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Scientists Achieve Direct Counterfactual Quantum Communication
- deleted 9y ago[deleted]
- ChuckMcM 9y agoWow, I remember reading a paper on this as a theory about 10 years ago in Scientific American. At the time I don't recall the paper actually having a way to do the experiment, it was in the category of 'look what the math says is possible'.
- NikolaeVarius 9y agoTitle: Scientists Achieve Direct Counterfactual Quantum Communication For The First Time. Article: "The results will now need to be verified by external researchers to make sure what the researchers saw was a true example of counterfactual quantum communication." Okay then
- gus_massa 9y agoThis is usual. I don't know why they explained it here. [1] This result was published in a peer review journal. It means that two or three experts read the article and found no evident flaw and think that it has enough details to make the experiment in another laboratory [2]. They didn't go to the laboratory and unbolted every piece to double check the setup, or make a copy in their own laboratory to check the experiment. So until two or three more laboratories try this and a few variations, this is still doubtful, but there is a good chance that this is true. [2] Usually the papers don't have enough information. You have to guess and email the authors and cross your fingers to reproduce the result. [1] My guess is that they explained this because the result is very unintuitive.
- dflock 9y agoAs you sort of imply in your second footnote, "has enough details to make the experiment in another laboratory" often _isn't_ a requirement to pass peer review, sadly.
- semi-extrinsic 9y agoIt's frequently a loose requirement; trouble is to know how much information is necessary to replicate, you typically have to do the actual replication (and iterate with authors over details). Not to mention that journals tend to dislike overly long papers.
- deepsun 9y agoThat's probably why it's included in "fakenews" category on https://github.com/StevenBlack/hosts https://github.com/StevenBlack/hosts
- deleted 9y ago[deleted]
- justifier 9y agofrom the abstract > Intuition from our everyday lives gives rise to the belief that information exchanged between remote parties is carried by physical particles. Surprisingly, in a recent theoretical study .. quantum mechanics was found to allow for communication, even without the actual transmission of physical particles. ok, does this also mean that communication is free from restraints that particles suffer.. as in would this allow faster than light communication?
- JshWright 9y agoThe speed of light isn't a property inherent to physical particles. It is far more fundamental than that. Check out the PBS Space Time channel. They have a number of excellent episodes on the speed of light, causality, etc...
- justifier 9y agoyeah, i'm sorry i should have been more clear what i am interested in is: i understand that solely utilising quantum entanglement, a ftl phenomenon, one is unable to communicate classical information but does this method utilise the zeno effect to afford this communication by controlling when to cease and reinstate the systems evolution? two parties with entangled particles within quantum systems agree on a baud rate and the transmitter alters the systems evolution until it takes on a desirable state then arrest the evolution until the next scheduled modulation, then evolve the state to the next desired expression, wait for the next modulation, and on and on effectively the information transfer would adhere to causality, the observer would be subject to the baud rate, but the distance traveled between the parties could be greater than one that light could travel within that baud rate
- ajkjk 9y agoEr. Quantum entanglement is not a faster than light phenomenon. Or, at least, describing it as such is rather pointless. It's no more 'faster than light' than 'realizing something about a faraway place' is.
- politician 9y agoDoes it require entanglement? No. > Direct counterfactual quantum communication on the other hands relies on something other than quantum entanglement. Instead, it uses a phenomenon called the quantum Zeno effect. Does it violate the speed of light? No. > It works based on the fact that, in the quantum world, all light particles can be fully described by wave functions, rather than as particles. So by embedding messages in light the researchers were able to transmit this message without ever directly sending a particle. Is this a sleight of hand? I don't know... ("New system of angular motion doesn't require radians! Uses 'degrees' instead.") > ...all light particles can be fully described by wave functions, rather than as particles...
- pavement 9y agoAbstract for paywalled PNAS paper: http://www.pnas.org/content/114/19/4920.abstract http://www.pnas.org/content/114/19/4920.abstract The image transmitted was a monochrome bitmap graphic of a Chinese knot: https://upload.wikimedia.org/wikipedia/commons/thumb/f/fb/Eight_chinese_knots.jpg/1200px-Eight_chinese_knots.jpg https://upload.wikimedia.org/wikipedia/commons/thumb/f/fb/Ei... ...no resolution noted in the abstract, but probably small and pixelated, since it was serialized as photomultiplier clicks.
- devrandomguy 9y agoWe are receiving a wireless telegraph! It is from Marconi. He wants us to get off his lawn.
- hasenj 9y agoThey still transmitted light, they just called it a wave instead of a particle. Am I missing something?
- tbrownaw 9y agoYes, you're missing whatever's hidden behind the journal paywall. It's been way to long since my one quantum physics class, but looking at the pretty pictures I think they got their photon to interfere destructively with itself over the entire length of the transmission channel between a pair of beam splitters. Which I don't think is possible with ordinary waves (say in water), which I suppose is probably what the big deal is.
- TheOtherHobbes 9y agoIf you go Full Copenhagen and start thinking about QM as a calculus of probability densities in physical systems it begins to make a lot more sense than trying to think about it as an impossibly weird version of Newtonian mechanics for waves+particles+wtf. It means you can stop playing "Where's the photon?" and accept that these experiments are doing spatially distributed probabilistic computing. In this view there is no photon - there's only a map of possible photon-like event positions distributed in spacetime, and one or more end-points tuned to pick up photon-like events by sampling the map at specific spacetime locations. The weird part is the way that interactions between the map distributions and the end-points are completely unintuitive, and you can do neat tricks like constraining probabilities by repeatedly connecting to an end-point, and creating dead areas where the probability of an event is zero but which don't "block" events around them. That just emphasises that the Newtonian-ish view is the wrong model. The right view is still TBD, but it seems to be some kind of holistic summary view that somehow - no one can even begin to guess how - creates a map by integrating over all possible interactions. This is not what we're used to, but discovering that reality doesn't do what we expect is the point of science, so that's not a bad thing.
- varjack 9y agoPlease stop waving your hands. I prefer the deBroglie-Bohm interpretation where you have both a particle and a wave. Changing the shape of the wave by changing site B setup changes where the particle ends up, even if the particle does not leave site A. (However, for this experiment to work, there should be a chance for the particle to travel from A to B, otherwise the pilot wave won't travel either)
- jimmies 9y agoIf you want to read the paper, type in your address bar sci-hub.cc and a slash, and then paste the DOI after the slash.