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Quantum Information Can be Negative

Posted by timothy on Mon Aug 08, 2005 05:52 PM
from the you-are-now-dumber dept.
Math Science
nerdlygirl writes "In a development that would probably even puzzle Claude Shannon, information can be negative -- at least when the information is quantum. The discovery, by Horodecki, Oppenheim, and Winter, appears in the current edition of the leading journal Nature. If I tell you negative information, you'll know less. Apparently, researchers hope to use this to gain deeper insights into phenomena such as quantum teleportation and computation, as well as the very structure of the quantum world. More details can be found here and here A popular account of the article can be found on Oppenheim's homepage, and a free version of the article can be found in the arxiv for those of us without subscriptions to Nature."
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  • This is not news (Score:3, Funny)

    by denissmith (31123) * on Monday August 08 2005, @05:54PM (#13274292)
    Karl Rove has known this for years.
    • FTFA: "It sometimes seems that we become more ignorant after talking to certain individuals. Perhaps they are saying things which are confusing or untrue. Well, after getting negative information, you know less. But not in the same sense as someone who tells you lies are tries to bamboozle you. Remember, that we don't worry about the quality of information (whether it is true or false for example). We just concern ourselves with how much there is. So, if we know less after receiving negative information, th
    • Well, you hit the gist of where pretty much everyone was going. Good example.

      I think another example would be religions.

      Or the classic Billy Madison line "we are all now stupider for having listened to that" (not sure if I phrased that exactly but it's very close to that).

      But you can look at pretty much anything in society and see this being used all the time. Look at how many people think things like Universal Health Care is bad, Schools need local control, taxes are always bad, paying off national debt
      • 1. "If I tell you negative information, you'll know less."
        2. "researchers hope to use this to gain deeper insights"

        Hmmm..... I always knew quantum physics was full of contradictions, but putting those two lines together really did make me laugh. :)

  • nope (Score:3, Funny)

    by cain (14472) on Monday August 08 2005, @05:54PM (#13274293)
    No it can't.

    • Yes it can (Score:3, Informative)

      by Anonymous Coward
      This article is not bogus.

      The concept of a "quantum eraser" is not a new one. Consider the classic double-slit experiment, where electrons are shot at a double slit and form an interference pattern on a screen which corresponds to the probability distribution of the particle's position. If you were to place detectors so that you knew which slit the particle went through, the interference pattern would disappear-- that is, there would be no uncertainty in the position (because obviously, you know which slit

        • Re:Yes it can (Score:3, Informative)

          by Anonymous Coward
          > The double slit experiment involves photons, not electrons.

          1) The experiment works with photons or electrons. The latter is more related to the experiment's most recent significance (re: the implications for quantum mechanics).

          > The paradox can be very simply explained to the lay person.

          2) Your ability to be trusted as an authority died per point 1), and the carcass is beaten by your subsequent ramblings.

          > It turned out that if one tested for particles, one got results
          > consistent with particl
  • I've been studying negative information for years. I consider myself somewhat of an expert on the subject, actually.

    Initially, I believed that negative information was an abstract math concept, but after a significant amount of additional study I've determined rather conclusively that it exists in our frame of reference and that the effects are actually easy to detect. The trick is to *locate* some of this negative information. Fortunately, I've managed to work that out as well -- I'm not publishing for a few months yet, but I figure I'm far enough along to spill some of the beans:

    Experiencing negative inforamtion is all about occupying a point in space and time which intersects with the negative information stream. This was initially tricky, but through months of tireless research I've worked out the optimal conditions: I find that your best chance of encountering it is roughly around 1 AM when you're at the bar with your friends after a long night of drinking and one of them says something along the lines of, "Awright! Time for some shots!"

    Bang! Negative information. What happened after that? How did I get home? All lost in the quantum flow, never to be accurately described by anyone involved (except, occasionally and for reasons I still haven't managed to factor into my equations, the bouncer and the police). I assume the headaches and liver damage are just a nominal side effect.

    • The Fine Article doesn't mention one exciting development in the field of information theory, related to negative information, which may one day tie it to Vacuum Energy [ldolphin.org] or Zero Point physics [ucla.edu] in a grand unified theory that, once we come to understand it, could form the basis of a star drive to power star ships. [daviddarling.info]

      It seems that virtual particles of antimatter and exotic particles of normal matter that spontaneously emerge from the void, and then disappear without interacting with anything. [1] The theoretical potential of tapping this particle flux has brought vacuum energy to the fore of research by the NSA into Quantum Information Theory.

      Experiments conducted by the NSA and the DOE on large data samples gathered in large bureaucracies (both public and private) indicate that Microsoft Word Documents are effective containers for Negative Information, which hitherto had been considered a transient phenomenon, almost impossible to store given our current understanding of physics. The phenomenon of massive amounts of stored negative informisinformation, as it turns out, makes the typical corporate or government intranet much more resiliant to cyber terrorist attack than previously predicted -- nearly as resiliant as the typical government organization to a FOIA request today, for comparison.

      It is expected that once we understand the characteristics of MS Word Documents which allow them to efficiently store negative information in a stable form, Quantum Physicists and Information Theorists should be able to get together, perhaps over a nice hot cup of tea, and stitch the two branches together, getting us one step closer to faster than light travel, finally bringing the stars within reach -- except it won't really be FTL, it will be something that we don't presently understand. [2]

      Only the humor-impaired need read this bootnote.
      [1]Yes, I see the grammar error. I've intentionally borrowed a pattern, common in conspiracy theory writing, of constructing a complex sentence, perhaps full of objects, perhaps full of verbs, perhaps full of nouns, on the theory that it might amuse, whereas it normally serves to confuse, as sometimes subjects or verbs may go missing. Oops I did it again! Or did I?
      [2]Yes, I realize I mention antimatter only in the title, and not in the text.
      [3]Yes, I realize there are 3 bootnotes, not a single bootnote as referenced above.
      [4]Yes, I realize that only 2 of the bootnotes are indicated by reference numbers in the text. (Absurd bootnotes are also common in conspiracy theorist writings.)

  • I already knew this (Score:3, Funny)

    by 77Punker (673758) <spencr04@@@highpoint...edu> on Monday August 08 2005, @05:54PM (#13274295)
    If I tell you negative information, you'll know less. Sounds like what happened in that mind numbing English class I had to take last semester.

  • when you asked me to take the trash out (Score:4, Funny)

    by mrsbrisby (60242) on Monday August 08 2005, @05:54PM (#13274296) Homepage
    it was negative information so I forgot how to get my socks in the dirty clothes.

  • True (Score:5, Funny)

    by M.C. Hampster (541262) <M.C.TheHampster@gm a i l .com> on Monday August 08 2005, @05:54PM (#13274297) Journal
    After trying to read those articles, I do feel like I know less.
  • Considering some of the posters here, I wouldn't be surprised if that were discovered.

  • When I was in high school (Score:5, Funny)

    by multiplexo (27356) * on Monday August 08 2005, @05:55PM (#13274311) Journal
    a friend and I used to joke that there were people who gave off destructive mental interference waves. Sitting next to these people would result in a decrease in brain function because their brainwaves were 180 degrees out of phase than the brainwaves of normal people, thus cancelling them out and creating a thought-free zone.

    Of course negative information is cool, but it would be even cooler if you could combine negative information and positive information to produce a huge explosion.

  • If I tell you negative information, you'll know less.

    So, if two people tell me negative information, I'll know more?

  • If I tell you negative information, you'll know less.

    I experience this almost everytime I speak to my boss.

  • Affects black holes! (Score:5, Interesting)

    by sconeu (64226) on Monday August 08 2005, @05:56PM (#13274320) Homepage Journal

    Since a black hole's entropy is directly proportional to it's information content, this, if true, would have an effect on black holes.

    If I recall correctly (and I may not -- my physics isn't what it used to be), the amount of information contained by a black hole is directly proportional to its surface area -- specifically, I believe that the total number of bits contained is equal to 1/4 of its surface area as measured in Planck units.

    Now, if information can be negative, that would provide another method of shrinking a black hole, in addition to Hawking radiation.

  • Bad Analogy (Score:5, Insightful)

    by ravenspear (756059) on Monday August 08 2005, @06:00PM (#13274359)
    If I tell you negative information, you'll know less.

    I don't think that really works. You can't make someone know less by just telling them something, unless by doing so you somehow alter their brain chemistry to store less information or remove information already stored. I suspect this might be closer to the quantum idea.

    Suppose you have two pieces of quantum information, one positive and one negative. The negative piece could negate the positive one which would result in 0 total pieces of information instead of 2.

    However, the idea of this negative information is still kind of abstract and not that easy to understand. The quantum nature of this is key I think. It doesn't look like it extends that well to our concept of information (which would be the kind stored by the brain), at least not yet.
      • I think this may be close, but inaccurate. It doesn't reduce the psychic's information (unless he didn't know he was a psychic), but rather the information in the system.
        Let's say there exists a person, Alfred, who is a psychic. Nobody knows he is a psychic (except perhaps himself), but he is. He is approached by Bill, who has Â$55 in his wallet. Alfred senses the $55. There is now information in the system that "Alfred is a psychic" because if he tells Bill about the $55 without Bill showing them to h

  • Old philosophy, revisited... (Score:3, Funny)

    by gmuslera (3436) on Monday August 08 2005, @06:04PM (#13274387) Homepage Journal
    "One thing only I know, and that is that I know less than nothing" - Socratum
  • All this time I wondered how so many people could be so stupid as to believe the mountains of bullshit pushed by the creationist movement, and this explains it!

    As information regarding the field of biology -- specifically in the study of evolution -- increases, a balance must be made. As a result, the increase of information in biology causes a reaction of an equal increase of negative information with respect to the creationist movement. The more biologists figure out and the more knowledgable experts become, the dumber and more gullible the general populace must become to balance the information flow out.
  • He wrote, "The scholar learns something every day, the man of tao unlearns something every day, until he gets back to non-doing."

  • Math (Score:3, Insightful)

    by Mark of THE CITY (97325) on Monday August 08 2005, @06:20PM (#13274522) Homepage
    Would it be accurate to analogize this to antimatter, in the sense that the latter was found mathematically first, and observed later (and maybe not yet)?

  • I think Feynman thought of this first (Score:5, Informative)

    by mbone (558574) on Monday August 08 2005, @06:23PM (#13274544)
    I distinctly remember a lecture by Feynman at Caltech in the early 1980's where he talked about negative information (probability). I am sure I still have notes for it somewhere. Of course, you can never see negative information; any actual measurement has to have positive probility. But it can give quantum interference effects in measured quantities.

    Feynman presented it as just a different way of having quantum interference, from negative probability instead of complex amplitudes.
      • Nope. Even though Feynman had negative probabilities, the information was still positive. He used negative AND positive probabilities, and the net effect would still lead to positive information (if you added everything up). The authors say that information is due to entanglement. Feynman was only talking about single particles going through slits, so there could be no entanglement in his example (entanglement requires two particles).

        Two things. First, can we observe negative information? Sounds to me li

        • Re:I think Feynman thought of this first (Score:3, Informative)

          by Anonymous Coward
          Two things. First, can we observe negative information? Sounds to me like we still just observe nonnegative information. That hasn't changed. Appears to me that negative information is virtual which is quite in line with Feynman's points.

          What do you mean by observe? If you mean, what is the information of the things we see, then what you say sounds right. Because classical information is positive always. If you mean, can we tell that the information is negative, then it seems we can -- the authors show

  • Escort Web Pages (Score:3, Interesting)

    by pyrrhonist (701154) on Monday August 08 2005, @06:37PM (#13274641)
    From the author's homepage:
    This web page has about 2500 English words, so it is
    convoying more information (although I can't speak to the quality of that information).
    But English is a very silly language...

    That's not really how you use that word. His spell checker must have provided negative information.

  • It's your stock of entangled particles (Score:5, Informative)

    by iabervon (1971) on Monday August 08 2005, @07:02PM (#13274823) Homepage Journal
    The trick is that you can use quantum entanglement to have excess unspecified knowledge, which can be converted into specific knowledge. It's like being on a quiz show where you are given a certain number of times you can look up an answer. These bonuses have to count in your total knowledge (I know 100 facts, plus I can look up things twice). If someone tells you something, you get positive information. If you look something up, you get zero information (you trade a bonus lookup for a fact). If you look something up, and you already knew the answer, you get negative information.

    Now think about it as if someone else controlled the book. They can tell you things over the phone, and they can cause answers to pop out of the book. If they waste the book on something you actually already knew, your total information goes down, so the information in the transaction is negative.

  • I think I have this figured out... (Score:3, Informative)

    by lawpoop (604919) on Monday August 08 2005, @09:06PM (#13275492) Homepage Journal
    IANA Physicist, and I'm terrible at math. But I think I have this figured out.

    In order to learn something, you have to make a measurement. Of course, in the quantum world, measuring a system will change it, so you are giving up what you know by measuring. It seems that in negative information situations, you are giving up your certainty in order to measure something, but your aren't learning anything in return. So your net 'gain' of information is negative.

  • But it doesn't work at absolutes (Score:4, Funny)

    by gearmonger (672422) on Tuesday August 09 2005, @12:51AM (#13276367)
    Utter ignorance is the total lack of information, or the complete absence of knowledge. We all know that nowledge is power, and power is force over time. Time is money, so knowledge is force over money. Ergo, someone who is ignorant has no force over money, which is certainly ironic given that the Nature article is entitled "Quantum Information: Putting certainty in the bank". Yes, poor people are easy to make fun of even in quantum states (which were formally known as blue states until the manic depressives complained about trademark infringement).
    • The article calls this a measurement of the quality of the information, which they say has no bearing on the quantity. The thing about quantum information is that due to the fact that the amount of information contained can lessen by measuring the information, it is actually possible to know more about a quantum object than actually describes it. Think of it more like looking at a comet in space. You can learn more about it by hitting it with explosives and measuring the spectral result, but in doing so you are actually destroying bits of the comet. So eventually, you can know all about an object that doesn't actually exist. Of course, unlike comets, quantum objects can be both there and not there at the same time; the time factor of it being destroyed after it has been measured is effectively removed.

    • At least one (Score:4, Informative)

      by Quadraginta (902985) on Monday August 08 2005, @06:44PM (#13274690)
      Geez, don't be so cynical. After I got my PhD from Berkeley, with a dissertation in quantum mechanics, I taught the stuff to graduate students for five years or so. I've published QM papers in PRA and all that, too. So, yeah, I know what they mean. I'm perfectly qualified to review their Nature paper, if it comes to that, and I doubt I'm the only one like this reading /.

      I have to say I'm not especially impressed by the work, however. The frisson of defining information as negative emerges ultimately from a semi-deliberate muddling of the distinction between the definition of information in the quantum computing context and information as we use the word in daily life. This is not hard useful scientific discovery so much as the scientific equivalent of making an outrageous pun.

      But then I feel similarly about most of what's published in the Bell's Inequality, EPR paradox, quantum tele-whatever field. Getting cynical myself, maybe I am....bah, humbug...grumble...

      • This is pretty much my reaction, and I have a similar background.

        It has been known for a long time that quantum information can be negative. But no one has known how to interpret it. These guys are giving one possible interpretation out of the infinitely many possible ones. It is a good interpretation as it has some operational significance, but I've always found interpretive papers to be less than satisfying as science (which is why I've never published one, despite having some interesting ones.)

        They ar
        • I am also a researcher near to this field, and actually heard it presented at a conference a few months back. The reaction of the people I know (who actively do research in this area, more so than myself), was one of extreme excitement. I think perhaps you don't understand the result.

          Quantum information is not a question of interpretation -- it is well known what it is, in terms of communication theory. What these guys did, is prove how much communication was required to send information, if the receiv

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