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Response to Thor_MN (Reply #19)

Fri Mar 8, 2013, 10:53 PM

20. Except it's not. The state of each particle is undefined until the state of one has a consequence.

And that consequence, red or blue, is entirely random, not because we can't see some hidden state, but because that state simply does not exist until the state is determined. When one particle or the other is forced to declare a state, and the other takes on the opposite state, these forced declarations are entirely random in the same way that the disintegration of the nucleus of a radioactive element is random, or more basically, how the behavior of photons or electrons in a a single and double slit experiment is inexplicable using classical mechanics.

If you are a photon, electron, or some other elementary particle you are neither heads or tails until somebody asks. When they do ask you take a coin out of your pocket, flip it fairly, and take on the state of whatever the coin shows, heads or tails. Meanwhile, your partner, who could be halfway across the galaxy, instantaneously takes on the other state. Since this determined state is entirely random from the perspective of everyone, no information can be transmitted by this means.

Wikipedia's got this on the single/ double slit experiment and the same sort of explanation applies to quantum entanglement:

Časlav Brukner and Anton Zeilinger have succinctly expressed this limitation as follows:

The observer can decide whether or not to put detectors into the interfering path. That way, by deciding whether or not to determine the path through the two-slit experiment, s/he can decide which property can become reality. If s/he chooses not to put the detectors there, then the interference pattern will become reality; if s/he does put the detectors there, then the beam path will become reality. Yet, most importantly, the observer has no influence on the specific element of the world that becomes reality. Specifically, if s/he chooses to determine the path, then s/he has no influence whatsoever over which of the two paths, the left one or the right one, nature will tell h/er/im is the one in which the particle is found. Likewise, if s/he chooses to observe the interference pattern, then s/he has no influence whatsoever over where in the observation plane he/she will observe a specific particle. Both outcomes are completely random.


Once you've played around a bit with the particle/wave nature of electrons and photons, the weirdness of quantum mechanics isn't any more explicable, but you do realize quantum mechanics is weird and unrelated to everyday experience.

I can spend hours playing with laser pointers. If you shine a laser through something like a window screen or a kitchen strainer onto a white wall you get a pattern like this:



You think you can explain it, but then if you move the screen or the laser, it's because the shadows and reflections you thought you were seeing move the wrong way.

This sort of quantum mechanics is real in a practical sense, engineers and scientists have to deal with it in the chips and hard drives of the computers we are using, but nothing is going to make it not weird, because weird quantum things simply don't happen on the scale of our ordinary lives. We see the cats without a grin, but not the grins without a cat.

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The Straight Story Mar 2013 OP
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Thor_MN Mar 2013 #19
LineLineLineLineReply Except it's not. The state of each particle is undefined until the state of one has a consequence.
hunter Mar 2013 #20
Thor_MN Mar 2013 #25
hunter Mar 2013 #29
Thor_MN Mar 2013 #33
Jamastiene Mar 2013 #18
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