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Sure, but many people do think it does, and such an interpretation is totally compatible with QM. The Schrödinger equation and wave function collapse are not c

Sure, but many people do think it does, and such an interpretation is totally compatible with QM. The Schrödinger equation and wave function collapse are not compatible. Maybe they could be integrated in some theory, but that will need a lot of additional explaining when and how the evolution changes between being unitary and non-unitary. But it's irrelevant because physics isn't about what things "seem like to humans", it's about what we actually measure and how to create theories that explain and predict it. You are still missing my point. Quantum mechanics in general and entanglement in particular are arguably hard to understand because they are unintuitive. If all that was going on were some non-local interactions, than entanglement would not be hard to understand because non-local interactions are intuitive to us because we are familiar with things that look like non-local interactions to us. Now turn this argument around. We are still having a lot of trouble making sense of quantum mechanics, therefore it seems unlikely that non-locality is at the core of quantum mechanics, because if it was and would explain everything, than it would not be so difficult to grasp quantum mechanics because we have an intuition for non-local behavior. This is obviously no rigoros argument but it was also never was meant to be one.

bowsamic 3y ago
> The Schrödinger equation and wave function collapse are not compatible. They don't need to be because they describe totally different phenomena. > Maybe they could be integrated in some theory, They already are integrated into the theory of quantum mechanics. Take a look at the postulates of quantum mechanics again, one of the postulates is unitary evolution through time, another is non-unitary collapse with measurement. All the experimental results of quantum mechanics are compatible with those postulates. > Quantum mechanics in general and entanglement in particular are arguably hard to understand because they are unintuitive. If all that was going on were some non-local interactions, than entanglement would not be hard to understand because non-local interactions are intuitive to us because we are familiar with things that look like non-local interactions to us. Well, entanglement _is_ intuitive in that sense, which is one of the reasons why seeing entanglement as linked with non-local collapse is so popular. > We are still having a lot of trouble making sense of quantum mechanics, therefore it seems unlikely that non-locality is at the core of quantum mechanics, because if it was and would explain everything, than it would not be so difficult to grasp quantum mechanics because we have an intuition for non-local behavior. I don't really buy this, since, quantum mechanics is intuitive and simple if we accept non-local collapse and wavefunction primacy, i.e., if you actually accept the five postulates on face value, it is not difficult to accept quantum mechanics. As a physicist myself, I don't feel bewildered or confused by quantum mechanics. I have quite a strong intuition for it, in fact.
- danbruc 3y ago
  They don't need to be because they describe totally different phenomena. In which way are they describing different phenomena? They both describe the evolution of the wave function, the Schrödinger equation while everyone is leaving the system alone, wave function collapse at those special moments when somebody is looking at the system, performing one of those mysterious measurements. Without explaining more precisely when I should use unitary evolution and when I should collapse the wave function, the Schrödinger equation together with wave function collapse are at the very least an incomplete and maybe even an inconsistent theory.
  - bowsamic 3y ago
    Again, just take a look at the postulates: Schrödinger equation describes the unitary time evolution of the system under a given Hamiltonian, wavefunction collapse describes the outcome of the non-unitary measurement process. > Without explaining more precisely when I should use unitary evolution and when I should collapse the wave function, the Schrödinger equation together with wave function collapse are at the very least an incomplete and maybe even an inconsistent theory. I don't think that QM postulates are incomplete, you just take the set of things that constitute a measurement as a premise. Let's put it this way, we have never designed an experiment where this has been an issue. So long as we define which part is the measurement beforehand, QM always predicts the results we measure. Usually it will be a photodiode or something of the sort. If QM were incomplete or inconsistent, surely we would be able to find contradictory experimental results? To summarise, the 5 basic postulates of quantum mechanics, which contains unitary evolution and non-unity measurement collapse, form a microscopic theory which no experiment has ever been able to contradict.
    - danbruc 3y ago
      Again, just take a look at the postulates: Schrödinger equation describes the unitary time evolution of the system under a given Hamiltonian, wavefunction collapse describes the outcome of the non-unitary measurement process. The outcome distribution of a measurement is described by the Born rule, the collapse postulate on the other hand tells us that the wave function will change to the actually measured state. Related but not the same. For the state |0> + |1> (unnormalized) the Born rule tells us that a measurement will yield |0> or |1> with 50 % probability each. The collapse postulate tells us that the state will change from |0> + |1> to either |0> or |1> depending on the measurement outcome. This change is non-unitary and therefore incompatible with the Schrödinger equation which tells us that quantum systems evolve unitarily. If you want, consider the combined quantum system of the system under investigation and the measurement device, why should that system not evolve unitarily?

bowsamic 3y ago

> The Schrödinger equation and wave function collapse are not compatible. They don't need to be because they describe totally different phenomena. > Maybe they could be integrated in some theory, They already are integrated into the theory of quantum mechanics. Take a look at the postulates of quantum mechanics again, one of the postulates is unitary evolution through time, another is non-unitary collapse with measurement. All the experimental results of quantum mechanics are compatible with those postulates. > Quantum mechanics in general and entanglement in particular are arguably hard to understand because they are unintuitive. If all that was going on were some non-local interactions, than entanglement would not be hard to understand because non-local interactions are intuitive to us because we are familiar with things that look like non-local interactions to us. Well, entanglement _is_ intuitive in that sense, which is one of the reasons why seeing entanglement as linked with non-local collapse is so popular. > We are still having a lot of trouble making sense of quantum mechanics, therefore it seems unlikely that non-locality is at the core of quantum mechanics, because if it was and would explain everything, than it would not be so difficult to grasp quantum mechanics because we have an intuition for non-local behavior. I don't really buy this, since, quantum mechanics is intuitive and simple if we accept non-local collapse and wavefunction primacy, i.e., if you actually accept the five postulates on face value, it is not difficult to accept quantum mechanics. As a physicist myself, I don't feel bewildered or confused by quantum mechanics. I have quite a strong intuition for it, in fact.

danbruc 3y ago
They don't need to be because they describe totally different phenomena. In which way are they describing different phenomena? They both describe the evolution of the wave function, the Schrödinger equation while everyone is leaving the system alone, wave function collapse at those special moments when somebody is looking at the system, performing one of those mysterious measurements. Without explaining more precisely when I should use unitary evolution and when I should collapse the wave function, the Schrödinger equation together with wave function collapse are at the very least an incomplete and maybe even an inconsistent theory.
- bowsamic 3y ago
  Again, just take a look at the postulates: Schrödinger equation describes the unitary time evolution of the system under a given Hamiltonian, wavefunction collapse describes the outcome of the non-unitary measurement process. > Without explaining more precisely when I should use unitary evolution and when I should collapse the wave function, the Schrödinger equation together with wave function collapse are at the very least an incomplete and maybe even an inconsistent theory. I don't think that QM postulates are incomplete, you just take the set of things that constitute a measurement as a premise. Let's put it this way, we have never designed an experiment where this has been an issue. So long as we define which part is the measurement beforehand, QM always predicts the results we measure. Usually it will be a photodiode or something of the sort. If QM were incomplete or inconsistent, surely we would be able to find contradictory experimental results? To summarise, the 5 basic postulates of quantum mechanics, which contains unitary evolution and non-unity measurement collapse, form a microscopic theory which no experiment has ever been able to contradict.
  - danbruc 3y ago
    Again, just take a look at the postulates: Schrödinger equation describes the unitary time evolution of the system under a given Hamiltonian, wavefunction collapse describes the outcome of the non-unitary measurement process. The outcome distribution of a measurement is described by the Born rule, the collapse postulate on the other hand tells us that the wave function will change to the actually measured state. Related but not the same. For the state |0> + |1> (unnormalized) the Born rule tells us that a measurement will yield |0> or |1> with 50 % probability each. The collapse postulate tells us that the state will change from |0> + |1> to either |0> or |1> depending on the measurement outcome. This change is non-unitary and therefore incompatible with the Schrödinger equation which tells us that quantum systems evolve unitarily. If you want, consider the combined quantum system of the system under investigation and the measurement device, why should that system not evolve unitarily?