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> The imprecise talk of “observer” and a “measurement” that plagues the orthodox interpretation is thus avoided because the wave function collapses spontaneousl
by systemvoltage 6y ago
> The imprecise talk of “observer” and a “measurement” that plagues the orthodox interpretation is thus avoided because the wave function collapses spontaneously.
Why? Measurement is just a photon you shoot at something. Or electron. Wikipedia is saying we cannot define what an observer is and what constitutes “measurement” - sure we do, measurement interacts with the quantum mechanical system because we need to use something - a photon or an electron or some particle to see how it interacts with the system.
- gotostatement 6y agoI'm not knowledgable of QM. But I don't think that's necessarily true, because photons/electrons are interacting with the system at all times, but the wave function doesn't collapse until we actually observe the result of one of those photons/scatters/whatever, right?
- systemvoltage 6y agoSame, not too knowledgeable but I thought this was no longer a mystery.
- gotostatement 6y agomy point is that, a photon bouncing off the system doesn't suffice as a measurement, because photons and electrons are always interacting with the system, but the measurement/wave function collapse doesn't occur until there's some other type of observation that occurs, e.g. a photon that's specifically sent and read by the experimenter
- aeternum 6y agoSuppose you fire a photon through a polarizing filter. If the photon's polarization is orthogonal to the filter, it will be blocked however if not orthogonal, the photon can pass through with some probability. Does putting the photon through the filter count as a measurement?
- systemvoltage 6y agoWouldn't checking if photon is polarized or not (using a 2nd filter) count as a measurement? I am not too versed in quantum mechanics, perhaps you can educate?
- aeternum 6y agoSuppose you have two polarized filters at 90 degrees to each other. These block out all the light so you could say that this setup is a form of measurement, since it provides knowledge that zero light is passing through. In classical mechanics, adding a 3rd filter between the two would have no effect since already no light is getting through. However with quantum putting a 3rd filter between your two original filters at 45 degrees will allow half of the photons to pass through all 3 filters. This is where things get strange and measurement is not very well defined. Are any of the 3 filters now performing a measurement? We know that half the photons will pass through but have no way of determining which will and which won't. This experiment works with polarized sunglasses btw, quantum in the palm of your hands.
- systemvoltage 6y agoThank you, that was a fascinating explanation.