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posted by LaminatorX on Saturday August 09 2014, @08:04PM   Printer-friendly
from the flock-together dept.

Physicists at Chapman University have discovered a new quantum paradox, the "quantum pigeonhole paradox". In their somewhat cringe-inducing press release, they write:

The classical pigeonhole principle states: "If you put three pigeons in two pigeonholes at least two of the pigeons end up in the same hole." This is an obvious yet fundamental principle of nature as it captures the very essence of counting. Yet the Chapman team showed that it was false in quantum mechanics: "You can put an infinite number of pigeons in two boxes, and no two pigeons will be in the same box," says Tollaksen.

Most of the press release seems to be going on about the two-state vector formalism, for which the new result might have consequences. The essence of the trick that allows the paradox is cooking up a weak quantum measurement that effectively asks whether a pair of particles are in the same box without asking in which box they are. From the original paper,:

Finally, and most importantly, we note that the global measurement is a measurement of an operator with entangled eigenstates and it requires either to put the particles in interaction or consume some entanglement resources to perform it. The quantum pigeonhole effect is thus an example of a new aspect of entanglement: entanglement in the measurement is needed to reveal correlations existing in a direct product state.

The paper even describes an experimental setup that implements the described measurements.

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  • (Score: 2) by frojack on Saturday August 09 2014, @08:43PM

    by frojack (1554) on Saturday August 09 2014, @08:43PM (#79440) Journal

    "You can put an infinite number of pigeons in two boxes, and no two pigeons will be in the same box," >/blockquote>

    Sort of like ACs.
    All in the same pigeon hole, but none of them accept responsibility for the guano.

    (except gewg who oddly signs his AC posts)?.

    --
    No, you are mistaken. I've always had this sig.
    • (Score: 0) by Anonymous Coward on Saturday August 09 2014, @09:08PM

      by Anonymous Coward on Saturday August 09 2014, @09:08PM (#79449)

      I accept responsibility

    • (Score: 2) by cafebabe on Saturday August 09 2014, @09:14PM

      by cafebabe (894) on Saturday August 09 2014, @09:14PM (#79452) Journal

      (except gewg who oddly signs his AC posts)?.

      Anyone can sign an anonymous post as gewg_ and it may be shared pseudonym by consent.

      --
      1702845791×2
      • (Score: 2) by frojack on Saturday August 09 2014, @09:43PM

        by frojack (1554) on Saturday August 09 2014, @09:43PM (#79461) Journal

        True. Guano, Every Where, Guano.

        --
        No, you are mistaken. I've always had this sig.
      • (Score: 0) by Anonymous Coward on Sunday August 10 2014, @01:26AM

        by Anonymous Coward on Sunday August 10 2014, @01:26AM (#79508)

        That's bullshit. No one impersonates me.

        -- gewg

        • (Score: 0) by Anonymous Coward on Sunday August 10 2014, @02:33AM

          by Anonymous Coward on Sunday August 10 2014, @02:33AM (#79527)

          Right.
          -- gewg

          • (Score: 1, Funny) by Anonymous Coward on Sunday August 10 2014, @02:44AM

            by Anonymous Coward on Sunday August 10 2014, @02:44AM (#79529)

            I see what you did there.

            --gewg

            • (Score: 2) by rts008 on Sunday August 10 2014, @02:59AM

              by rts008 (3001) on Sunday August 10 2014, @02:59AM (#79532)

              You are all imposters!

              I'm the REAL me!

              --gewg

        • (Score: 0) by Anonymous Coward on Sunday August 10 2014, @05:22PM

          by Anonymous Coward on Sunday August 10 2014, @05:22PM (#79691)

          If you're going to impersonate me, at least get the signature right.

          -- gewg_

          • (Score: 0) by Anonymous Coward on Wednesday August 13 2014, @04:56PM

            by Anonymous Coward on Wednesday August 13 2014, @04:56PM (#80868)

            Thank you for saving me the trouble.

            -- gewg_

  • (Score: 3, Interesting) by khallow on Saturday August 09 2014, @08:43PM

    by khallow (3766) Subscriber Badge on Saturday August 09 2014, @08:43PM (#79441) Journal

    that effectively asks whether a pair of particles are in the same box

    How about a "weak quantum measurement" that "asks" whether for three particles, a pair of them (there are three possible pairs here and they all have to be observed simultaneously) are in the same box? You know, the actual sort of measurement that would need to be made in order to demonstrate the assertion that there is a quantum pigeonhole paradox.

    • (Score: 2) by wonkey_monkey on Saturday August 09 2014, @09:48PM

      by wonkey_monkey (279) on Saturday August 09 2014, @09:48PM (#79466) Homepage

      From the paper:

      We find instances when three quantum particles are put in two boxes, yet no two particles are in the same box.

      Consider three particles and two boxes

      Consider again three particles and two boxes.

      The overall state of the three particles is therefore [...] We want however to show that there are instances in which we can guarantee that no two particles are together

      In other words [...] we have three particles in two boxes, yet no two particles can be found in the same box - our quantum pigeonhole principle.

      --
      systemd is Roko's Basilisk
      • (Score: 2) by khallow on Saturday August 09 2014, @10:05PM

        by khallow (3766) Subscriber Badge on Saturday August 09 2014, @10:05PM (#79470) Journal

        In other words, they aren't doing the measurement in question.

  • (Score: 0) by Anonymous Coward on Saturday August 09 2014, @10:16PM

    by Anonymous Coward on Saturday August 09 2014, @10:16PM (#79473)

    So, if you want to transport 20,000 pigeons in a 10,000-pigeon container, you have to keep half of them quantum-entangled at all times?

    • (Score: 2) by cafebabe on Saturday August 09 2014, @11:21PM

      by cafebabe (894) on Saturday August 09 2014, @11:21PM (#79490) Journal

      If you have 20,000 pigeons and 10,000 pigeonholes, you can store 9,998 pigeons classically and store the remaining 10,002 pigeons in two quantum pigeonholes. Or you can store all of the pigeons in two quantum pigeonholes and leave 9,998 pigeonholes unused.

      --
      1702845791×2
      • (Score: 2) by HiThere on Sunday August 10 2014, @07:34PM

        by HiThere (866) Subscriber Badge on Sunday August 10 2014, @07:34PM (#79737) Journal

        No, you just need to keep 10,000 pigeons in flight all the time.

        --
        Javascript is what you use to allow unknown third parties to run software you have no idea about on your computer.
      • (Score: 0) by Anonymous Coward on Monday August 11 2014, @03:40AM

        by Anonymous Coward on Monday August 11 2014, @03:40AM (#79892)

        We can not count real number because of between any two numbers there is infinity of numbers.
        Quantum Pigeonhole principle violates some kind of conservation principle, may be of counting!?

  • (Score: 1) by citizenr on Saturday August 09 2014, @10:49PM

    by citizenr (2737) on Saturday August 09 2014, @10:49PM (#79484)

    More evidence pointing to simulation optimizations.

  • (Score: 4, Insightful) by maxwell demon on Sunday August 10 2014, @05:22AM

    by maxwell demon (1608) on Sunday August 10 2014, @05:22AM (#79564) Journal

    I fundamentally mistrust the interpretation of every experiment which consists of measuring a weak value followed by postselection. I suspect that it all boils down to the quantum analogue to statistical selective bias.

    Indeed, for the quantum Cheshire cat experiment we discussed recently [soylentnews.org] there was an article on arXiv [arxiv.org] this week where the author explains that the experiment in question can be explained by classical selective bias.

    --
    The Tao of math: The numbers you can count are not the real numbers.
  • (Score: 2) by Rivenaleem on Monday August 11 2014, @01:22PM

    by Rivenaleem (3400) on Monday August 11 2014, @01:22PM (#80037)

    It also explains the principle by which Sean Bean is pigeon-holed in TV and Movies. He's both alive and dead until the show is observed.

  • (Score: 0) by Anonymous Coward on Monday August 11 2014, @07:09PM

    by Anonymous Coward on Monday August 11 2014, @07:09PM (#80168)

    i suppose these language tricks would be quite useful if one found oneself in a dark cave having a battle of riddles with gollum.