The discussion revolves around the behavior of photons in quantum mechanics, particularly focusing on their properties before and after measurement, the concept of determinism versus randomness, and the implications of polarizers on photon states. Participants explore theoretical interpretations and experimental setups related to these phenomena.
Participants express multiple competing views regarding the nature of photon measurement, determinism, and the effects of polarizers. The discussion remains unresolved, with no consensus on the implications of these concepts.
Participants highlight the complexity of quantum states and measurement, noting that definitive statements about photons 'in transit' are challenging. The discussion reflects various interpretations of quantum mechanics and the role of measurement in determining photon properties.
San K said:you can rotate but not predict the outcome?
DrChinese said:True. If the input is unknown, the output is the same but rotated, even if unknown still.
If the input is indeterminate, i.e. in a superposition of states, then after passing through the waveplate the output is also indeterminate, although in a different superposition of states.San K said:is it unknown but not indeterminate?
lugita15 said:If the input is indeterminate, i.e. in a superposition of states, then after passing through the waveplate the output is also indeterminate, although in a different superposition of states.
If it is in a superposition of polarization states to start with, then as soon as it passes through the first polarizer the wave function will collapse and it take on a state of definite polarization, either parallel to the orientation of the first polarizer or perpendicular to the orientation of the first polarizer. Then, after it passes through the second polarizer, it will have a new state of definite polarization, either parallel to the orientation of the second polarizer or perpendicular to the orientation of the second polarizer, with the probability of becoming polarized in the direction of the second polarizer being equal to the cosine squared of the difference in angle between the two polarizers.San K said:well clarified lugita, how about after passing through a first polarizer (assume it was indeterminate to start with) and then a second polarizer?
lugita15 said:If it is in a superposition of polarization states to start with, then as soon as it passes through the first polarizer the wave function will collapse and it take on a state of definite polarization, either parallel to the orientation of the first polarizer or perpendicular to the orientation of the first polarizer.
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Then, after it passes through the second polarizer, it will have a new state of definite polarization, either parallel to the orientation of the second polarizer or perpendicular to the orientation of the second polarizer, with the probability of becoming polarized in the direction of the second polarizer being equal to the cosine squared of the difference in angle between the two polarizers.
Sorry, by polarizer I didn't mean a polarized filter, which destroys photons which are polarized perpendicular, but rather a polariscope like the one discussed http://quantumtantra.com/bell2.html.mathal said:*** The problem with the logic that there are two lines of probability flowing from any polarized filter is that a polarized filter precludes this possibility.l
Thanks for that clarification. The link you provided had a neat shot of the two polarized images of a page of print seen through a calcite crystal.lugita15 said:Sorry, by polarizer I didn't mean a polarized filter, which destroys photons which are polarized perpendicular, but rather a polariscope like the one discussed http://quantumtantra.com/bell2.html.