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Honestly, I've never quite gotten the hang of what a 'weak' measurement is, but since these are widely used in a variety of experiments involving quantum mechanics, the idea that they don't provide any actual information about the quantum world would be pretty important.
An example of one recent experiment that uses weak measurements is the quantum pigeon hole paradox.
The idea behind weak measurements is to avoid collapsing the wave function with a direct observation. In the pigeon hole paradox experiment, this is done by seeing if a magnetic field along one of the paths causes a change that indicates an electron passed along that path. So you don't actually measure if an electron did or didn't pass, instead, you create a disturbance in the motion of any electrons that do happen to pass. Later, you measure which electrons were actually perturbed - at least this is my best reading of the thought experiment.
But using weak measurements seems to create a number of results that are very weird even by quantum mechanics' standards. The quantum cheshire cat experiment is a good example of this. There, the researchers seemed to be able to send neutrons down one path but their spins down another. The implication is that any property of a particle can be separated from the particle itself.
But both experiments relied on weak measurements. So if these turn out to represent something like classical probabilities rather than the type that exist in the quantum world, it could well invalidate some of these new 'discoveries.'
Article.
An example of one recent experiment that uses weak measurements is the quantum pigeon hole paradox.
The idea behind weak measurements is to avoid collapsing the wave function with a direct observation. In the pigeon hole paradox experiment, this is done by seeing if a magnetic field along one of the paths causes a change that indicates an electron passed along that path. So you don't actually measure if an electron did or didn't pass, instead, you create a disturbance in the motion of any electrons that do happen to pass. Later, you measure which electrons were actually perturbed - at least this is my best reading of the thought experiment.
But using weak measurements seems to create a number of results that are very weird even by quantum mechanics' standards. The quantum cheshire cat experiment is a good example of this. There, the researchers seemed to be able to send neutrons down one path but their spins down another. The implication is that any property of a particle can be separated from the particle itself.
But both experiments relied on weak measurements. So if these turn out to represent something like classical probabilities rather than the type that exist in the quantum world, it could well invalidate some of these new 'discoveries.'
Article.