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Quantum communication requires a continually renewed source of mutually shared entangled pairs to send communication. When entangled states collapse, which they

Quantum communication requires a continually renewed source of mutually shared entangled pairs to send communication. When entangled states collapse, which they must do in order to send information, the particle pairs are no longer entangled and can thus no longer send information. These civilizations would have to find a way to keep a stable quantum pairing which can be observed without collapsing the quantum state, which is the equivalent of finding a way to stop black holes from emitting Hawking radiation; essentially they would need to find a way to stop entropy as we know it in order to make long distance quantum communication sustainable.

mrfusion 5y ago
Place a beam splitter between you and fire a laser. Get entangled particles back. Or place an entangled particle emitter between you
trutannus 5y ago
> These advanced civilizations would require technology I can't think of how to implement I mean, that's part of what makes them advanced civilizations.
- suifbwish 5y ago
  Advancements in technology will probably not do away with what we already understand about physics, it will likely just add more details.
  - trutannus 5y ago
    >Advancements in technology will probably not do away with what we already understand about physics, it will likely just add more details Could have been said in the 1800's about why we'd never have quantum computers.
Moodles 5y ago
Is it really "equivalent"? I get both problems are about entropy in the universe but I would have thought managing the state of a black is harder, due to its suction into oblivion and whatnot. I don't know much about if it's possible to make entangled particles stable somehow, or whether you could maybe just have a lot of them so you never run out even if a lot become untangled naturally. Doesn't quantum key exchange use entangled particles? So it must be possible to keep them stable for at least a little while.
throw1234651234 5y ago
I don't get it - wasn't it concluded that instantaneous communication is impossible, aka you can't transmit information EVEN if you were to take a decade to move two entangled particles apart, all you would get is data from 10 years ago?
- grepfru_it 5y ago
  FTL communication is not possible. You have access to the entangled particle right now but, to send information, you are bound to the limits of the classical channel (the 10 year problem transmitting information about the entanglement)
  - fasdf23qwe 5y ago
    This would be correct if causality is an absolut certainty in all the universe, the whole time, but what if causality it actually isn't a certainty in some contexts? Tadah..you would get ala "FTL" comms enabled.
    - drdeca 5y ago
      Isn’t this just saying that if you could send a signal faster than c, then you could send a signal faster than c? I don’t see your point.
      - fasdf23qwe 5y ago
        Sorry, I didn't wanted to write it like that was psychosis somehow. I meant, causality as I understand, it could be not a fully understood concept. We could still find evidence - in the future - that there are phenomena capable of "evade" the cause-effect principle. https://en.wikipedia.org/wiki/Faster-than-light_neutrino_anomaly https://en.wikipedia.org/wiki/Faster-than-light_neutrino_ano...
      - fasdf23qwe 5y ago
        To add more speculation, the idea from the movie "Tenet" could be a way to effectively surpase C in long distance communications: reversed entropy matter. You could just send a ship or some kind of vesel with reversed entropy to a star and it will arrive years later, but years sooner that it was launched. Matter is more or less energy, what if this trick could be done with reversed entropy energy: radio, x-rays, gamma rays, etc.

mrfusion 5y ago

Place a beam splitter between you and fire a laser. Get entangled particles back. Or place an entangled particle emitter between you

trutannus 5y ago

> These advanced civilizations would require technology I can't think of how to implement I mean, that's part of what makes them advanced civilizations.

suifbwish 5y ago
Advancements in technology will probably not do away with what we already understand about physics, it will likely just add more details.
- trutannus 5y ago
  >Advancements in technology will probably not do away with what we already understand about physics, it will likely just add more details Could have been said in the 1800's about why we'd never have quantum computers.

Moodles 5y ago

Is it really "equivalent"? I get both problems are about entropy in the universe but I would have thought managing the state of a black is harder, due to its suction into oblivion and whatnot. I don't know much about if it's possible to make entangled particles stable somehow, or whether you could maybe just have a lot of them so you never run out even if a lot become untangled naturally. Doesn't quantum key exchange use entangled particles? So it must be possible to keep them stable for at least a little while.

throw1234651234 5y ago

I don't get it - wasn't it concluded that instantaneous communication is impossible, aka you can't transmit information EVEN if you were to take a decade to move two entangled particles apart, all you would get is data from 10 years ago?

grepfru_it 5y ago
FTL communication is not possible. You have access to the entangled particle right now but, to send information, you are bound to the limits of the classical channel (the 10 year problem transmitting information about the entanglement)
- fasdf23qwe 5y ago
  This would be correct if causality is an absolut certainty in all the universe, the whole time, but what if causality it actually isn't a certainty in some contexts? Tadah..you would get ala "FTL" comms enabled.
  - drdeca 5y ago
    Isn’t this just saying that if you could send a signal faster than c, then you could send a signal faster than c? I don’t see your point.
    - fasdf23qwe 5y ago
      Sorry, I didn't wanted to write it like that was psychosis somehow. I meant, causality as I understand, it could be not a fully understood concept. We could still find evidence - in the future - that there are phenomena capable of "evade" the cause-effect principle. https://en.wikipedia.org/wiki/Faster-than-light_neutrino_anomaly https://en.wikipedia.org/wiki/Faster-than-light_neutrino_ano...
    - fasdf23qwe 5y ago
      To add more speculation, the idea from the movie "Tenet" could be a way to effectively surpase C in long distance communications: reversed entropy matter. You could just send a ship or some kind of vesel with reversed entropy to a star and it will arrive years later, but years sooner that it was launched. Matter is more or less energy, what if this trick could be done with reversed entropy energy: radio, x-rays, gamma rays, etc.