Quantum Information Can be Negative 445
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."
Bad Analogy (Score:5, Insightful)
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.
Re:Ouch! (Score:0, Insightful)
Oh, man! I wonder how many /.-ers will get this :) (Score:2, Insightful)
So first off you need an understanding of QM (it's statistical information, so screw the Kopenhagen interpretation
Shit, I'm getting to my third year of applied physics, and I'm just grokking the basics of QM, let alone the concept of 'information' (let alone positive or negative) in QM
Math (Score:3, Insightful)
Re:I wonder... (Score:5, Insightful)
Re:This explains the Creationist/ID movement (Score:2, Insightful)
(I also appologize for my apparent over-use of conjunctions today :P)
Re:Yes it can (Score:2, Insightful)
You clearly know nothing about quantum mechanics. The slit is not a detector because, put simply, it does not detect anything. The whole point of the double slit experiment was to show that if there are two slits, there is some uncertainty as to which one the particle went through. This is due to the interference of the wavefunctions.
Before you accuse others of BSing, learn some quantum physics. It's quite interesting.
Re:Best place for negative information (Score:3, Insightful)
PowerPoint & Storing Negative Information (Score:3, Insightful)
Re:At least one (Score:2, Insightful)
That's exactly his point, too. The OP appreciates work that is actually contributing new knowledge. His point was that the article in question is just rambling without making any significant contribution to the body of knowledge in the field.
While I'm not in quantum physics or computing, I am quite familiar with the academic problem the OP is grumbling about: There are too many papers published with too few actual discoveries. The problem is that padding one's CV is more important to certain aspects of one's professional reputation than making significant discoveries. This leads to lots of papers being written with long references sections that ramble on basically rehashing old work and making "interesting observations" about what things "might" mean. The subtext of "might" of course being that the author cannot say anything for sure, but wants to do a lot of namedropping in the process.
Re:Yes it can (Score:2, Insightful)
The claim made is that if you pu a detector on on of the slits, to record which way the photon goes, it changes the results. The implied claim is that some observer effect collapses the uncertainty. You don't get to go around arbitrarily designating some objects observers and others not just to make your theory consistant! The phenomena is quite interesting, but let's get a theory that makes sense without this "observer" magic.
Negative quantum information (Score:1, Insightful)
Re:At least one (Score:2, Insightful)
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.
Kind of like what happened with relativity/relativism ("everything is relative, Einstein even proved it").
Re:At least one (Score:3, Insightful)
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 are also almost certainly catering to popular misunderstanding in the same way the quantum "teleportation" people do. Use of common terms in a way that you know is going to be misinterpreted is bad science, does the public a disservice, and violates the scientist's obligation to spread truth and understanding rather than obscurity and confusion.