B Why do subatomic particles change what they do when observed?

curiosity1
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Measurement problem of quantum mechanics
Why do subatomic particles change what they do when observed? Does it matter who is doing the observing? What happens if a non-sentient robot does the observing? How does that compare with a sentient human doing the observing? Thank you.
 
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curiosity1 said:
Summary: Measurement problem of quantum mechanics

Why do subatomic particles change what they do when observed?
The dynamic quantity being measured does not have a definite value until a measurement is made.

After the measurement, the state of the particle "collapses" to an eigenstate of the observable that was measured.

That's essentially an axiom of QM. It's like a law of nature, so there is no more fundamental explanation.
curiosity1 said:
What happens if a non-sentient robot does the observing? How does that compare with a sentient human doing the observing? Thank you.
It makes no difference what makes the measurement. Most if not all, measurements are made by measurement devices and human beings only look at the output from those.
 
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Thank you very much for your quick and helpful reply.
 
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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