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    I Would this experiment disprove that consciousness causes collapse?

    I am not familiar with Quantum Decoherence, but I find it difficult to treat macroscopic states like; alive and deal on the same footing as quantum states that describes position, time, momentum and energy. Like in a recent paper published by Frauchiger and Renner, they described states like...
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    I Is the Compton scattering angle related to the incident energy?

    So, is there a way to represent Compton scattering using Feynman diagram?
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    I QM Assumptions Regarding Entanglement Properties

    I made a graph representing local hidden variables (HV) and Bell`s inequality. Each plan of HV is represented by a shade of gray color. This can be interpreted as the number of particles emitted from the source following the plan protocol or by the proportion of the particles following the...
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    I Is the Compton scattering angle related to the incident energy?

    The Compton equation determines the shift of the wave-length of the scattered photon as a function of the ##cos\theta## of the scattered photon. It does not depend on the energy of the incident photon. With some manipulation using the equations of conservation of the momentum and energy, one...
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    I Will a uniform magnetic field be considered as measurment?

    Although this is excursion from the main point of the thread, I still think the first probability must be ##P(a|\psi)=|\langle a|\psi \rangle|^2## not ##|\langle a|\psi \rangle|## . Example, spin-1/2 has the state ##|\psi \rangle=\frac{1}{\sqrt2} |up \rangle+\frac{1}{\sqrt2} |down\rangle## So...
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    I Will a uniform magnetic field be considered as measurment?

    No great problem, just I am not familiar with this expression of probability. The probability is, in general, written in term of a value over the sum of all values representing the system. So the sum should be in the denominator. And the value in our case is the square of the projection of the...
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    I Will a uniform magnetic field be considered as measurment?

    Look up here under "Discrete, nondegenerate spectrum" https://en.wikipedia.org/wiki/Measurement_in_quantum_mechanics
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    I Will a uniform magnetic field be considered as measurment?

    I thought it is in the form ##\frac{\mid\langle a,\beta|\rho\rangle\mid^2}{\sum \mid\langle a_k,\beta|\rho\rangle\mid^2}##
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    I Will a uniform magnetic field be considered as measurment?

    Why there is a sum? is this the probability to find the system in the state ##|a,\beta \rangle##?
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    I Will a uniform magnetic field be considered as measurment?

    I understand that the gradient of the field inside SG-device applies a force on the particle and separate the beam with particular spin in one direction from all other beam with different spin in the other direction. But, does it mean the time evolution operator I write above, with the gardient...
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    I Will a uniform magnetic field be considered as measurment?

    In a previous thread about an entangled pair, I proposed a thought experiment where one particle goes into a uniform magnetic field and the other set free. I remember you told me that the one goes into the field emits photon if it is anti-parallel to the field and this can be considered a type...
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    I Will a uniform magnetic field be considered as measurment?

    But if the particle goes inside a SG-device, it is measured and we get a real value eigenvalue. There is a gradient of the magnetic field inside the device and the time evolution operator of SG-device is ##e^\frac{-i\gamma(B_0+\nabla B.z)St}{\hbar}##. So how does this complex value operator...
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    I Will a uniform magnetic field be considered as measurment?

    Sorry, but it is not clear for me the difference. How can the measurement be represented mathematically in QM other than eigen value problem?
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    I Will a uniform magnetic field be considered as measurment?

    What is then the difference between the collapse of the state and acting on it by an operator? The operator is a matrix and the state is a vector, so acting on a vector by a matrix given a value times the vector.
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    I Will a uniform magnetic field be considered as measurment?

    But ##exp \frac{-iHt}{h} = exp \frac{i\gamma B_0 S_z t}{h}##. Now ##S_z## should act on l+> and l-> which is a measurement process.
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    I Will a uniform magnetic field be considered as measurment?

    My question is, why the general state is still general? The unitary operator is like any other operator, once acts on the system, the state should collapse into the one with a definite value not a state of superposition of base vectors!
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    I Will a uniform magnetic field be considered as measurment?

    Any pure state of spin-1/2 particle can be represented by a superposition of spin up and spin-down relative to an arbitrarily direction. lw>=a l+> + b l-> where a^2+b^2=1 If there is no magnetic field, the measurement of the spin is random and we get 50-50 chance to be spin up and spin down...
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    I Entanglement, magnetic field and conservation law

    So what is the true mathematical description of the quantum state interacting with the field? will this be under quantization of EM field?
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    I Entanglement, magnetic field and conservation law

    Thank you, yes I misunderstood the act of measurement as you said. I thought the outcome of that interaction, which is always spin-up, is the result of the measurement. Just another point related to the interpretation of the meaning of the entangled state. You have pointed that the emission of...
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    I Entanglement, magnetic field and conservation law

    The relative time reflects the order of measurement in the frame of reference of Alice-Bob. Even in the classical entanglement experiment, when Alice measures her particle first, the wave-function collapses and the state of Bob particle is reduced to the one with opposite spin along the same...
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    I Entanglement, magnetic field and conservation law

    No, the position of the uniform magnetic field is before the location of Alice which means Bob can not measure his particle before Alice particle already passes though B0. See the picture.
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    I Entanglement, magnetic field and conservation law

    But Stern-Gerlach device applies a non-uniform magnetic field.
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    I Entanglement, magnetic field and conservation law

    But what does "end of entanglement" mean? Can passing the particle through the Stern-Gerlach device be considered as another sort of interaction? Why does not the Stern-Gerlach device end the entanglement and passing through B0 does?
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    I Entanglement, magnetic field and conservation law

    I am not sure that I fully understand even the basic aspects of the Quantum measurement and entanglement but I just came across this thought experiment and I wish to resolve it. In a setting of two entangled spin-1/2 particles, suppose that Alice applies a uniform magnetic field ##B_0## along...
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    I Conceptual catch in EPR

    But where in Bell`s inequality, a simultaneous reality of non-commuting observables is measured? My understanding is; Bell`s-like experiments only test whether an objective reality with particles have a predefined physical values before the measurement determined by the hidden variables exists...
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    I Conceptual catch in EPR

    Now I come to understand this statement in the following way. 1) EPR showed that the rules of quantum mechanics and the criterion of reality can not be both true which implies that quantum mechanics is not complete theory. 2) Bell`s type experiments confirmed that the rules of quantum mechanics...
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    I Conceptual catch in EPR

    I understood that EPR ruled out the possibility of having the rules of quantum mechanics consistent with the Criterion of Reality (COR) as they defined, because if it is consistent, a contradictory will ensue, therefore they concluded that quantum mechanics can not be complete. So long as this...
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    I Conceptual catch in EPR

    You confused me so much. You said that (A and -B) imply C and (A and -B) imply -C right? First let us agree about C. according to your post #15, you said: I know that EPR showd that (A and -B) imply C. now I need to know how did they show (A and -B) imply -C which translates to the statement I...
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    I Conceptual catch in EPR

    Why math forums :) if I am questioning logical validity of statements that have physical meaning. I rather prefer to start another thread here in this forum asking the following: did EPR show in their paper that: the rules of quantum mechanics and the definition of the physical reality that...
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    I Conceptual catch in EPR

    I do not understand why you mentioned that (A and -B) implies C?. I agree that only A implies C and (A and -B) imply -C. I then applied truth table for rigorous analysis, (I used ">" to mean: implies and "^" to mean "and". When A implies C and (A and -B) implies -C, then this does not mean that...
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