Hardy's Paradox - Which Way Information

In summary, the paper by Prof. Hardy and his team provides evidence that it is possible to distinguish between the two scenarios of wavefunction collapse - instantaneous and time-finite. This has profound implications for the theory of quantum mechanics, as it suggests that some aspects of reality may not be real.
  • #1
StevieTNZ
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I have three quick questions regarding the experimental set-up attached, in relation to Hardy’s Paradox.

What possible detections are available, according to Quantum Mechanics, and do those detections indicate, for the electron and the positron, which path they took? I’m guessing not as at the beam splitters, there is ½ probability of being reflected and ½ probability of being transmitted. In accord with QM, are they are in a superposition, after the beam splitter, as being both reflected and transmitted?

Because the particles in question are in a superposition of being in both paths (e+ in a superposition of paths u+ and w+/u+, and e- in a superposition of paths v- and w-/u-), they’re strictly not ‘real’ (this is where the realism refutation comes about, in standard QM), thus the particles cannot interact and annihilate?
 

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  • #2
that stuff can happen only if the wavefunction collapse is instantaneous.
 
Last edited:
  • #3
work in progress
http://arxiv.org/abs/1303.2972
"We find that it is possible to discriminate between the scenarios of instantaneous collapse and finite-time reduction via a large number of double measurements of polarization. The quantities to be recorded would present distinct behaviors in each scenario, the deviations being small but distinguishable from pure statistical fluctuations"
 
  • #4
audioloop said:
work in progress
http://arxiv.org/abs/1303.2972
"We find that it is possible to discriminate between the scenarios of instantaneous collapse and finite-time reduction via a large number of double measurements of polarization. The quantities to be recorded would present distinct behaviors in each scenario, the deviations being small but distinguishable from pure statistical fluctuations"

First draft looks pretty nice, audioloop.
 
  • #5
It would seem from that paper that instantaneous collapse is compatible with QM - than time-finite collapse - by looking at the two tables they provide results in.
 
  • #6
Indeed. has profund implications.
 
  • #7

1. What is Hardy's Paradox - Which Way Information?

Hardy's Paradox - Which Way Information is a thought experiment proposed by physicist Lucien Hardy in 1992. It explores the concept of information being obtained from a system without physically interacting with it.

2. What is the paradox in Hardy's Paradox - Which Way Information?

The paradox lies in the fact that according to quantum mechanics, the mere act of observing a system can alter its state. Therefore, if information can be obtained without physically interacting with the system, it would seem to contradict the principles of quantum mechanics.

3. How does Hardy's Paradox - Which Way Information work?

The thought experiment involves two particles, A and B, in an entangled state. Particle A is sent through two detectors, while particle B is sent through only one. The detectors are set up in such a way that if particle A is detected by both detectors, then particle B must have passed through a specific path. However, if particle A is detected by only one detector, then particle B's path is unknown. This leads to the paradox of obtaining information about particle B's path without physically interacting with it.

4. What are the implications of Hardy's Paradox - Which Way Information?

The paradox challenges our understanding of the relationship between observation and reality in quantum mechanics. It suggests that information can be obtained about a system without physically interacting with it, which conflicts with the principles of quantum mechanics. This has implications for our understanding of causality and the role of the observer in quantum systems.

5. Has Hardy's Paradox - Which Way Information been resolved?

There is ongoing debate and research surrounding the paradox, with various proposed resolutions. Some suggest that the paradox can be explained by quantum entanglement, while others propose modifications to the laws of quantum mechanics. However, there is no widely accepted resolution to the paradox at this time.

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