7 ms·

I confess I haven't read the entire article, but from the abstract I was wondering, why 143 kilometers (they answer this: distance to satellites), and why those

I confess I haven't read the entire article, but from the abstract I was wondering, why 143 kilometers (they answer this: distance to satellites), and why those two islands (except to maybe show off that they were teleporting in the lap of luxury)? I'm guessing it's because there is no physical link between the two, so it will reduce skeptics' abilities to say "this is a hoax, there is a cable connecting the two stations."

ricardobeat 14y ago
But quantum teleporting does require a link between the two points. From the Wikipedia article: The prerequisites for quantum teleportation are a qubit that is to be teleported, a conventional communication channel capable of transmitting two classical bits (...) There is no teleporting in the classical meaning of the word, just communication between two locations to make a remote qubit match the (unknown) state of the local one. That state is 'teleported'.
- javert 14y ago
  There is no teleporting in the classical meaning of the word So isn't it dishonest to call it teleportation? Even if all the scientists working in this area are calling it that?
  - chc 14y ago
    No? How on earth is it dishonest to use the technical term for the thing? It doesn't seem any more dishonest than calling the constituent parts of matter "atoms" even though they can actually be split.
    - javert 14y ago
      The discovery that atoms are not atomic (could be split) came after the term was coined. On the other hand, in this case, a bunch of people decided to call something "teleportation" when it isn't teleportation.
      - chc 14y ago
        AFAIK, it is teleportation -- something is going from one place to another without having to move through the space between them -- but it just isn't what you think of when you think of "teleportation".
        rodly 14y ago
        If it is moving from A to B via some physical continuous medium, then it is not teleporting.
        tgb 14y ago
        (Note: my full qualifications are an on-going Coursera course on quantum computing that covers quantum teleportation lightly. FWIW, I recommend the course.) In vague terms, the process of quantum teleportation is the following: * You have a qubit that you want to transmit to a friend and that you don't know anything about. * create an entangled pair of qubits (such as photons) and separate them. Keep one yourself and give another to your friend. * Now you have two qubits; one entangled with your friends and one that you want to transmit. * Send your two bits through a quantum circuit (the main part being a 'controlled NOT gate'). * Your bit is now entangled with the bit that is entangled with your friends bit. * Measure each of your bits, hence 'collapsing' them. Each measurement gives you a classical bit. * Transmit your two classical bits to your friend over any classical connection. * Your friend then performs an operation on his or her qubit depending on what you send him or her. * Your friend's qubit is now in the state that your original qubit was in. Your original qubit is now in a different state. Call it teleporation if you want; it's not that unlike some sci-fi teleportation constructs of 'beaming' things places. Why bother with this? * It lets you send qubits to distant places that you have only classical channels to (and previously close enough contact share two entangled qubits). * It allows more error-resistant computations: if your qubit is difficult to construct and you wish to perform a difficult operation on it, you can actually have your friend perform the difficult operation on his or her bit - prior to teleportation - and, if it succeeds, you can then proceed with the teleportation. If it doesn't succeed, your friend may try again on another entangled qubit without messing up your difficult-to-prepare qubit. After a success and teleportation, you get the same result (up to a commutator which is usually relatively small and risk-free) as performing the difficult operation on the difficult-to-prepare qubit, but with less risk of messing it up.
    - waterlesscloud 14y ago
      Because the technical term is misleading and inaccurate. If scientists started calling walking "human teleportation" tomorrow, they'd be wrong in that too. The term "teleportation" had a very well-established meaning before they appropriated it. Scientists can make mistakes, labeling this process "teleportation" was one of those mistakes.
      - chc 14y ago
        If it was a mistake, it wasn't dishonest. If it was dishonest, they were intentionally trying to deceive people.
        marshray 14y ago
        Some of the claims people are making about the purported security advantages of quantum crypto are borderline dishonest, IMHO.
        smosher 14y ago
        Are you referring to the potential weaknesses just discovered recently?
        marshray 14y ago
        No, not specifically.
      - Cushman 14y ago
        Uh huh. Scientist: "As you can see here, we've demonstrated quantum teleportation across an unprecedented--" Journalist: "Teleportation?! Like in Star Trek?" Scientist: "Uh, no. *Quantum* teleportation is a different--" Journalist: "So you didn't send anybody through a wormhole or anything?" Scientist: "No. What we've demonstrated is the ability to--" Journalist: "It just seems like a bit of a mistake to call it 'teleportation'." Scientist: "Yes, I can see that now."
        14y ago
  - Cushman 14y ago
    Do you also get upset when biologists talk about "cloning" because they don't mean duplicating an adult like in the movies?
    - javert 14y ago
      No, because the differentia of the definition of cloning does not reference maturity (age).
  - johnpmayer 14y ago
    So Wikipedia states the following: "Quantum teleportation is unrelated to the common term teleportation – it does not transport the system itself, and does not concern rearranging particles to copy the form of an object." So, in a nutshell, scientists aren't always incredibly creative when conducting nomenclature. Although some people do find subatomic particles quite strange.
  - smosher 14y ago
    Not in any sense is it dishonest to call it quantum teleportation, since the quantum state is precisely (and only) what is subject to the phenomenon. What is dishonest is the claim that F-T-L communication is possible. The quantum state does not undergo travel during the transmission of the classical signal. The only thing that travels is the classical signal, which is needed to tell you how to read the message (and generally preserve causality in the universe.) The quantum state is teleported as though you had two objects with the selfsame quantum state. Poking one pokes the other.
    - javert 14y ago
      Teleportation is teleportation of matter. So AFAIK you can't call it quantum teleportation, for the same reason you can't call travelling along the road "road flying," i.e., flying is travelling above the ground, not on it.
      - smosher 14y ago
        The human ability to generalize concepts is amazing, watch—I'll swap out your of matter for of quantum information and suddenly you're up to speed on subject of discourse: "The teleportation of quantum information." Magic! Your language gives you away, you've already done this process in reverse to make your case, so I know you have the power to understand this concept.
        javert 14y ago
        So we can use any word to mean anything? This kind of abuse of language has serious consequences in the long run. The language of modern physics is already way too muddled. I don't understand what you're trying to say in the last sentence. But it seems like you're being derisive, which is utterly inappropriate.
  - Saavedro 14y ago
    You know, in a lot of sci-fis its not implied that teleportation is faster-than-light. Quantum teleportation does meet what does seem to be universal about "teleportation" though, which is that the "original" is necessarily destroyed. That is, it takes a thing, and moves it to another location, rather than copying it.
    - javert 14y ago
      As far as I can tell, it just replicates the state of a particle in a remote location, using another particle of the same kind. So state is being transfered (i.e., information), but not matter, and nothing is being destroyed. I might be wrong about this, but that's what someone who explained it on hn said.

ricardobeat 14y ago

But quantum teleporting does require a link between the two points. From the Wikipedia article: The prerequisites for quantum teleportation are a qubit that is to be teleported, a conventional communication channel capable of transmitting two classical bits (...) There is no teleporting in the classical meaning of the word, just communication between two locations to make a remote qubit match the (unknown) state of the local one. That state is 'teleported'.

javert 14y ago
There is no teleporting in the classical meaning of the word So isn't it dishonest to call it teleportation? Even if all the scientists working in this area are calling it that?
- chc 14y ago
  No? How on earth is it dishonest to use the technical term for the thing? It doesn't seem any more dishonest than calling the constituent parts of matter "atoms" even though they can actually be split.
  - javert 14y ago
    The discovery that atoms are not atomic (could be split) came after the term was coined. On the other hand, in this case, a bunch of people decided to call something "teleportation" when it isn't teleportation.
    - chc 14y ago
      AFAIK, it is teleportation -- something is going from one place to another without having to move through the space between them -- but it just isn't what you think of when you think of "teleportation".
      - rodly 14y ago
        If it is moving from A to B via some physical continuous medium, then it is not teleporting.
        tgb 14y ago
        (Note: my full qualifications are an on-going Coursera course on quantum computing that covers quantum teleportation lightly. FWIW, I recommend the course.) In vague terms, the process of quantum teleportation is the following: * You have a qubit that you want to transmit to a friend and that you don't know anything about. * create an entangled pair of qubits (such as photons) and separate them. Keep one yourself and give another to your friend. * Now you have two qubits; one entangled with your friends and one that you want to transmit. * Send your two bits through a quantum circuit (the main part being a 'controlled NOT gate'). * Your bit is now entangled with the bit that is entangled with your friends bit. * Measure each of your bits, hence 'collapsing' them. Each measurement gives you a classical bit. * Transmit your two classical bits to your friend over any classical connection. * Your friend then performs an operation on his or her qubit depending on what you send him or her. * Your friend's qubit is now in the state that your original qubit was in. Your original qubit is now in a different state. Call it teleporation if you want; it's not that unlike some sci-fi teleportation constructs of 'beaming' things places. Why bother with this? * It lets you send qubits to distant places that you have only classical channels to (and previously close enough contact share two entangled qubits). * It allows more error-resistant computations: if your qubit is difficult to construct and you wish to perform a difficult operation on it, you can actually have your friend perform the difficult operation on his or her bit - prior to teleportation - and, if it succeeds, you can then proceed with the teleportation. If it doesn't succeed, your friend may try again on another entangled qubit without messing up your difficult-to-prepare qubit. After a success and teleportation, you get the same result (up to a commutator which is usually relatively small and risk-free) as performing the difficult operation on the difficult-to-prepare qubit, but with less risk of messing it up.
  - waterlesscloud 14y ago
    Because the technical term is misleading and inaccurate. If scientists started calling walking "human teleportation" tomorrow, they'd be wrong in that too. The term "teleportation" had a very well-established meaning before they appropriated it. Scientists can make mistakes, labeling this process "teleportation" was one of those mistakes.
    - chc 14y ago
      If it was a mistake, it wasn't dishonest. If it was dishonest, they were intentionally trying to deceive people.
      - marshray 14y ago
        Some of the claims people are making about the purported security advantages of quantum crypto are borderline dishonest, IMHO.
        smosher 14y ago
        Are you referring to the potential weaknesses just discovered recently?
        marshray 14y ago
        No, not specifically.
    - Cushman 14y ago
      Uh huh. Scientist: "As you can see here, we've demonstrated quantum teleportation across an unprecedented--" Journalist: "Teleportation?! Like in Star Trek?" Scientist: "Uh, no. *Quantum* teleportation is a different--" Journalist: "So you didn't send anybody through a wormhole or anything?" Scientist: "No. What we've demonstrated is the ability to--" Journalist: "It just seems like a bit of a mistake to call it 'teleportation'." Scientist: "Yes, I can see that now."
      - 14y ago
- Cushman 14y ago
  Do you also get upset when biologists talk about "cloning" because they don't mean duplicating an adult like in the movies?
  - javert 14y ago
    No, because the differentia of the definition of cloning does not reference maturity (age).
- johnpmayer 14y ago
  So Wikipedia states the following: "Quantum teleportation is unrelated to the common term teleportation – it does not transport the system itself, and does not concern rearranging particles to copy the form of an object." So, in a nutshell, scientists aren't always incredibly creative when conducting nomenclature. Although some people do find subatomic particles quite strange.
- smosher 14y ago
  Not in any sense is it dishonest to call it quantum teleportation, since the quantum state is precisely (and only) what is subject to the phenomenon. What is dishonest is the claim that F-T-L communication is possible. The quantum state does not undergo travel during the transmission of the classical signal. The only thing that travels is the classical signal, which is needed to tell you how to read the message (and generally preserve causality in the universe.) The quantum state is teleported as though you had two objects with the selfsame quantum state. Poking one pokes the other.
  - javert 14y ago
    Teleportation is teleportation of matter. So AFAIK you can't call it quantum teleportation, for the same reason you can't call travelling along the road "road flying," i.e., flying is travelling above the ground, not on it.
    - smosher 14y ago
      The human ability to generalize concepts is amazing, watch—I'll swap out your of matter for of quantum information and suddenly you're up to speed on subject of discourse: "The teleportation of quantum information." Magic! Your language gives you away, you've already done this process in reverse to make your case, so I know you have the power to understand this concept.
      - javert 14y ago
        So we can use any word to mean anything? This kind of abuse of language has serious consequences in the long run. The language of modern physics is already way too muddled. I don't understand what you're trying to say in the last sentence. But it seems like you're being derisive, which is utterly inappropriate.
- Saavedro 14y ago
  You know, in a lot of sci-fis its not implied that teleportation is faster-than-light. Quantum teleportation does meet what does seem to be universal about "teleportation" though, which is that the "original" is necessarily destroyed. That is, it takes a thing, and moves it to another location, rather than copying it.
  - javert 14y ago
    As far as I can tell, it just replicates the state of a particle in a remote location, using another particle of the same kind. So state is being transfered (i.e., information), but not matter, and nothing is being destroyed. I might be wrong about this, but that's what someone who explained it on hn said.