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Communications Encryption Technology

Instant Quantum Communication Is Near 287

fljmayer writes "In this experiment, researchers in Australia and Japan were able to transfer quantum information from one place to another without having to physically move it. It was destroyed in one place and instantly resurrected in another, 'alive' again and unchanged. This is a major advance, as previous teleportation experiments were either very slow or caused some information to be lost."
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Instant Quantum Communication Is Near

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  • Re:Physics (Score:5, Interesting)

    by TexVex ( 669445 ) on Tuesday April 19, 2011 @09:06PM (#35875926)

    The actual spookiness is in the details, like what if I now measure it's spin with respect to a different axis, the classical and quantum results differ then, but I cannot think of any practical application this provides us.

    Basically, the rate of correlation when measuring entangled things is a function of the orientations of the detectors. The only way to explain that is: 1> Assume that the universe is deterministic, so the entire future state of the system is known at the time of the event that creates the entanglement; 2> Assume that a change made to one member of an entangled pair have an instant effect across any distance on the other member of that pair.

    Since entanglement and randomness are inextricably linked here, there's no way to use the effect to either foresee the future or communicate faster than light (and by extension, change the past). So you're right that there's no practical application for it.

    It just raises some extremely thought-provoking questions about the nature of our reality.

  • Re:Physics (Score:5, Interesting)

    by bill_mcgonigle ( 4333 ) * on Tuesday April 19, 2011 @09:18PM (#35875998) Homepage Journal

    Physicists will say, how could the other electron possibly know this, instantly

    Why would they assume that the electrons are separated? Because we perceive them that way?

    Isn't it easier to assume that they're not separate entities and that we just don't know how the universe is put together than to assume that we understand the universe and there's a 'magical' force communicating across infinite distance?

  • Re:Physics (Score:5, Interesting)

    by iris-n ( 1276146 ) on Wednesday April 20, 2011 @12:44AM (#35877148)

    It's not really quite clear what the breakthrough is here. But I'm fairly certain it doesn't involve a group velocity (i.e. information transmission) greater than c.

    You're right, it isn't. This article makes me sick. If people take shit like this seriously they can't be blamed for not being able to differentiate real science from quantum woo [rationalwiki.org].

    It's better to just ignore than try to correct it.

    Teleportation [wikipedia.org] is a real phenomenon, albeit a bit old. This is not their breakthrough. The breakthrough is doing it with a cat state (the name is a reference to Schrödinger's cat; this kind of state was inspired in it). These states are usually very fragile, and strongly entangled, hence the interest.

    Also other breakthrough is doing it with the measurement of the number of photons and position. This is a promising technique, that I am personally working with at the moment to test Bell inequalities, because of its high resistance to noise. But I don't think it is very exciting to the general public...

Math is like love -- a simple idea but it can get complicated. -- R. Drabek

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