6 ms·

"Entanglement forms the link that will provide a future quantum internet" -- gee, if it was hard to explain to people that entanglement doesn't break the speed

"Entanglement forms the link that will provide a future quantum internet" -- gee, if it was hard to explain to people that entanglement doesn't break the speed limit by transmitting information instantaneously before.. yeah we're going to need a simple go-to explanation of what this actually is and how it works.

dash2 8y ago
Please provide a brief one, or a few links! I'd love to know.
- marcosdumay 8y ago
  You can't choose what is the value you read from an entangled particle, thus you can't choose what value your peer reads either. Your peer will read the inverse value that you read, but that alone does not make any information go through the channel.
  - tgb 8y ago
    Oh it's better than that! The term "quantum teleportation" is horribly misleading but that would be a major application of this. What "quantum teleportation" should maybe be thought of is allowing you transmit a quantum bit to someone else by instead (A) sharing an entangled particle pair ahead of time and (B) transmitting two (non-quantum) bits to them over, say, ethernet. If you prepare your half of the entagled particle pair properly and send them the right two (classical) bits, then they will be able to reconstruct your original quantum bit out of their entangled particle. So it's a way of getting my quantum bit to your quantum computer without having to pick it up and move it over there. It doesn't happen faster than the speed of light since it still involves transferring 2 regular bits. And it's not really teleportation, unless I "teleport" an image to you by sending emailing it to you. The main difference with sending regular bits is that you inherently destroy your original quantum bit before you "teleport" it, which is presumably where the name comes from. Since copying quantum bits is impossible (the "no-clone theorem"), you can't work around that destruction either.
    - jfoutz 8y ago
      I know, like, nothing about this. But my wiki reading makes me think this is essentially a one time pad. you share the entangled bits, you send a message, the message tells you what to do if your entangled bit is one, or zero. nobody can mess with the entangled bits, or they lose entanglement, and the message becomes random. i dunno, it seems like if you had a bunch of them you could make a secure channel.
      - marcosdumay 8y ago
        > i dunno, it seems like if you had a bunch of them you could make a secure channel. I don't think anybody solved man in the middle attacks against it yet. If the attacker takes hold of both the entangled channel and the classical channel, he can impersonate both parties and keep the conversation going. And you can't store those pairs. All those articles are about people that made them survive long enough for transmission. So you can't distribute them in person.
        AlexCoventry 8y ago
        That MITM attack is considerably more fragile than just reading a one-time pad during transit, though.
        marcosdumay 8y ago
        Asymmetric encryption is cheaper, survives storage, requires only the transmission of public data, and is not fundamentally flawed like that. It is also more versatile.
        akvadrako 8y ago
        But non-quantum encryption hasn't been mathematically proven to be secure. In the real world, you'll probably always use both and only if large quantum computers become available.
  - cube2222 8y ago
    Could you please elaborate? If I understand correctly what is written here, observingicle causes it to increase its, and its peers, state. Wouldn't this let you to decide afterwards if you wanted to again observe it and invert the state if you wanted? Or does observing break entanglement / an inverted particle doesn't get inverted back after another observation?
    - ianai 8y ago
      Entanglement is broken on observation. “Mike and Ike” suggest we may have a “department of entanglement“ someday like we have a DOE. It’s a scarce resource. About the best application I’ve read so far is using entanglement as a signal amplifier (my over simplification).
  - flatline 8y ago
    But if you have n entanglements you can get n bits of information from the channel by timing the disentanglements at agreed-upon intervals, no? Like, Morse code...
    - marcosdumay 8y ago
      You can't observe the entanglement breaking. You can only observe the particle's state.
IanCal 8y ago
Typically (thinking back to uni days) these things are done more for the (statistical) guarantee that nobody has peeked at what's going down the wire. Though I expect changes like this are probably more broadly applicable.
hannob 8y ago
Here's your simple go-to explanation: The quantum internet is a buzzword to extract research money from EU programs. It has no relevance whatsoever for the real internet.
- raverbashing 8y ago
  Or, more generically, whenever adding for government grants, use the buzzwords of the day Today it could be block chain, yesterday it was telemedicine, etc
- consp 8y ago
  Considering the article is from the press office it is full of buzzword bingo words and meant to be that way. The real article (haven't found a preprint yet) should be far more scientific and worthy of notice. The 'internet' won't benefit directly, today, but might somehow in the future. As with all fundamental research: we don't know yet. Let's not be judgemental beforehand.
- Faaak 8y ago
  Wouldn't light-speed internet be useful ? I would think that HFT firms would be interested in them
  - coldtea 8y ago
    We already have "light-speed internet" or close enough. Signals in cables travel at (approximately) light speed (for the medium, which is not vacuum). And we do have wireless EM signals and fiber optics cables as well...
    - Faaak 8y ago
      The velocity factor is around 2/3 in optical fiber. That's slow to HFT firms. For example, the delay compared to vacuum/c would be of of 2ms for a 1000km link. And that does not take into account fiber repeaters or microwave links
      - 8y ago
vertexFarm 8y ago
Yeah, what the hell happened to the no-communication theorem? I'm guessing bad science journalism inserted this quanternet idea in a fit of zeal? If it does happen and it gets named The Quanternet, I want some credit by the way. Y'all heard it here first.
krapp 8y ago
>If it was hard to explain to people that entanglement doesn't break the speed limit by transmitting information instantaneously before.. Blame whomever came up with the term "quantum teleportation" for what should probably more correctly be called "quantum transmission."

dash2 8y ago

Please provide a brief one, or a few links! I'd love to know.

marcosdumay 8y ago
You can't choose what is the value you read from an entangled particle, thus you can't choose what value your peer reads either. Your peer will read the inverse value that you read, but that alone does not make any information go through the channel.
- tgb 8y ago
  Oh it's better than that! The term "quantum teleportation" is horribly misleading but that would be a major application of this. What "quantum teleportation" should maybe be thought of is allowing you transmit a quantum bit to someone else by instead (A) sharing an entangled particle pair ahead of time and (B) transmitting two (non-quantum) bits to them over, say, ethernet. If you prepare your half of the entagled particle pair properly and send them the right two (classical) bits, then they will be able to reconstruct your original quantum bit out of their entangled particle. So it's a way of getting my quantum bit to your quantum computer without having to pick it up and move it over there. It doesn't happen faster than the speed of light since it still involves transferring 2 regular bits. And it's not really teleportation, unless I "teleport" an image to you by sending emailing it to you. The main difference with sending regular bits is that you inherently destroy your original quantum bit before you "teleport" it, which is presumably where the name comes from. Since copying quantum bits is impossible (the "no-clone theorem"), you can't work around that destruction either.
  - jfoutz 8y ago
    I know, like, nothing about this. But my wiki reading makes me think this is essentially a one time pad. you share the entangled bits, you send a message, the message tells you what to do if your entangled bit is one, or zero. nobody can mess with the entangled bits, or they lose entanglement, and the message becomes random. i dunno, it seems like if you had a bunch of them you could make a secure channel.
    - marcosdumay 8y ago
      > i dunno, it seems like if you had a bunch of them you could make a secure channel. I don't think anybody solved man in the middle attacks against it yet. If the attacker takes hold of both the entangled channel and the classical channel, he can impersonate both parties and keep the conversation going. And you can't store those pairs. All those articles are about people that made them survive long enough for transmission. So you can't distribute them in person.
      - AlexCoventry 8y ago
        That MITM attack is considerably more fragile than just reading a one-time pad during transit, though.
        marcosdumay 8y ago
        Asymmetric encryption is cheaper, survives storage, requires only the transmission of public data, and is not fundamentally flawed like that. It is also more versatile.
        akvadrako 8y ago
        But non-quantum encryption hasn't been mathematically proven to be secure. In the real world, you'll probably always use both and only if large quantum computers become available.
- cube2222 8y ago
  Could you please elaborate? If I understand correctly what is written here, observingicle causes it to increase its, and its peers, state. Wouldn't this let you to decide afterwards if you wanted to again observe it and invert the state if you wanted? Or does observing break entanglement / an inverted particle doesn't get inverted back after another observation?
  - ianai 8y ago
    Entanglement is broken on observation. “Mike and Ike” suggest we may have a “department of entanglement“ someday like we have a DOE. It’s a scarce resource. About the best application I’ve read so far is using entanglement as a signal amplifier (my over simplification).
- flatline 8y ago
  But if you have n entanglements you can get n bits of information from the channel by timing the disentanglements at agreed-upon intervals, no? Like, Morse code...
  - marcosdumay 8y ago
    You can't observe the entanglement breaking. You can only observe the particle's state.

IanCal 8y ago

Typically (thinking back to uni days) these things are done more for the (statistical) guarantee that nobody has peeked at what's going down the wire. Though I expect changes like this are probably more broadly applicable.

hannob 8y ago

Here's your simple go-to explanation: The quantum internet is a buzzword to extract research money from EU programs. It has no relevance whatsoever for the real internet.

raverbashing 8y ago
Or, more generically, whenever adding for government grants, use the buzzwords of the day Today it could be block chain, yesterday it was telemedicine, etc
consp 8y ago
Considering the article is from the press office it is full of buzzword bingo words and meant to be that way. The real article (haven't found a preprint yet) should be far more scientific and worthy of notice. The 'internet' won't benefit directly, today, but might somehow in the future. As with all fundamental research: we don't know yet. Let's not be judgemental beforehand.
Faaak 8y ago
Wouldn't light-speed internet be useful ? I would think that HFT firms would be interested in them
- coldtea 8y ago
  We already have "light-speed internet" or close enough. Signals in cables travel at (approximately) light speed (for the medium, which is not vacuum). And we do have wireless EM signals and fiber optics cables as well...
  - Faaak 8y ago
    The velocity factor is around 2/3 in optical fiber. That's slow to HFT firms. For example, the delay compared to vacuum/c would be of of 2ms for a 1000km link. And that does not take into account fiber repeaters or microwave links
    - 8y ago

vertexFarm 8y ago

Yeah, what the hell happened to the no-communication theorem? I'm guessing bad science journalism inserted this quanternet idea in a fit of zeal? If it does happen and it gets named The Quanternet, I want some credit by the way. Y'all heard it here first.

krapp 8y ago

>If it was hard to explain to people that entanglement doesn't break the speed limit by transmitting information instantaneously before.. Blame whomever came up with the term "quantum teleportation" for what should probably more correctly be called "quantum transmission."