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Science Technology

Einstein's 'Spooky Action' Has Been Demonstrated On a Massive Scale For the First Time (sciencealert.com) 278

schwit1 shares a report from ScienceAlert: For the first time, scientists have managed to show quantum entanglement -- which Einstein famously described as "spooky action at a distance" -- happening between macroscopic objects, a major step forward in our understanding of quantum physics. Quantum entanglement links particles in a way that they instantly affect each other, even over vast distances. On the surface, this powerful bond defies classical physics and, generally, our understanding of reality, which is why Einstein found it so spooky. But the phenomenon has since become a cornerstone of modern technology. Still, up until now quantum entanglement has only been demonstrated to work at the smallest of scales, in systems based on light and atoms, for example. Any attempt to increase the sizes has caused problems with stability, with the slightest of environmental disturbances breaking the connection. But new research changes all of this, by demonstrating that this "spooky action" can indeed be a reality between massive objects. We're not talking massive in the black hole sense but in the macroscopic sense -- two 15-micrometer-wide vibrating drum heads. And the next step will be to test whether those vibrations are being teleported between the two objects. The research has been published in the journal Nature.
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Einstein's 'Spooky Action' Has Been Demonstrated On a Massive Scale For the First Time

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  • News to me (Score:5, Insightful)

    by Anonymous Coward on Thursday April 26, 2018 @10:23PM (#56511053)

    Entanglement is a cornerstone of modern technology? Say what?

  • "Massive" scale? (Score:5, Informative)

    by UnknownSoldier ( 67820 ) on Thursday April 26, 2018 @10:27PM (#56511069)

    Massive is relative.

    15 micrometer is only 0.015 mm. Massive would be 1,500 meters.

    0.015 mm is massive compared to 10^-10 m.

    Context matters.

    • by Presence Eternal ( 56763 ) on Thursday April 26, 2018 @10:36PM (#56511103)

      I think that's something like 60 times larger than modern transistor architecture.

      Given we're used to entanglement involving single atoms, it is astonishing in size.

      • Re: "Massive" scale? (Score:5, Interesting)

        by cb88 ( 1410145 ) on Thursday April 26, 2018 @10:47PM (#56511149)
        technically we have the capability to assemble single 1nm transistors since 2016... you can fit alot of transistors in 1um even at larger scales. I wonder what happens though when you entangle two circults.

        http://newscenter.lbl.gov/2016/10/06/smallest-transistor-1-nm-gate/
        • by mikael ( 484 )

          It would be interesting to see if they could quantum entangle two MEMS resonant oscillators. Change the amplitude on one and the other changes amplitude. But how do you entangle them in the first place - beams of quantum entangled photons?

          • Re: "Massive" scale? (Score:5, Informative)

            by Lanthanide ( 4982283 ) on Friday April 27, 2018 @12:04AM (#56511439)

            Entanglement is poorly understood. You don't "change one and the other changes".

            Entangled particles vibrate/spin/whatever the same way. You don't know what that way of movement is until you measure it. When you measure A and discover it to be spinning clockwise (or whatever), then you also know that B is spinning clockwise. Both A and B were spinning clockwise from the time they were entangled, there is no "change" involved, just the fact that measuring the spin of A lets you also know the spin of B.

            The bottom line is you CAN'T use this to transmit information instantly across distances: if it were the case that you could cause B to spin the same way as A by changing A's spin, then you could transmit information. That's not how entanglement works.

            • by novakyu ( 636495 )

              Both A and B were spinning clockwise from the time they were entangled

              You are describing a hidden variable theory, which has been ruled out by Bell's theorem [wikipedia.org] and subsequent experiments (well, the local version has been, and no one but Bohm is kooky enough to believe in non-local theories).

              • Re: "Massive" scale? (Score:5, Interesting)

                by HiThere ( 15173 ) <{ten.knilhtrae} {ta} {nsxihselrahc}> on Friday April 27, 2018 @02:13AM (#56511767)

                Sorry, but Bell's Theorum only rules out local hidden variables. Non-local hidden variables are still within the bounds of the theory. But they're a bit weird, as they're non-local in time as well as space. I don't think the theory puts a bound on *how* non-local they can be, but a hypervolume of light years would be difficult to test. (OTOH, I'm no expert in this area. I believe that Boehm thought they were global rather than just non-local...but that was decades ago, and things may have been found out since then. OTOH, perhaps it's really implied by the theorum.)

                Still, my favorite interpretation is EWG multi-world rather than hidden variables. For parsimony I add a supposition that I can't justify which is that in addition of the state space transitioning to all possible futures, it also arrives from all possible pasts, giving a lattice rather than a tree. I've got a vague feeling that this may determine the existence and strengthening of dark energy since all the pasts still exist in the hypervolume of the universe. You just can't go into the past because all of your particles have an inertial velocity along the time axis resulting from the big bang. If this *can* be made sensible, somebody much better at that kind of math than I am would need to tackle it. But it explains the rotation of the space-time axis as you accelerate near to the speed of light, or at least I think it does. I'm not quite clear how many dimensions this idea of the universe would require, but I'm sure it's less than the 16 that were used in deriving relativity, so it could probably fit into the same framework.

            • by jetkust ( 596906 )
              I don't know all that much about Quantum theory, but it does appear that you are contradicting what quantum entanglement is about. Quantum entanglement is not two particles spinning the same way, but two particles that are the opposite of each other and when combined cancel each other out (when combined have a spin of zero). If you could change the spin of A then the spin of B is the opposite. That IS transmitting information.
              • Re: (Score:3, Insightful)

                by Lanthanide ( 4982283 )

                Changing the spin of A breaks its entanglement with B.

                Based on current knowledge, you cannot transmit information using entanglement.

              • by HiThere ( 15173 )

                Well, not quite. You change the state of an atomic particle when you measure it, but that's because your sensor is so gross when compared to the mass of the thing being measured. I'm not sure what would happen with things microns in diameter.

                Also, you don't change the state of the other particle, by measuring one particle you KNOW something about the state of the other particle. You can't really say you've changed it, since you previously had no idea of its state. And in the traditional examples by sele

                • There is no way to measure things without breaking the entanglement. Even the interaction with a photon breaks. That's basic quantum mechanics of coupled states.
                • I'm not an expert, but I won't let that stop me.

                  We know that there is no local determinism, from Bell's Theorem and subsequent experiments. Those sorts of theories are hidden-variable theories. It's possible that everything's determinate on a global scale, but that goes a bit too far for most physicists. If particles were multidmensional things that have apparently random behavior when projected into our spacetime, the multidimensional things themselves aren't deterministic.

            • by Memnos ( 937795 )

              Yes, and we probably never will, except at a great expense of energy. C, well it's a pretty stern barrier. It's the basic ratio of space to time, and there's no getting around it that we can see.

            • by AmiMoJo ( 196126 )

              Entanglement is useful for created shared encryption keys that cannot be undetectably intercepted. While you can't control the information being sent (it's random, which is fine for encryption keys) you are transmitting that information to a remote receiver.

            • Both A and B were spinning clockwise from the time they were entangled, there is no "change" involved, just the fact that measuring the spin of A lets you also know the spin of B.

              Actually, no. A key property of quantum particles is that their quantum states are undetermined until locked down by measurement.

              So at the time of entanglement, A will have undetermined spin S and B will have undetermined spin S'. Once S and S' are measured, they will turn out to be strongly correlated. Measuring S will randomly determine its value (and that of S') within the probabilities set by the wave function of the entangled system (A, B). Because the wave function collapse is random, it's impossible

              • Yeah, you're right.

                I was just giving an off-the-cuff answer based on YouTube videos I've watched on the subject (coincidentally just watching one now about Bell's theorem), in response to the frequently-seen misunderstanding that entanglement could be used to transmit information.

                Saying "Both A and B were spinning clockwise from the time they were entangled" was my (poor) explanatory way of showing how measuring the spin of A cannot 'change' the spin of B - we've discovered some information about A and thro

            • Re: (Score:3, Informative)

              by swillden ( 191260 )

              Both A and B were spinning clockwise from the time they were entangled, there is no "change" involved, just the fact that measuring the spin of A lets you also know the spin of B.

              Nit: They have opposite spin, not the same spin.

              You're citing the "hidden variable" theory, which has been definitively disproven. An oversimplified-to-the-point-of-being-wrong explanation: There are multiple possible axes of measurement and it's impossible for the two particles to have opposite spin in all of them. Yet when we measure one particle in one axis, then measure the other in the same axis, we find that they always have opposite spin, regardless of which axis we picked.

        • That only refers to the size of the Gate, not the width of the transistor which is the dimension that is used when manufacturers specify "size".

      • A drop of water 0.015mm across contains about 100 trillion molecules.

      • I think that's something like 60 times larger than modern transistor architecture.

        LOL! You you made my day, thanks!

    • Re: (Score:2, Interesting)

      by TWX ( 665546 )

      Massive is relative.

      15 micrometer is only 0.015 mm. Massive would be 1,500 meters.

      0.015 mm is massive compared to 10^-10 m.

      Context matters.

      15 micrometers is bigger than the cross-section of a single-mode fiber optic cable core.

      If they can make this reliably work this could revolutionize communications. Manufacture two transceivers that are quantum-entangled, so four 'drumheads', one for each direction. Install these in the manner of SFPs in network switches or routers. Use them with no medium between them at whatever distance one needs. No more horizontal boring, no more trenching, no more fiber, no more intermediate points as repeaters, n

      • by sconeu ( 64226 )

        No dice. Information still cannot be transmitted over the FTL channel.

        • by bondsbw ( 888959 )

          Given this, why do they feel the need to test vibrations?

          two 15-micrometer-wide vibrating drum heads. And the next step will be to test whether those vibrations are being teleported between the two objects.

          • by Megol ( 3135005 )

            Because they may learn something? Because having an entangled near light speed channel would be very useful? Because they have some time left until vacation time and have to do something?

            I couldn't understand anybody that wouldn't want to do that experiment given the equipment...

        • You left out a word at the end of your sentence. "Yet" With the world falling apart all around us I take solace in the fact that there are people actually working on pushing theoretical concepts off the whiteboard and into real world applications.

          • by TWX ( 665546 )

            And the funny thing about it is that we already have lasers produced in the millions that could probably affect change on the 'drumhead' and could read the 'drumhead'.

            I would be very amused if they managed to squeeze such transceivers down to SFP-size.

            It took Corning and partners decades to develop fiber optic cabling, and it has taken decades to refine it down to 9 micron cores. For 40 Gigabit I believe the effective distance is 40Km, a little under 25 miles. That means every 25 miles there has to be som

          • Even theoretically, you cannot transfer information faster than light.

            • by TWX ( 665546 )

              Where did I say it would be FTL?

              How would not being FTL make it worse than current communications systems?

              Even if it's not FTL, as long as it's basically as fast as light, it should be a pretty damn awesome replacement for all that fiber optic cabling.

              • You cannot entangle two objects while they are at a distance. You entangle them first, then separate them, then you measure them. The measurements are random but correlated. You cannot, not even theoretically, transfer information over the channel at the time of measurement.

    • by aquabat ( 724032 )
      That's heavy, man. What's your conversion formula from meters to kilograms?
    • And in that context "massive" probably just means "has mass", i.e. inertia is of central importance.

      Apparently the slashdot submitter misinterpreted "massive" to implicate scale as in "really heavy".

      Of course 10^12 Atoms is quite a step up from single atoms or simple molecules.

  • Hey, maybe we're on the verge of (re?)discovering magic is real and something we can harness!

  • Soooo spoooooky? (Score:2, Informative)

    by Anonymous Coward

    >which is why Einstein found it so spooky

    Which is why you have no clue what Einstein was talking about. He wasn't spooked you knucklehead, he was mocking it as magic.

  • by Pulzar ( 81031 ) on Thursday April 26, 2018 @10:43PM (#56511127)

    But the phenomenon has since become a cornerstone of modern technology.

    Did I miss a bunch of modern technology development?

    • But the phenomenon has since become a cornerstone of modern technology.

      Did I miss a bunch of modern technology development?

      Perhaps they actually meant the bleeding edge of modern technology, like quantum computers.

      Strat

    • "Cornerstone" is probably stating it a bit strongly, but superconductors are mainstream now, and SQUIDs [wikipedia.org] in particular are very important to the modern world.

  • by Anonymous Coward on Thursday April 26, 2018 @10:44PM (#56511133)

    >"In quantum teleportation, properties of physical bodies can be transmitted across arbitrary distances using the channel of 'spooky action at a distance'," says one of the team, Caspar Ockeloen-Korppi from Aalto University in Finland.

    This is a fundamental misunderstanding of entanglement. It is not a mechanism for teleportation, it is a dual destination verification mechanism (ie. one must be opposite the other if they maintain entanglement). You cannot set the value at one end and have it appear on the other.

    • by raymorris ( 2726007 ) on Thursday April 26, 2018 @11:00PM (#56511203) Journal

      For those of us who don't know enough to really understand it, we can think of it like a cat.
        You pull the cat's tail on one end, the cat meows on the other end. Quantum entanglement is exactly like that. Except there is no cat.

      (The above is an old description of radio, often attributed to Einstein. Doesn't sound like Einstein's sense of humor, though.)

      • by gotan ( 60103 )

        For those of us who don't know enough to really understand it, we can think of it like a cat.

        You pull the cat's tail on one end, the cat meows on the other end. Quantum entanglement is exactly like that. Except there is no cat.

        No it isn't, because that would mean you could transmit signals by means of quantum entanglement, which you can't.

        It's more like: if you look at the lengthwise orientation of the cat and get to see the tail, then the nose must be on the other end and vice versa. But you also might want to look at the crosswise orientation of the cat, and if you get to see the left ear on your side, the right ear must be on the other side. Also the cat has the strange property, that if you know all about the lengthwise orien

    • Re: (Score:3, Informative)

      You are right about quantum entanglement. But the team member was talking about quantum teleportation, not just entanglement, and I suspect that you misunderstand the difference.

      'You cannot set the value at one end and have it appear on the other.'

      Right, about entanglement.

      'properties of physical bodies can be transmitted across arbitrary distances'

      Right, where the properties are quantum states.

      'This is a fundamental misunderstanding of entanglement.'

      No, it's not. Quantum teleportation depends on having an

      • Quantum teleportation requires a "classical" channel.

        This is also described in the WP-Article. I wonder if you really need to transfer 2 classical bits per qubit though.

        There are some quantum computer simulators out there with which one can "simulate" quantum teleportation.

        E.g. http://algassert.com/quirk [algassert.com] has a ready teleportation example under "Menu" with which one can play around.

    • "(ie. one must be opposite the other if they maintain entanglement)...."

      For those of us who are a little slow, how does one know entanglement has been maintained?

      • Good question (nothing 'slow' about it!). The short answer: Statistically.

        Longer answer: Suppose you prepare a system in a quantum state you suspect is entangled. By definition, that system will have parts that can be measured separately. Because the parts are entangled, some measurements of the parts will be correlated. A single measurement of the parts might show that the correlation is violated, in which case you've learned that the state is *not* entangled (possibly is was entangled but that entanglemen

  • Spooky! [youtube.com]
  • Damn (Score:2, Offtopic)

    by fahrbot-bot ( 874524 )

    I so wanted to make a "spooky action at a distance" dick joke, but they said "massive scale". :-(

    • It must be massless because otherwise it would be defying the law of gravity by standing up like that!

  • Two separated items simultaneously communicating/sharing state information/controlling each other? I thought light speed was the fastest the simulation could update. The Simulators get a new algorithm or swap out some chips or get a faster HD or something? Or no?

    • Good question.

      The angry "evangelists" will say to you "IT'S IMPOSSIBLE AND IF YOU DARE TO THINK THIS AGAIN I KILL YOU!!"

      I will say "we should find a way to test this, maybe send the same message over a long distance using the entanglement AND a conventional radio (or fiber) link to see if both messages arrives the same time?"
      • by Jeremi ( 14640 ) on Friday April 27, 2018 @12:58AM (#56511607) Homepage

        Or try this older-technology test, which is equivalent:

        1) Obtain two empty boxes
        2) Into the first box, place a red marble and a blue marble
        3) Put on a blindfold so you can't see anything
        4) While blindfolded, reach into the box with the marbles and take out one of the marbles, and put it into the other box
        5) Close both boxes and seal them shut
        6) Remove the blindfold
        7) Mail one of the boxes to Alpha Centauri
        8) When it gets there, open the box you didn't mail, and note what color marble is in it
        9) Enjoy the "faster than light communication" -- you just "instantaneously" learned the color of a marble located four light years away!

        • Yeah! What you said!

          Won't do any good, though. And don't forget the time reversal -- On alpha centauri and earth, people but the red and blue marbles in their respective boxes, they zip backwards in time (with rocket fuel magically appearing in space and being sucked up into the engine to store itself unoxided the tanks) to be opened by somebody wearing a blindfold so he can't see which marble was in which box who ends up with a red and blue marble in his hand. Like that, too.

          That's the part that most fo

        • You have two laptops, one of which has Windows installed, the other Linux. You give two Tesla drivers a laptop each and one of them drives to Mars. The one who switches on the laptop and finds it has Windows is the loser.
    • From what I've read, determining eg. the polarisation of one quantum entangled particle, the other changes as well, and it happens faster than if the effect of measuring propagated at light speed. Ars Technica had an article touching on this in 2012 [arstechnica.com]. Okay, that was the first I found and it doesn't seem very fulfilling.
    • by Trogre ( 513942 ) on Thursday April 26, 2018 @11:26PM (#56511291) Homepage

      Actual physicists, please correct me if I'm wrong:

      Yes it apparently is faster than light in a vacuum, but it doesn't seem to matter. The change in spin happens instantaneously at both places, but since you can't deliberately change the spin yourself, merely observe it, no information is actually propagated. Thus you're not transmitting anything faster than light, and the universe therefore doesn't explode.

      • Nobody knows how entanglement works. The mechanism might very well be faster than light communication but because *we* can't use it to transfer information faster then light, the rules of physics as we know them, get to live another day
      • Actual physicists, please correct me if I'm wrong:

        Yes it apparently is faster than light in a vacuum, but it doesn't seem to matter. The change in spin happens instantaneously at both places, but since you can't deliberately change the spin yourself, merely observe it, no information is actually propagated. Thus you're not transmitting anything faster than light, and the universe therefore doesn't explode.

        Are you sure about this part? if I had a laboratory for that, that's what I'd be trying to figure out how to do right now (and also how to read the state without destroying the entanglement in the process or causing an unwanted state change).

    • This is faster than light in a non-communicative way. If you shine a really powerful laser pointer at the moon and then flick your wrist you can make the red spot on the moon move from one side of the moon to the other faster than light... but you can't communicate FTL that way either.

    • by Megol ( 3135005 )

      Simulators?

  • Spooky action at a distance boils down to a simple thing really. Take a coin and slice it in half so that heads is on one piece and tails is on the other and don't look at it. Now put one piece in an envelope and send it to person A. Put the second piece in a second envelope and send it to the second person B. Now when person A opens the envelope and reads the value, They will also know the value that was sent to A. The information was encoded in the envelope before it left so it is not a mystery how t

    • The second to last sentence was supposed to read...

      Now when person A opens the envelope and reads the value, They will also know the value that was sent to B (B not A).

    • What you're talking about are hidden variables, and Einstein considered them as a way to explain away the spookiness. The problem is, people like John Bell came up with pretty ingenious ways of testing whether hidden variables are really responsible for the spookiness, and, in short, they aren't*. Veritassium actually has a pretty good explanation [youtube.com] of why hidden variables don't work.

      *Okay, local hidden variables (like those in your example) are ruled out. It is possible that hidden variables, that stretch ac

      • If I recall, John Bell was not a fan of the Copenhagen interpretation, was very interested in De Broglie-Bohm pilot-wave interpretation (using non-local hidden variables), and his theorem was built as a test of local-hidden variable theories - which have been ruled out by his theorem.
      • Some time ago I read a possible explanation for the entanglement that makes sense even though it leaves physicists ripping out their hair... That perhaps two entangled particles are, somehow, actually the same particle existing in two places at the same time.
    • Actually, not quite. For the analogy to work, each half of the coin is equally heads and tails until the measurement. Only the entanglement itself (i.e. that one is opposite the other) was encoded in the envelope to begin with.
      We might need another analogy. Consider Donald Trump and Hillary Clinton as entangled particles guaranteed to hold opposite views on any given topic. With Hillary in New York and Donald in Los Angeles, ask Donald a question about one of the few things he has no opinion on. Until you
  • Clarification needed (Score:5, Informative)

    by FranklinWebber ( 1307427 ) <franklin@eutaxy.net> on Thursday April 26, 2018 @11:42PM (#56511367) Homepage

    I find the summary in great need of clarification. Let me attempt to clarify it in the hope that will be useful to other readers.

    First, the linked article links to a much better summary written by one of the team members, Matt Woolley. I recommend you read it instead:
    https://theconversation.com/ex... [theconversation.com]

    Second, the summary conflates *mass* with *distance*. The experimenters claim to have entangled remarkably massive objects (compared to the mass of atoms, for example). But the summary says 'any attempt to increase the sizes has caused problems with stability' and that, taken literally, is not true. For example, here's an experiment from 1998 in which entanglement was maintained over a distance of kilometers:
    https://en.wikipedia.org/wiki/... [wikipedia.org]

    Finally, the summary claims 'a major step forward in our understanding of quantum physics' but I doubt that. It sounds to me like a major accomplishment but one that *confirms* our previous understanding of quantum physics in more massive systems.

  • I always thought quantum computing was mainly based on quantum entanglement. So is that wrong or is quantum computing simply a pie in the sky project topped with a lot of BS?
  • And quantum properties are always discreet state-changes, like flipping bits. There is no entanglement property that extends beyond a single degree of freedom; i.e. one single dimension. I've always thought that an interesting observation.
    • The physicists chose to describe their system in a convenient coordinate system, and usually work with very simple systems as well, e.g. those that have only two states like qubits.

      Sure one could work with more complex systems, atoms with higher spins or systems of multiple particles, but that would just make everything more complicated, when there's still much to learn from simple systems.

  • two 15-micrometer-wide vibrating drum heads

    Do they have any 15-micrometer-wide cowbells to go with those drums? They need more cowbell! Einstein was a huge fan of BOC.

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