produces interference pattern or two broad distributions on the detector based on observation.
Does delayed choice quantum eraser produces the same patterns ?
I think the question it comes down to is: when we have a double slit experiment, can we look at the pattern on the screen and tell from it if the observer is present or not? From the videos I got impression like "O, there is an interference pattern, means no one is watching"; "No interference pattern = someone is watching/measurement is being made". But why does it sound like in case of delayed choice quantum eraser, the screen will look the same no matter what.
My impression is that the quantum eraser is also a double slit experiment, but with entanglement part that effectively makes a copy of the information.
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