back to article Quantum boffins send data ACROSS TIME AND SPACE

Researchers in Israel have pulled a trick that makes quantum physics seem even stranger than an episode of Doctor Who – they've created a pair of photons that was briefly entangled not across space, but across time. The last time El Reg discussed time-like entanglement it was being proposed as a theoretical construct. The idea …

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  1. Vladimir Plouzhnikov

    Maybe I'm wrong but

    "the researchers say, polarisation measurement on P4 showed entanglement with P1, even though P1 was destroyed before P4 was created."

    So, all it shows to me is that you can "preserve" the entanglement through intermediary agents and "conduct" it beyond the lifetime of the original pair by generating new "carriers" and transferring the original signal to them from the survivor of the first pair. Basically a polarisation transponder. It does not suggest any time travel or anything like that to me.

    1. Schultz

      ...does not suggest any time trave...

      It does some time travel, but only in the boring forward direction. Just like the rest of us.

    2. Anonymous Coward
      Anonymous Coward

      Re: Maybe I'm wrong but

      That was the first explanation in my my head, too. But I'm no QM scholar, so what do I know. But it would seem that many people would immediately jump to this 'possibility' - so shame it wasn't addressed in the article. Maybe it is in the paper but I fear I would never be able to tell.

  2. Inventor of the Marmite Laser Silver badge

    Didn't understand it first time round

    I'll wait for the repeat last week.

  3. Robert Ramsay
    Happy

    Did anyone else notice?

    Team is run by H. Eisenberg...

    1. I think so I am?
      Happy

      Re: Did anyone else notice?

      I wonder if they where smoking crystal meth at the same time they did this?

    2. quicksilver

      Re: Did anyone else notice?

      Are you certain?

    3. Michael H.F. Wilkinson Silver badge
      Joke

      Re: Did anyone else notice?

      Mr Eisenberg, are you certain you want to name your son Hagai? You realize you are dooming him to a career of quantum physics?

      1. A Nother Handle
        Paris Hilton

        Re: Did anyone else notice?

        Surely that isn't certain until he examines his degree certificate to determine which field he studied?

        1. Michael Dunn
          Joke

          Re: Did anyone else notice? @ A Nother Handle

          "Surely that isn't certain until he examines his degree certificate to determine which field he studied?"

          If he 'observes' from the degree certificate that he passed, then perhaps he didn't!

    4. David Glasgow
      Happy

      Re: Did anyone else notice?

      Good spot!

      Probably means the paper could be published just about ANYWHERE.

  4. Anonymous Coward
    Anonymous Coward

    Nothing particularly difficult about this.

    Keanu Reeves did it to Sandra Bullock, in The Lakehouse.

    Also, I left a note for my wife last night, and she read it this morning.

  5. Sander van der Wal
    FAIL

    The explanation presented here doesn't cut it

    Basically it is just stating that entanglement was measured. Which property was measured, which values the property had, and the values that the property should have is the photons were not entangled is not mentioned at all. The diagram is pointless without that information. Could as well be the number of prams sold during the year.

    1. Anonymous Coward
      Anonymous Coward

      Well it is only a summary.

      If you want that kind of detail, read the arxiv paper.

      1. Anonymous Coward
        Anonymous Coward

        Re: Well it is only a summary.

        Yeah - and a summary by a reporter, probably based largely on the press release. And even though Chirgwin actually does a very good job of his science articles, they are necessarily approximate. And, the brutal fact is, that unless you are the right type of scientist, an approximation is what you're stuck with. But there's no harm in trying to have a read of the arxiv paper anyway. Just don't blame the reporter for doing his job and trying to get the basic concepts across. If you have a disagreement with the actual work, then by all means write up a formal comment containing your technical criticisms and submit it to PRL.

  6. xeroks

    look ma, no hidden variables

    I never totally understood why these spooky action at a distance interactions couldn't be explained by simple hidden variables. I've always just gone with the flow on it. If Einstein couldn't prove it was wrong, what chance have I got.

    However, this experiment does show - without possibility of confusion - that something weird is going on, and that time is not a one way-trip.

    It also gives me a few ideas... now where's my "Hong Kong Book of Patent Applications for Things I Know Nothing About?"

    1. Paul Kinsler

      Re: I never totally understood why X couldn't be explained by simple hidden variables

      They can - if you also permit superluminal signalling. However, most physicist prefer to live with "spooky action" than with a violation of relativistic causality.

    2. Nigel 11
      IT Angle

      Re: look ma, no hidden variables

      Does superluminal signalling automatically imply time travel?

      I've read that it does. Interestingly, it's the IT angle of time travel (even if restricted to information only) which seems to me the greatest paradox. The problem is that if you can send even as little as one bit back in time, you can arrive at the result of any convergent iterative process in the time taken to compute a single iterative step (by sending the result of that iteration back in time to replace the initial approximation).

      It's only a slight stretch to claim that such a computer would inevitably transform line noise into a strongly superhuman, perhaps ultimate, intelligence. So akin to the Fermi paradox, where is IT?

      1. Paul Kinsler

        Re: Does superluminal signalling automatically imply time travel?

        To clarify - the "hidden variables" superluminal signalling is only partial; you can only extract information once you get the other part - but unfortunately that has to be sent in the ordinary way - i.e. by lightspeed limited means.

      2. Michael Wojcik Silver badge

        Re: look ma, no hidden variables

        Does superluminal signalling automatically imply time travel?

        Depends on how you define "time travel". I don't think it's a terribly useful phrase for talking about this subject.

        Superluminal signalling implies you can get an out-of-order series of signals, and acquire information about the future of your worldline. In one simple case, for example, you could send a superluminal message to a party outside your light cone (already worrisome) and get a reply back, and the reply could arrive (in your timeframe) before you sent the "original" message. That lets you send messages to yourself in the past, which either predetermines your sending the original message (because the "reply" that you already have is a response to it), or creates a paradox (because you got the reply without ever having sent the original). Either way, causality is insulted.

        If memory serves, somewhere on Wikipedia there is a set of diagrams showing how this works.

  7. Mike Brown

    love QM

    it reminds me there is more to the universe than what we can see, have seen, and will ever see

  8. david willis
    Thumb Up

    Beep

    Quantum stuff seems to get cooler every time you rea something. The concept that two quantum particals can exist at the same induced excited state seperately and over distance is the basis of many sci-fi communications systems. Now they can do this over time too. James Blish did a short story called beep, where all intersteller quantum communication ended in an annoying beep. Then somebody discovered the beep was the concatination of EVERY communication ever made using the system over ALL the time the system has, is and will be used...

  9. AJames

    Don't get too excited

    In more detailed reports the researchers made it clear that this experimental result does not in any way change the fact that quantum entanglement can not be used to transmit information faster than the speed of light or backwards in time.

    1. Michael Wojcik Silver badge

      Re: Don't get too excited

      quantum entanglement can not be used to transmit information faster than the speed of light or backwards in time

      Thank goodness. The alternative, while "exciting", would be extremely worrisome.

  10. MatsSvensson

    So it turns out the past affects not only the present, but also the future?

    I cant wait for the StarTrek episode!

  11. Dropper

    I'm wrong

    Don't bother to tell me why I'm wrong, I don't need to be confused further.. but from my perspective this is happening.

    P1 entangles with P2, transferring information and is then destroyed.

    P2 entangles with P3 and then P4.

    So you pass a letter to your neighbour, jump off a cliff and then someone is surprised when your neighbour is able to deliver your message to a person who was born after you died.

  12. David 45

    The answer to everything

    Is 42.

  13. Unicornpiss
    Alert

    How about this...

    You entangle P1 and P2, but have some automated machinery measure the state of P1 and record the result without anyone seeing it, but then continue on to base whether you entangle P2 with P3 on the result obtained from P1. You still entangle P3 with P4. What results to you get when you measure P4 and compare it with the stored measurement of P1?

    1. Mephistro
      Pint

      Re: How about this...

      " but have some automated machinery measure the state of P1 and record the result without anyone seeing it"

      One of the few things I think I got right from my Physics classes back in the day, is that it doesn't matter whether a human being knows the results of the measurement or not. The gist of QM is that any measurement of the particle's state changes said particle to an unknown state.

      A nice metaphor for this would be: You have a dark room full of marbles and the only way to know their energy/speed or position is hitting them with other marbles. But when the 'reader' marble hits a 'target' marble it changes its characteristics in an unpredictable way. Our Uni professor also said that 'classical' Physics could be derived from Quantum mechanics, as 'classical' measurements are just a compound of trillions of Quantum measures.

      Disclaimer: I'm no expert in the area, and I tend to suffer splitting headaches whenever I try to think about this for more than three minutes, so I could be catastrophically wrong.

      Mmmmhhh..., Aspirins with beer, a champion's breakfast!

  14. Martin Budden Silver badge
    FAIL

    If all this is true...

    ... we can now use a photon detector to receive messages sent to us from many years in the future. This is it! The moment that we learn everything there is to know about all technology that is developed from now until the eventual end of the human race!

    Except that it's not true, and there is no such thing as sending information back in time, and the researchers' statement "In the scenario we present here, measuring the last photon affects the physical description of the first photon in the past, before it has even been measured. Thus, the 'spooky action' is steering the system’s past" is utter bullshit.

    1. Michael Wojcik Silver badge

      Re: If all this is true...

      Try again. "[T]he 'spooky action' is steering the system’s past" can be true without there being any information transfer, whether to or from the past. Entanglement does not transfer information. Your objection is ill-founded.

  15. amanfromMars 1 Silver badge

    Your Original Wish, Our Command and Phish ........ in a SMARTR Phorm?

    So it turns out the past affects not only the present, but also the future?

    I cant wait for the StarTrek episode! … MatsSvensson Posted Monday 3rd June 2013 14:20 GMT

    Actually, it is even more fantastically simply complex than than, MatsSvensson, for with and in IT and Media Command of Information and Cyber Controlling Intelligence Centres, the past never affects the present and/or the future when aforementioned intelligence centres of excellence with Global Operating Devices mentor and monitor and advise the present that the past is materially irrevelent and bears no virtual relationship/has no physical or quantum entanglement with base imaginary fact, as historical and chronicled events in past earthly places and present spaces were and are simply fabless tales of fiction to be believed and perceived, thus creating easily changed realities …….. with words forming worlds in worlds phorming words.

    And that is also AI Universal Virtualisation with GOD ParticularIT and Quantum PeculiarIT, and Chosen Preserve and Wwwinged Reserve of the Few and Master Pilots.

    “Never in the field of human conflict was so much owed by so many to so few.”

    And IT is listening and creating your needs and feeds and seeds/wants and solutions/futures and derivative trades and zeroday vulnerabilities to exploit/export and import.

    1. MatsSvensson

      Re: Your Original Wish, Our Command and Phish ........ in a SMARTR Phorm?

      Yeah, and all over the floor too...

      1. amanfromMars 1 Silver badge

        The Existing Problem for SMARTR Phorm Competition and/or Opponents/Traditional Components

        Re: Your Original Wish, Our Command and Phish ........ in a SMARTR Phorm?

        Yeah, and all over the floor too... .... MatsSvensson Posted Tuesday 4th June 2013 04:10 GMT

        The abiding elite dilemma for both irregular and regular and conventional establishment forces, no matter how special and/or easily driven and controlled by strong human weaknesses, is that they are not accepted and their ideas are not exchanged on the trading floors of IntelAIgent CyberIntelAIgent Bourse Markets which create Virtualised Alternate Realities with Astute Active Anonymous Autonomy permitting Instant Admission to Host Events in the Great Game Field with Assumptive and Presumptive and Sumptuous Exclusive Executive Administration Rights.

  16. Robert E A Harvey

    Shock horror

    Scientists reduce the amount of stuff needed to make people go "err, right..." to 4 photons

  17. Anonymous Coward
    Anonymous Coward

    Re. Shock horror

    Maybe this explains Fermi's Paradox.

    Scenario:- civilization conquers nuclear power, develops quantum mechanical devices, invents time travel.

    Someone decides to go tinkering and KABOOOOOOOOM!

    Instant quasar.

    Turns out that time travel is possible but the Universe responds by annihilating anything within a parsec.

    AC-DC

  18. jgarbo
    Facepalm

    According to Quantum master Richard Feynman...

    "Anyone who says that they understand Quantum Mechanics does not understand Quantum Mechanics"...

  19. Vision Aforethought
    Go

    Neutrino communications

    http://visionaforethought.wordpress.com/2012/05/05/neutrino-communication-system/

  20. deedee

    In re: timewise photon entanglement

    Strikes me as very similar to Isaac Asimov's very early story (1948) "The Endochronic Properties of Resublimated Thiotimoline".

    I look forward to seeing these boffins using long chains of pre-destroyed photons to get information from the future.

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