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Physicists Create Quantum Link Between Photons That Don't Exist At the Same Time 364

sciencehabit writes "Physicists have long known that quantum mechanics allows for a subtle connection between quantum particles called entanglement, in which measuring one particle can instantly set the otherwise uncertain condition, or 'state,' of another particle—even if it's light years away. Now, experimenters in Israel have shown that they can entangle two photons that don't even exist at the same time. Anton Zeilinger, a physicist at the University of Vienna, says that the experiment demonstrates just how slippery the concepts of quantum mechanics are. 'It's really neat because it shows more or less that quantum events are outside our everyday notions of space and time.'"
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Physicists Create Quantum Link Between Photons That Don't Exist At the Same Time

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  • by Anonymous Coward on Thursday May 23, 2013 @12:17AM (#43800203)

    'It's really neat because it shows more or less that quantum events are outside our everyday notions of space and time.'"

    No, not really. You're simply see the macro effects of partial photons interacting, and unwilling to give up the idea of the discrete photon.

    If all you can see (and measure) is a photons promotion and demotion of electrons, you an only see the fast shift of the big circles jumping around in this picture, not the slower smaller drift that is happening.

    Give up your photon model, it's based on a faulty understanding.

  • by Laxori666 ( 748529 ) on Thursday May 23, 2013 @12:22AM (#43800235) Homepage
  • Re:Science (Score:3, Insightful)

    by Nyder ( 754090 ) on Thursday May 23, 2013 @12:38AM (#43800297) Journal


    Let's all pretend the last 80+ years of science didn't happen and we live under Newton's ideas of how everything behaved. Who's in?

    I'm sure some of the various religions will be glad to join your thinking (if they aren't already there).

  • by Anonymous Coward on Thursday May 23, 2013 @12:52AM (#43800353)

    Well, so quantization of energy is wrong then? If you can have "fractional photons", then the Rayleigh-Jeans formula is completely correct. Never mind that it predicts that all blackbodies should be emitting radiation with infinite power.

  • by VortexCortex ( 1117377 ) <VortexCortex&project-retrograde,com> on Thursday May 23, 2013 @01:06AM (#43800405)

    The world is made of 4 basic elements, earth, air, fire, water.... No, scratch that, there are a bunch of elemental stuffs, the most holy of which is quicksilver, the universal element... Wait, no, there are over a hundred chemicals with different properties. Ah, look, see, there are atoms, you know, and inside these atoms you have electrons, protons, and neutrons -- See, that's what gives the atoms their properites -- And, wait, the sub atomic particles are made of Quarks, and -- No, there's a zoo of particles, and fields and they all interact in these little quantized packets / waves, Quantum Physics -- No, wait the quanta.......

    The rabbit hole is very deep indeed. Better tools show us finer structure. I agree. It would be exceedingly arrogant and foolish to think of light as "photons". We have only approximations, and they are always a bit wrong.

  • by quax ( 19371 ) on Thursday May 23, 2013 @01:15AM (#43800429)

    It's a common misconception that QM as a theory of the microcosm is somehow more general and accurate than SR. Yet, the derivation of SR does not even require the constance of light speed (although that's the route that Einstein oribinally followed), but can be derived from very obvious first principles [ist.utl.pt].

    And this is a key difference to QM where this still hasn't been accomplished (despite the theory being such a fantastic empirical success story). Of course as far as empirical evidence goes SR also has a spotless record (which is why the CERN faster than light brewhaha was pretty much a forgone conclusion [wavewatching.net]).



  • Before and after (Score:3, Insightful)

    by Taco Cowboy ( 5327 ) on Thursday May 23, 2013 @03:37AM (#43800877) Journal

    Question: Within the context of quantum mechanic, what is the behavior of TIME ?

    What I read from TFA is that they observe a certain particle at the before time frame, and then compare it with another particle at the after time frame, and found some "entanglement"

    What if the experiment is carried out on the reverse --- someone checking out a particle at the after time frame and then, some others compare it with another particle at the before time frame and see if they entangle or not

    I do understand that experiment that I have just described can't not happen with the limited technology that we have, for the after can not happen _before_ the before

    That's why I am falling back to my original question --- what is the behavior of TIME within the context of quantum mechanic ?

    Can an "after" happen _before_ a "before" ?

  • by ledow ( 319597 ) on Thursday May 23, 2013 @05:46AM (#43801199) Homepage

    The problem is that to be accepted in an area of science that's basically nothing more than a consequence of the maths, you have to show the maths that generate the results you expect.

    I'm a mathematician. I don't claim to understand 1% of 1% of quantum mechanics at all. But it comes from a mathematical model that happens to have real-world consequences that are weird and wonderful. When we then tested for those consequences, we found out that they exist in nature. Which, to a scientist mind, kind of hints that the maths must have been at least somewhat correct (or at least on the right lines).

    I have my own understanding and theories, but I would also have to state, quite clearly, that quantum physics isn't really "physics". This isn't Newton seeing an apple fall and realising there's a force at play. This is someone (probably THE most famous genius) sitting down for decades with almost unsolvable equations that make absolutely no sense until they realise that it works if you have 11 dimensions, or if space and time are two different elements of the same thing, etc. And that was back in the 1900's when quite a lot of physics and maths we enjoy now didn't even exist.

    Then you go out and measure in real life and you find that, actually, it turns out that your theory fits what happens in the world, not the other way around.

    As such, I don't for a second think that I can just posit a hypothesis (theory is a slightly stronger word in any science) and have any concept of if I'm talking gibberish or not. The maths of quantum mechanics is horrendous and complicated and quantum theorists spend more time in front of the blackboard than they do the LHC.

    If you wish to contribute, even if you don't intend to be taken seriously, it's only proper to get yourself a decent grounding in not just "hey, there's something smaller than an electron and weird stuff starts to happen at that scale, I bet I can guess what else happens", but in WHY that's so and HOW we got to that point. And in anything quantum, that means understanding the maths behind it.

    As someone with a degree in maths, I tell you now, you're going to need a decent grounding in quite a lot of basic physics and huge amounts of maths and that "real world intuition" will basically be next-to-useless until the very end. That's not to mention the level of things like calculus and linear algebra you'd need to even get close to learning how we got to all of the old "wrong" models, let alone the newer ones.

    This doesn't mean that wild ideas and theories have no merit, it's just that you're theorising about something that you probably don't understand the basics of. I know I don't. And I *can* read the mathematics and, given enough time, understand it.

    It just comes across to any mathematician or physicist as someone who is looking at a car for the first time and saying "You know, I bet if you made the whole thing ten times bigger, it would go even faster" or "If it goes that fast with four wheels, imagine what it'll do with 10!".

    In a way it reminds me of the Moon conspiracy theorists. They can come up with a million weird and wonderful things that intuition says "must be wrong". But it turns out that a few simple tests or bits of maths show them to all be nonsense. "The shadows are wrong" - fine, go out into the street on a sunny day and try hard to replicate them. If someone can replicate something that's "wrong" in the space of ten minutes, then maybe you are reading far too much into the image, or commenting on something you just don't understand.

    https://en.wikipedia.org/wiki/Introduction_to_quantum_mechanics [wikipedia.org]

    Seriously, just on that page there are some 16 equations, and that's not even a millionth of what you need to understand where those equations come from.

    Honestly, I DON'T understand quantum mechanics at all. I believe it, because it's accepted as the best self-consistent theory we have that has made verif

  • by painandgreed ( 692585 ) on Thursday May 23, 2013 @11:59AM (#43803755)

    Dark energy - a term coined to hide the fact that "we don't know".

    It's not a term to hide the fact that "we don't know", it's a term to punctuate that "we don't know". If we were really trying to hide stuff, we'd define it as stuff we already know about rather that come up with a new term (like the MOND guys are doing with dark matter).

Adding features does not necessarily increase functionality -- it just makes the manuals thicker.