Help a Quantum Noob with the Wavefunction Collapse?

Meddle
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If matter goes from a superposed state to a collapsed state when measured, how did scientists see the interference pattern in the double slit experiment, doesn't the surface that the photons hit after passing through the slits count as a measuring device?

Also, is there any updated Interpretation of Quantum Mechanics aside from the Copenhagen Interpretation that doesn't conflict with paradoxes like "Schrodinger's Cat"?
 
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Wave function collapses into the eigen state of the measurement operator. If you try to detect which path the particle took, these are your eigen states. For the detector showing interference patterns, the eigen states are completely different. That's the measurement of particle's position at the screen, rather than at the slits. Different operators, different eigen states, different collapse.

But yeah, the state still does collapse due to the measurement. It's just that every state to which it collapses still involves particle going through both slits.
 
Meddle said:
If matter goes from a superposed state to a collapsed state when measured, how did scientists see the interference pattern in the double slit experiment, doesn't the surface that the photons hit after passing through the slits count as a measuring device?

Also, is there any updated Interpretation of Quantum Mechanics aside from the Copenhagen Interpretation that doesn't conflict with paradoxes like "Schrodinger's Cat"?

One wastes less intellectual energy if one avoids collapse-based interpretations of QM.

See my response #4 in this thread:

https://www.physicsforums.com/showthread.php?t=460523
 
Except, you know, things like Quantum Eraser kind of break that concept.
 
Insights auto threads is broken atm, so I'm manually creating these for new Insight articles. Towards the end of the first lecture for the Qiskit Global Summer School 2025, Foundations of Quantum Mechanics, Olivia Lanes (Global Lead, Content and Education IBM) stated... Source: https://www.physicsforums.com/insights/quantum-entanglement-is-a-kinematic-fact-not-a-dynamical-effect/ by @RUTA
If we release an electron around a positively charged sphere, the initial state of electron is a linear combination of Hydrogen-like states. According to quantum mechanics, evolution of time would not change this initial state because the potential is time independent. However, classically we expect the electron to collide with the sphere. So, it seems that the quantum and classics predict different behaviours!
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