back to article Qubits turn into time travellers

A group of scientists from Spain’s Institute of Fundamental Physics has made the world just that little bit more weird, proposing a form of quantum entanglement that spans not just space, but time. Physics followers will already be familiar with entanglement across space: two quanta (a pair of photons is a handy example) that …


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  1. AceRimmer1980

    Quantum fluctuations?

    So, you'll be needing some sort of capacitor, for quanta in flux..

  2. Thorne

    Not sure how you slow the quanta down to 88 miles per hour

  3. Bush_rat
    Paris Hilton

    Awesome! I think..

    Cool but can we communicate with the future yet? And if so, will we need to remember to communicate with ourselves from the future with out creating a paradox.

    My head hurts :(

    1. Bill Fresher

      Re: Awesome! I think..

      "Cool but can we communicate with the future yet?"

      Yes, we can send ourselves a message now and be amazed when we receive it in the future.

      1. Thorne

        Re: Awesome! I think..

        "Yes, we can send ourselves a message now and be amazed when we receive it in the future."

        We can already do that. It's called the postal service

  4. Handle This

    I would be more than willing to tell you that you've slipped up if I could get at all past the basic concept as it is described. Fascinating, but more than a little outside my field; perhaps when it's made into a comic book . . .

  5. Stephen 27

    Makes perfect sense

    So assuming the brain is in fact a quantum computer. Then this explains fortune tellers. Ahhh it all makes sense now!

    beer - medicinal purposes for strained brain

    1. AceRimmer1980

      Re: The brain is in fact a quantum computer

      Yes. Read 'Quarantine', by Greg Egan.

  6. William Boyle
    Thumb Up

    More evidence

    Just more evidence that the universe is far stranger than we can possibly imagine! My favorite physics limerick:

    There was a fellow named Bright

    Who traveled much faster than Light.

    He left one day in a relative way

    And arrived the previous night!

  7. Anonymous Coward
    Anonymous Coward


    See title.

  8. Captain DaFt

    OK... So if I'm following this right... (Note: Words and phrases in quotes are long scientific explanations boiled down to their cartoon equivalents.)

    Said physicist built a tiny virtual "doorway" and rigged it so that any photon that wandered through got "whacked on the noggin with a tiny virtual mallet".

    One wanders through, and a bit later, another followed. Then he asked them both at the same time, "How many fingers am I holding up?", and they both said, "Mommy?"... So how does this show time travel?

    1. QuinnDexter

      Love this

  9. amanfromMars 1 Silver badge

    In the Beginning, was the Empty Void a Vacuum Crowded with All Manna and Matter of Future Things.

    "Bootnote: As always, I don't mind being told I've slipped up in something as strange as this.….. Richard Chirgwin

    Quite the contrary, Richard, that was admirably surefooted.

    "After the two interactions, P and F can become entangled without ever interacting with each other – forming a correlation that’s called “past-future entanglement”.

    As the paper states, once the correlation exists, “past-future quantum correlations will have to be transferred to the qubits, even if the qubits do not coexist at the same time.”

    “Qubit F interacts with the vacuum quantum fluctuations that are correlated with the vacuum quantum fluctuations that qubit P interacted with in the past,” Sabín said. “It's like if the qubits were exchanging ‘virtual’ – as opposed to real – photons, these undetectable particles propagating faster than light that are usually employed in quantum field theory to illuminate the computations.”" ……. Would you dare care deny that is alien creationist field territory? And that which is presently collapsing proven corrupt and discredited false fields of virtual power selfishly and recklessly exercised without virtual control field command …. and seamlessly replacing them with that which is future required for AI Beta Presents …… which are in actuality, Future Product Placements in IT and Media Programs that ReProgram SMARTR Assets to Edutain with Leadership which can be Sublimely Followed via a Mass Universal Change in Consciousness which Stealthily Spontaneously Delivers Increasingly Advanced IntelAIgents Awareness of Applications in and for Qubit Entanglements in Active Crowded Vacuum Space Fields …… with a Parallel AIdDiscipline exercising HyperRadioProActive Cloud Control for Commanding Virtually Real Power Generation of Future Options and Derivative Hedges with Virtual Machine Precision Certainty for New Orderly Worlds out of Clouds Hosting Advanced Operating Systems …… Ordo ab Chao v4.2?

    ? ….. Oh yes, with Sublime IT Stealth and Immaculate Media Programming is it at least all of that, and a great deal more as will become increasingly apparent over times spent travelling in these illuminating spaces with enlightening virtual places in REST and Great IntelAIgents Games Play.

    1. jake Silver badge

      Trifle long Subject^WTitle, there, amfM (was: Re: In the Beginning, was the Empty (dot dot dot))

      Am I the only one who read "Active Crowded Vacuum Space Fields" as "Active Crowded Valium Space Fields"?

      Just askin' ...

  10. frank ly

    Practical applications ...

    When will I be able to send a message back in time to warn myself not to buy shares in Facebook?

    1. Richard 12 Silver badge

      Re: Practical applications ...

      You already will have did*.

      Such a shame you won't listened* to yourself.

      * Time travel tenses are hard.

  11. Denarius Silver badge
    Thumb Up

    so quantum computers dont need memory ?

    the qubits are entangled chronologically so when data needs to be stored or retrieved, no internal buffering required ? My head hurts also, but this seems like real physics fun.

    1. FuzzNChips

      Re: so quantum computers dont need memory ?

      Quite on the contrary, they will need lots of memory IN THE FUTURE, but since that is always "mañana", you can keep all memory as something TO BE PURCHASED... (sorry, bad pun).

  12. Destroy All Monsters Silver badge

    This is not particularly surprising

    Indeed, "single quantum systems" can very well span whatever 4-vector you choose. If Alice has one end of an entangled qubit pair, and Bob another, then relative movement between Alice and Bob will be perceived as an arbitrary difference in relative moment-of-time for faraway observers, thanks to the Special Theory of Relativity.

    Nature is powerful for keeping track of all possible connections between anything anywhere anytime down to near-infinite detail at every point in spacetime (is that still the cardinality of R?) but tries to avoid fixing herself on any actual value or as long as it can be avoided (as things get larger, it cannot be avoided).

    Informatics people, are used to the cardinality of N, try to fix things immediately (if need be by asking the user) and want throw away any detail as fast as possible. This is practically the reverse.

    1. IHateWearingATie

      Re: This is not particularly surprising

      Just put this post into Google Translate. Still don't understand.

      Isn't cardinality something to do with Porn?

      And who's N - is that Paris Hilton's pseudonym?

      1. Destroy All Monsters Silver badge

        Re: This is not particularly surprising

        Somebody else needs to explain as the servers are currently down!

    2. John G Imrie

      So the Unverse is written in Prolog

      and wants to resolve it's variables as late as possible :-)

  13. KitN

    Is this tantamount to saying tachyons are real?

    1. Destroy All Monsters Silver badge
  14. Thomas 4

    Huh, I never knew he had it in

    I'm suprised he can stop hopping up and down colour changing cubes long enough to do something as complex as time travel.

  15. Uncle Slacky Silver badge

    The makings of an ansible...

    ...or a tachyonic antitelephone, I wonder?

  16. Crisp

    Senior Management

    If they can get a quantum computer to work with this theory, then I'll finally have a way to provide senior management with those reports that they only just realised that they needed yesterday!

    1. The Original Cactus
      Thumb Up

      Re: Senior Management

      Even better than that, you can report on next week's progress and tell them to stop flapping.

  17. Yesnomaybe

    We will know when this has been perfected..

    ..when some boffin somewhere just keeps on winning the lottery.

  18. Anonymous Coward
    Anonymous Coward

    BBC Translation

    Just to re-explain this article in dumbed-down BBC News terminology...

    "Boffins in Spain were one step closer to creating a real Tardis yesterday after moving one atom to two places at the same time. The atoms were then twinned, like Chorleywood and Dardilly in France, to allow scientists to use one of the atoms as a remote control for the other. It's hoped that within five years the technology will allow the Government to eradicate youth unemployment by sending the under-25s into the future to become carers for their future selves, saving the NHS a fortune."

  19. TeeCee Gold badge


    ".....allows a time-like entanglement. In their proposed experiment...."

    Somebody stop them before they start fucking around with entanglement and cause a Resonance Cascade.

  20. Anonymous Coward

    There is an interpretation of entanglement which says that the quantum field is bollocks.

    The idea of entangled pairs is that if you measure one, the other is guaranteed to also be in that state when you measure it. There is nothing to say you have to measure them both (i.e. collapse their quantum probability field) at the same time, so in effect there is an across-time correlation already. What this is saying is that you can entangle the pair without ever bringing them together in the same place at the same time, which is clever.

    However, what is not that clever is you have no way of knowing what the outcome will be until you measure one. You can't actually force the state of a particle, or pick off a particle with a particular state, until you measure it, and then it's as good as dead. If you could force one particle to adopt a state, then measure the other, you'd at least be able to send a message. But you can't. It is neither a 'remote control' nor a 'particle telegraph'. It's simply a canny way of saying you've rolled one die and can guess the number on the other.

    So the alternate interpretation is that there is no quantum indeterminate state - the pair have been fixed all along. The dice were already rolled for you. And until you CAN influence the state of one (and thus the other) there's not much point in having any other interpretation as it doesn't actually do you any good.

    1. <a|a>=1

      Re: There is an interpretation of entanglement which says that the quantum field is bollocks.

      Why can one not prepare the state of one of the pair, for example by aligning it in an electric field?

      1. Anonymous Coward
        Anonymous Coward

        Re: Why can one not prepare the state of one of the pair..?

        First off there is a lot of jingoism surrounding quantum theory, like any techy field. Any sort of interaction with the particle such as you're suggesting - anything that could have a knock-on effect on anything else in the universe - will count as an 'observation'. And observing is 'GAME OVER' as far as quantum states are concerned. Once it's been 'observed' it is no longer entangled. So really they're only entangled whilst both of them are in an unknown state. Which is a novelty, certainly, but useful? Not so far. At least not until someone else has a very bright idea. Or invents the 'Heisenberg Compensator'.

    2. Martin Budden Silver badge

      Re: There is an interpretation of entanglement which says that the quantum field is bollocks.

      I have a pair of those, and there isn't any entanglement because I shower every morning.

  21. Jason Hindle

    Really quite confused.....

    Does this mean information could be encoded and sent backwards in time using a quantum computer thingy?

    1. Anonymous Coward
      Anonymous Coward

      Re: Really quite confused.....

      Not until someone invents a way of forcing a known state onto a particle without actually knowing what state that is - which is as contradictory as it sounds whatever level of interpretation you would like to apply. You need to know you've done it but it has to be an unknown known for the other end to only become a known known when you measure it. Actually, I'm sure Donald Rumsfeld could explain it better...

  22. Mikey

    Time travelling entangled particles, eh?

    You know, I've got the strangest feeling I've read this before...

  23. Adam T

    Proven already.

    I experience this phenomena all the time when arguing with the wife.

    Consider, arguing over a map while trying to get somewhere. She's accusing me of giving her the wrong directions, and I'm arguing a point that I am in fact correct. She refuses to see my point, thus the Point is unobserved.

    Only later, when I'm proven correct by a situation which was YET TO HAPPEN does she see (and so Observe) my point. In this case, the point existed both half an hour ago, and half an hour later: it's the same point, but she sees it in a different point-in-time.

    Thus I propose that arguments with the wife are in fact evidence of past-future-entanglement.

  24. Trollslayer
    Thumb Up

    "As always, I don't mind being told I've slipped up in something as strange as this."

    Now THAT is the scientific method, thank you.

    We live in interresting times but multi time grammar is goign to get a bit convoluted!

    1. Chemist

      Re: "As always, I don't mind being told I've slipped up in something as strange as this."

      "multi time grammar is goign to get a bit convoluted"

      Suggest you read the relevant section of the HHGG

  25. Anonymous Coward
    Anonymous Coward


    All they've done is proposed entangling two particles via an intermediary. It says nothing about whether the entangled particles reveal their correlation at different points in time - that is always possible, as you can choose when you measure each of them.

    Time travel? No.

  26. Anonymous Coward
    Anonymous Coward

    Temporally entangled photons

    Not so far fetched, however it would raise significant problems for causality.

    However for reasonable energy densities (ie other than hypernovae/black hole merges/etc) the effect would likely be indistinguishable from background noise.

    I wonder if this effect can be used to detect a star about to go supernova shortly before it does, by detecting the entangled particle wavefront?

  27. cortland

    Holy homeopathic tachyons!

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