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Buzz Bloom
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- Has the thought experiment described as the Einstein-Pedolsky-Rosen 1935 "paradox" ever been experimentally explored?
While I have have heard about it for years, I have just read a more-or-less clear description of the EPR "paradox" in David Lindley's Where Does the Weirdness Go? (1996), page 91, "The fatal blow?". Here is a summary (paraphrasing what I read) as I understand it.
A pair of particles (say A and B) is created which move at the same momentum in opposite directions. A device is set up to measure the position of A. The Heisenberg uncertainty principle requires that the the product of the uncertainty (standard deviation) in position (σx) and the uncertainty in momentum (σp) must exceed h/4π.
Assume that the standard deviation σx of 1,000,000,000 A's measurements is (for example)
It seems plausible that an experiment might be performed similar to the above which would confirm that the change in the value of σp depends on whether or not A is measured. Does anyone know if such an experiment has ever been performed?
A pair of particles (say A and B) is created which move at the same momentum in opposite directions. A device is set up to measure the position of A. The Heisenberg uncertainty principle requires that the the product of the uncertainty (standard deviation) in position (σx) and the uncertainty in momentum (σp) must exceed h/4π.
σx σp ≥ h/4π
h = 6.62607015×10−34 kg m2 / s
H = h/4π = 5.29285909×10−33 kg m2 / s
There is another device set up to measure B's momentum, some time after A's position is measured.Assume that the standard deviation σx of 1,000,000,000 A's measurements is (for example)
σx = 5.00000000×10−30 m.
Assume that if A is not measured, then the standard deviation σp of 1,000,000,000 B's measurements is (for example)σp = 5.00000000×10−30 kg m / s.
However, if A and B are measured 1,000,000,000 times, the standard deviation of B's measurements must then be the much greater valueσp ≥ 1.05457182×10−3 kg m / s.
It seems plausible that an experiment might be performed similar to the above which would confirm that the change in the value of σp depends on whether or not A is measured. Does anyone know if such an experiment has ever been performed?