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

Posted by samzenpus
from the time-after-time dept.
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.
    http://i.imgur.com/AUXb2N9.gif

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

    • Re: (Score:2, Insightful)

      by Laxori666 (748529)
      +1
    • Re: (Score:2, Insightful)

      by Anonymous Coward

      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.

      • Observation vs model (Score:3, Interesting)

        by Anonymous Coward

        If I had a machine, and it could only see the large circles, then all I would see is the large circles.
        If I then made a model of how the large circles appear and disappear, that model would be correct, it would fit the data, it would show the probability of the circles appearing as they jump around. Those circles will jump, they'll go backwards in time, they'll do kinds of weird things.
        So my equations all work, and my model of jumping circles works, ergo my model is correct?

        Except it isn't, its a function o

    • by VortexCortex (1117377) <VortexCortexNO@S ... t-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.

    • Well, I tend to think of quantum mechanics as proving the universe functions on call-by-need [wikipedia.org], with faster than light being the lack of support for mutation. Entangling then is really just call-by-need evaluating out a circumstance backwards far enough to note that when two waves/particles/whatever were at the same place, they had to have certain exclusionary properties (for the article, one photon was polarized vertically and the other horizontally) which cause the interpretation of entanglement.

      Of course,

    • by bug1 (96678)

      Dude, its, like, totally real, man.
      The photon is chillin with the physicists at an event in the parallel university after it went through teh wormhole.

      Can i have my grant money now ?

    • by tonywestonuk (261622) on Thursday May 23, 2013 @02:31AM (#43800681)

      I believed as you did. Then I read this http://quantumtantra.com/bell2.html [quantumtantra.com] - Its like Quantum physics , without the maths, and for the it literate.

      Changed my ideas on what QM was all about.

      Go read it. Seriously.

      • Oh, once you've read it, if you can code, go try making a program to simulate whats going on.... Try it. At some point you'll come to the conclusion that something really weird is happening.

    • by cripkd (709136)
      OMG, is that a photo of how light really looks?
  • Science (Score:5, Funny)

    by MyLongNickName (822545) on Thursday May 23, 2013 @12:20AM (#43800219) Journal

    At some point, science just got too weird. We had this nice model of the universe with atoms, some laws of motion and thermodynamics. The universe was basically a giant billiards match. It made sense. It was easy to explain. Then we get into quantum mechanics and everything is crap shoot. Multiple universes. Particles that behave differently when being observed. Spooky action at a distance.

    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?

    • Re: (Score:3, Insightful)

      by Nyder (754090)

      ...

      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 gagol (583737)
        Aren't most of them stuck at this flat earth thing and trying to convince the rest of the town their flat earth theory is the only one worth worshipping?
    • Re:Science (Score:5, Funny)

      by VortexCortex (1117377) <VortexCortexNO@S ... t-retrograde.com> on Thursday May 23, 2013 @12:42AM (#43800315)

      At some point, science just got too weird. We had this nice model of the universe with atoms, some laws of motion and thermodynamics. The universe was basically a giant billiards match. It made sense. It was easy to explain. Then we get into quantum mechanics and everything is crap shoot. Multiple universes. Particles that behave differently when being observed. Spooky action at a distance.

      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?

      That's what you said last time. Look what it got us? We're back to quantum physics AND we have nuclear weapons. Are you really ready to risk Universe hopping again?

    • Re:Science (Score:5, Funny)

      by Anonymous Coward on Thursday May 23, 2013 @12:44AM (#43800323)

      Nature and nature's laws lay hid in night;
      God said "Let Newton be" and all was light.
      It could not last; the Devil shouting "Ho!
      Let Heisenberg be!" restored the status quo.

    • Without quantum physics the cameras, fast CPU, GPUs and high speed communications that help me cope with my solitude at night wouldn't exist. Count me out brah.
    • Re:Science (Score:5, Funny)

      by fightinfilipino (1449273) on Thursday May 23, 2013 @02:02AM (#43800567) Homepage

      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?

      the Republican Party? large swaths of the American Bible Belt? Scientologists? Liberal Arts majors? Michio Kaku?

    • by jamesh (87723)

      At some point, science just got too weird. We had this nice model of the universe with atoms, some laws of motion and thermodynamics. The universe was basically a giant billiards match. It made sense. It was easy to explain. Then we get into quantum mechanics and everything is crap shoot. Multiple universes. Particles that behave differently when being observed. Spooky action at a distance.

      Douglas Adams had some very wise words on this subject, the implied conclusion being that scientists studying the universe are making it more complicated.

      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?

      Maybe you could go all the way back to when the universe began, 6000 years ago? But don't look back or you might get turned into a pillar of salt or something like that.

    • "I find X to be strange" is another way of saying "I'm pretending that I live in a magical, X-free fantasy world.". There is no such fantasy world and never has been. Nature doesn't care if your brain is mis-configured.

      When we get a result that's unexpected, we have an opportunity to deepen our understanding. That's science. When we get a result that's "strange", we're being contrary to our own knowledge. That's not science; I'd say it's more like religion.

    • by peragrin (659227)

      Science is always weird. 100 years ago atom weren' known exist. electricity was some wierd etheral vapor. besides atoms and laws of motion and thermodynamics only cover somethings. we kept noticing funny results at the edge cases. The farther down we go the funnier the results get.

      Eventually we will find out that all this quantum stuff actually makes sense and the funny properties are the results of us using planets the size of mars to figure out where the earth is. (relatively speaking).

    • by houbou (1097327)
      Ok, then bye bye warp drives! :)
  • by girlintraining (1395911) on Thursday May 23, 2013 @12:21AM (#43800227)

    Hey guys, Einstein just called me using GravePhone(tm) and he had the following to say:

    "Okay, maybe God does play dice, but I still stand by the law of conservation. God doesn't just make shit up. Now if you'll excuse me, Aristotle wants some one on one on the basketball court."

  • It looks like quantum teleportation meets delayed choice.
  • by quax (19371) on Thursday May 23, 2013 @12:49AM (#43800341)

    Special Relativity makes quite clear that if two particles are spacelike [wikipedia.org] separated when measured, that the concept of "instantaneous" is devoid of meaning.

    If you have this kind of distance than you will have just one special reference frame where this is true, and infinite more where the events are arbitrarily separated in time. This is already at the core of the EPR paradox [wikipedia.org].

    I.e. that you can have entanglement across time follows trivially from SR and the EPR paradox.

    It's just astounding how many times the very same insight can get repackaged and sold as new.

    • by avgjoe62 (558860) on Thursday May 23, 2013 @12:58AM (#43800377)

      It's just astounding how many times the very same insight can get repackaged and sold as new.

      And that my son is why you will never work for the patent office.

    • 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]).

      .

       

    • by c0lo (1497653)

      Special Relativity makes quite clear that if two particles are spacelike [wikipedia.org] separated when measured, that the concept of "instantaneous" is devoid of meaning.

      If you have this kind of distance than you will have just one special reference frame where this is true, and infinite more where the events are arbitrarily separated in time.

      While the above is true, I wonder how is this relevant to the issue at hand?
      I mean: who the hell mentioned something about instantaneous?

      TFA:

      to begin, researchers zap a special crystal with laser light a couple of times to create two entangled pairs of photons, pair 1 and 2 and pair 3 and 4.

      1. First zap - they create (1,2)
      2. Next zap (delta(t)>0) in the same space (delta(r)==0): they create (3,4)
      Seems to me they are working in time-like conditions [wikipedia.org], aren't they?

      The experiment shows that it's not strictly logical to think of entanglement as a tangible physical property, Eisenberg says. "There is no moment in time in which the two photons coexist," he says, "so you cannot say that the system is entangled at this or that moment." Yet, the phenomenon definitely exists.

      My first read of TFA: the guys managed to "entangle" photons created at different times.
      But then... hang on... weirder-and-weirder : they entangled photons that don't even exist in the same ti

    • by jouassou (1854178)

      Special Relativity makes quite clear that if two particles are spacelike separated when measured, that the concept of "instantaneous" is devoid of meaning.

      From TFA:

      Eisenberg emphasizes that even though in relativity, time measured differently by observers traveling at different speeds, no observer would ever see the two photons as coexisting.

      So the separation was timelike, not spacelike.

  • by NewtonsLaw (409638) on Thursday May 23, 2013 @01:32AM (#43800467)

    Some time ago I gave some thought to the apparent anomalies and strangeness of the quantum world.

    Here's what I came up with as a theory It's all about time [aardvark.co.nz]

    Comments would be welcomed from all the (real and wannabe) quantum physicists out there.

  • by Y.A.A.P. (1252040) on Thursday May 23, 2013 @01:37AM (#43800485)

    When you read the article, this isn't actually too controversial. All that's being done is changing the timing of of when the measurements are taken and when the intermediate photons become entangled. It's really just using the entanglement process to spread out the time over which the quantum state data is transmitted. You basically have a quantum data historical record.

    I can certainly see this opening up useful new capabilities in quantum computing and measurement of quantum phenomena, but it doesn't change our understanding of quantum events and how they interact with our "everyday notions of space and time.".

  • Superposition, wave function collapse and other quantum effects are supposed to govern everything. But I don't seem to recall any such weird experiments that do not involve any particle traveling slower than the speed of light.

    Are there any such demonstrations that involve only interactions between particles having nonzero rest mass?

    • The double-slit experiment can be done with electrons and atoms.
  • ????

  • by multatuli (740516) on Thursday May 23, 2013 @03:31AM (#43800867)

    Yes! Subspace communications!

  • by master_p (608214) on Thursday May 23, 2013 @03:40AM (#43800895)

    According to the article, particles 1 and 4 do not coexist. Therefore, one must be destroyed before the other is created.

    But if 1 is destroyed before 4 is created, then the entanglement of 1 and 2 is broken before 3 and 4 are created (because 3 and 4 are created together, and then 2 and 3 are entangled).

    So, by the time 2 and 3 are entangled, 1 does not exist, because 3 already exists and is entangled with 4.

    The question that arises is then how do they know that 1 and 4 are entangled?

    It could simply be that 1 and 4 show the same state when measured, because 1 and 2 were entangled, then 3 and 4, then 2 and 3. Which means that whatever entanglement existed between 1 and 2 will exist between 1 and 3 and 1 and 4, even if 1 does not exist.

    That does not mean particles are entangled across time. It may mean that entaglement is simply peristent and transmiitable.

    Most probably there is a misunderstanding somewhere between the announcement and the article, so please anyone that knows more, elaborate.

  • Entanglement exists outside of reference frames. So, it exists across time.

    This means that there is a super reference frame which includes all possible frames and allows for things to persist (and perhaps move) across time.

  • Now I understand Einstein's wild hairdo....

    I think the rabbit hole may be a wormhole without the other end!

    *head asplodes!*

  • by senorpoco (1396603) on Thursday May 23, 2013 @04:46AM (#43801047)
    They could only be connected to other particles that existed in their lifetime and then they would have to perform a good deed before being able to connect to a different particle. Oh boy
  • it is possible that life is a mixture of quantum state and this dimension. Thus the reason for being able to think and have a feeling of self?

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