maline
- 436
- 69
My "weird result" is the standard one that I assume stevendaryl intends: A and B both have 1/2 in all entries, E=[(0,1);(1,0)], F=[(3/4,1/4);(1/4,3/4)].
This is generated by transmitting pairs of entangled electrons with total spin 0, but as required, the weirdness is in the result itself.
I consider this weird for two reasons:
1. I expect a model of reality to be expressible in terms of variables- of any form-(field strength, wavefunction amplitude, particle momentum, or anything else) that are defined at each point in spacetime and that evolve, at each point, according to incoming information from the past lightcone, plus possibly some completely random changes, where the distribution depends only on such incoming information. Bell proved that no such model can predict the above outcome. This forces me to try to define & adopt some other concept of reality. As of yet I have not done so, so all I can say is "the results are weird".
2. If we assume that measurement of a quantum variable with more than one possible value is fundamentally nondeterministic (as most people seem to conclude), meaning that before the measurement, the universe does not contain the information of what the result will be, then I see the above result as showing a superluminal effect, as follows:
Let us work in a reference frame such that Alice's measurements occur before Bob's. Consider a pair of measurements that occur immediately after a change in pointer direction, such that Alice's choice of setting & Bob's measurement are spacelike separated. An observer who sees Alice's red light flash, and sees her pointer setting, can say with confidence, "if Bob has this setting, then his blue light is about to flash". If Bob does in fact have the same setting, as noted afterward by Yvonne, then his blue light will indeed flash. But before the measurement, the information (that the blue light will flash) does not exist in Bob's region! If information about a result exists in one part of the universe & not in another part, and afterward this "prediction" comes true in the second region, I don't see how to escape the conclusion that the information traveled, in this case superluminally. (this point is also stevendaryl's, from the earlier thread). Superluminal effects are weird because time order is not defined at spacelike separation. The fact that this effect cannot be used to transmit information only makes it weirder: "But I was thinking of a plan to dye my whiskers green/ And always use so large a fan that they could not be seen".
This is generated by transmitting pairs of entangled electrons with total spin 0, but as required, the weirdness is in the result itself.
I consider this weird for two reasons:
1. I expect a model of reality to be expressible in terms of variables- of any form-(field strength, wavefunction amplitude, particle momentum, or anything else) that are defined at each point in spacetime and that evolve, at each point, according to incoming information from the past lightcone, plus possibly some completely random changes, where the distribution depends only on such incoming information. Bell proved that no such model can predict the above outcome. This forces me to try to define & adopt some other concept of reality. As of yet I have not done so, so all I can say is "the results are weird".
2. If we assume that measurement of a quantum variable with more than one possible value is fundamentally nondeterministic (as most people seem to conclude), meaning that before the measurement, the universe does not contain the information of what the result will be, then I see the above result as showing a superluminal effect, as follows:
Let us work in a reference frame such that Alice's measurements occur before Bob's. Consider a pair of measurements that occur immediately after a change in pointer direction, such that Alice's choice of setting & Bob's measurement are spacelike separated. An observer who sees Alice's red light flash, and sees her pointer setting, can say with confidence, "if Bob has this setting, then his blue light is about to flash". If Bob does in fact have the same setting, as noted afterward by Yvonne, then his blue light will indeed flash. But before the measurement, the information (that the blue light will flash) does not exist in Bob's region! If information about a result exists in one part of the universe & not in another part, and afterward this "prediction" comes true in the second region, I don't see how to escape the conclusion that the information traveled, in this case superluminally. (this point is also stevendaryl's, from the earlier thread). Superluminal effects are weird because time order is not defined at spacelike separation. The fact that this effect cannot be used to transmit information only makes it weirder: "But I was thinking of a plan to dye my whiskers green/ And always use so large a fan that they could not be seen".