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German Scientists Successfully Teleport Classical Information (upi.com)

Posted by BeauHD on from the beam-me-up-Scotty dept.

An anonymous reader writes from an article on UPI: Using a series of laser beams, a pair of German scientists teleported information without the transfer or matter of energy. "Elementary particles such as electrons and light particles exist per se in a spatially delocalized state," Alexander Szameit, a professor at the University of Jena, explained in a press release. Classical information is coupled using a process called "entanglement." "As can be done with the physical states of elementary particles, the properties of light beams can also be entangled," said research Marco Ornigotti. "You link the information you would like to transmit to a particular property of the light." Researchers used polarization to encode information within a laser beam, enabling the teleportation of information instantly and in its entirety without loss of time. Whereas quantum information and quantum systems describe particle properties that are inferred, classical information describes physical properties directly measured.

20 of 107 comments (clear)

  1. Let me get this straight by wierd_w · · Score: 3, Interesting

    They just figured out non-local data transmission at FTL speeds.

    They arent transmitting quantum states, they are transmitting polarization data, which can be used to encode classical information, and transmitted such classical information.

    This means that you can transmit from point A to point B, "instantly", as long as you can entangle the two points.

    Does this mean that causality is only a suggestion, or will the physical constraint of having to usefully entangle the two points save the day here?

    1. Re:Let me get this straight by Etherwalk · · Score: 2

      If they have figured out data transmission at FTL speeds (which is hard to tell just from the summary and without the right Ph.D.) then yes, that suggests a violation of causality, or at least a need to redefine it.

      However, it is much more likely (based on... the observed universe up to now...) that either something about the system predetermines the output at both locations, or that the output at one point is known to be distinct or the same as the other but that there is no way to influence what the outcome from point B will be from point A. In other words, they probably hid the causality and maybe they haven't quite figured out where they hid it yet.

      Fortunately, this is slashdot, so hopefully a pseudo-expert will actually follow the links and then translate for the rest of us.

    2. Re:Let me get this straight by michelcolman · · Score: 3, Informative

      They didn't figure out "non-local data transmission at FTL speeds".

      They figured out local transmission without loss of time, i.e. encoding information into the polarization of a light beam, instantaneously, but without bridging any distance.

      Quote: "With this form of teleportation, we can, however, not bridge any given distance," admits Szameit. "On the contrary, classic teleportation only works locally."

      The rest is just the usual hyperbole and Star Trek comparisons by people who don't know what they're talking about. "Teleportation works instantly across any distance!" – yes, but not that kind of teleportation. The kind that works across distances cannot be used to transmit information.

    3. Re:Let me get this straight by SoftwareArtist · · Score: 3, Informative

      No, the article was just written by a completely clueless person who had no idea what they were talking about. I looked up the original paper, and the answer is right there in the abstract:

      For many years, however, it has been implicitly assumed that this scheme is of inherently nonlocal nature, and therefore exclusive to quantum systems[...] We present an optical implementation of the teleportation protocol solely based on classical entanglement between spatial and modal degrees of freedom, entirely independent of nonlocality.

      This effect is, in their words, "entirely independent of nonlocality." The information is being transmitted through space in the ordinary way, traveling no faster than light. The person who wrote the summary just made up the part about "instantly" and "without loss of time."

      --
      "I'm too busy to research this and form an educated opinion, but I do have time to tell everyone my uninformed opinion."
    4. Re:Let me get this straight by jettoblack · · Score: 2

      I'm a big scifi nerd and I'd love for FTL travel/communication to be proven possible, but if it ever is, it likely won't be via quantum entanglement.

      Here's an analogy: We have a red ball and a black ball. We randomly put each one into a sealed box so that it's impossible to tell which ball is in which. I take one on my spaceship and fly away from you at top speed, you do the same in the opposite direction. When we're a light year apart, we both open our boxes. Mine is red, so I immediately know that yours must be black, and vice versa. We were able to determine the color of a ball 1ly away instantaneously, even though it would take at least a year for any message like "mine is the red one" to reach the other.

      However, this doesn't mean we can send information FTL. Even with an unlimited supply of balls, the best I can do for any particular ball is know that yours is the opposite color. I can't manipulate the color or choose the order in order to send information FTL, at least not without some side channel of communication which must necessarily happen at c or slower. (If the side channel communication was FTL then we'd just use that to communicate and skip the entanglement part.)

    5. Re:Let me get this straight by NewtonsLaw · · Score: 2

      How *dare* you bring facts into a Slashdot argument?

      Have you no pride at all?

      LOL :_)

  2. Re:Marco Ornigotti? by wierd_w · · Score: 4, Insightful

    We have people named all kinds of things in the US. They are still Americans.

    Germany is a cosmopolitan, modern industrial nation. There is no reason why a native born German citizen cannot have that name.

  3. Never any description by evanh · · Score: 3, Interesting

    I always check each of these type of news items, hoping one may attempt to explain how it works. Alas, no such luck yet again. :(

    1. Re:Never any description by wierd_w · · Score: 3, Interesting

      That's still very useful for a number of situations.

      1) Ship en-route to Alpha Centauri-- They entangle their transmitter and receptor beams at the launch, stay in realtime contact the entire flight. Flight takes many decades, but they stay in contact with earth in realtime. (as long as the beams never lose power, and thus stop being entangled.)

      2) SETI wants to talk to aliens in a target system. They send the rough equivalent of a modem's negotiation signal for however many years it takes for polarized light to get there. Hopefully, the aliens know about this kind of entanglement, and can entangle their own beam with the incoming polarized light. The aliens can now alter the polarization state of the beam on earth, and send a return message. The return message is received "instantly." Once the channel is open, realtime communication is possible.

      Neither of those is possible with traditional entangled photons.

    2. Re:Never any description by NormalVisual · · Score: 2

      1) Ship en-route to Alpha Centauri-- They entangle their transmitter and receptor beams at the launch, stay in realtime contact the entire flight. Flight takes many decades, but they stay in contact with earth in realtime. (as long as the beams never lose power, and thus stop being entangled.)

      My knowledge of physics is admittedly not as good as I'd like, but would this be subject to any relativistic effects? We don't have anything that can go a substantial fraction of the speed of light, but it seems it still might be a factor given that we have to account for these effects with the GPS satellites.

      --
      Please stand clear of the doors, por favor mantenganse alejado de las puertas
    3. Re:Never any description by Baloroth · · Score: 2

      That's not how it works. First, while once the aliens measure the polarization of the beam, they know the polarization of our beam, but we don't even know that they know that (because we can't tell if they've measure their beam or not). Secondly, once the aliens would entangle their beam with another beam, it destroys the entanglement with the original beam, which means the two things are no longer correlated. Entanglement doesn't allow you to choose the state of your system, it only allows you to know, once you've made the measurement of your side of the beam, what the other people would see if they made a measurement of the same property on their side. Nothing in entanglement (or quantum mechanics) allows instantaneous transmission of information in any way, shape, or form.

      --
      "None can love freedom heartily, but good men; the rest love not freedom, but license." --John Milton
  4. Re:Marco Ornigotti? .. immigration, collaboration? by schini · · Score: 2

    You are correct of course. Additionally, we have quite a number of italian immigrants, who came in the time of the "Wirtschaftswunder" (50s - 70s). Plus, a sizeable chunk of science in Europe is done where various institutions in different countries work together.

  5. Work-around FTL? by l0n3s0m3phr34k · · Score: 2

    I was thinking a few days ago, that perhaps the reason this might work is because the entangled pairs when moved apart are moved at non-light speeds. Therefor, even though it may NOW be transmitting at what seems FTL, the entangled system "as a whole" (including the moving apart of the entangled pair) isn't moving anything at FTL. I realize this is a total metaphysical explanation...

    1. Re:Work-around FTL? by mornfall · · Score: 2

      Saying entanglement is like teleportation is basically the same as saying that one-time pad is like PKI. With OTP, you distribute key material 'ahead of time' (just like you distribute parts of an entangled system) and then you can magically 'communicate' (securely in the case of OTP, instantaneously in case of teleportation). This all works only because you distributed things beforehand and then conveniently forgot that part. Even then, entanglement-based 'teleportation' is useless. If you forget fancy lasers and particle pairs, all you need for this kind of 'magic' is a pouch with a black and a white marble. Person A takes one out but does not look. Person B takes the pouch with the remaining marble and moves to Canada. Then A looks at his marble, discovers it is white and instantaneously knows that person B has a black one. Oooh, magic. Not.

  6. Boring: Not in violation of locality. by extensive · · Score: 5, Informative

    From the press release: "With this form of teleportation, we can, however, not bridge any given distance," admits Szameit. "On the contrary, classic teleportation only works locally." http://www.uni-jena.de/en/Rese...

  7. Relativity by Roger+W+Moore · · Score: 3, Informative

    If time is relative, then it would seem to reason that causality would have to be at best local to one's own time frame.

    Only it doesn't work like that at all in relativity: causality is preserved by the fact that information cannot travel faster than light. If you can transmit information faster than this then you can create real paradoxes which are not at all explainable i.e. events which occur in one reference frame and which do not occur in another because someone stopped them. This is not something which has ever been observed.

    My guess is that the information speed is actually less than, or equal, to that of light because we have seen this sort of thing before with tunnelling photons. A photon can tunnel through a potential barrier faster than light but the chance that it makes it is less than 100%. This means that you have to send many photons to be sure the signal is transmitted and by the time you do that the average speed of information transmission has dropped to the speed of light even though single photons are faster.

    I don't know the details of this experiment yet but I very, very strongly doubt that they actually transmit "actionable" information (i.e. information that could influence an observer's actions) at FTL speeds and I expect that the summary misread and misunderstood the results.

    1. Re:Relativity by michelcolman · · Score: 2

      They transmitted information "instantaneously" between different properties but at the same location. Nothing traveled faster than light. The part about "across multiple locations" is fiction unrelated to this experiment. They even admit that "With this form of teleportation, we can, however, not bridge any given distance".

  8. ...but it utterly breaks causality by Roger+W+Moore · · Score: 3, Informative

    Flight takes many decades, but they stay in contact with earth in realtime.

    This utterly breaks causality. For example suppose a terrorist had planted a bomb on the ship and uses this instant signal to detonate it. However nearby our hero Buzz Lightyear is cruising in the opposite direction at a large fraction of the speed of light. He sees the ship explode but in his frame of reference the terrorist of Earth has not actually pushed the button yet so he carries on flying to Earth and shoots the terrorist before the signal is sent....so why did the ship explode? ...and if it didn't explode why did Buzz fly to Earth and shoot someone?

    The moment you have FTL information transmission you have time travel: the two are inextricably linked in relativity and the moment you have time travel you have causality violations. So either this experiment does not transmit actionable information FTL or there is a serious flaw with relativity. The later would be an extraordinary claim which requires extraordinary evidence.

  9. SETI by l0n3s0m3phr34k · · Score: 2

    Tech like this would explain why SETI hasn't turned up anything. We've only been transmitting EM for around 150 years, and if this tech actually works in another 50 years this will probably be the main comms for all probes, off-world colonies, etc. In another 100, it would replace most other communication systems. That is, of course, assuming, President Trump or President Cruz don't start WWIII lol.

  10. Re:Marco Ornigotti? by PopeRatzo · · Score: 2

    Contrary to popular belief, not all Germans are known as "Guenter Gottfried" and "Friedelumurr Gieselheart"

    Yet strangely, all Swedes are named, "Sven".

    --
    You are welcome on my lawn.