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A question I always had is wouldn't all sufficiently advanced civs use quantum communication which we wouldn't be able to detect with our usual SETI-style metho

A question I always had is wouldn't all sufficiently advanced civs use quantum communication which we wouldn't be able to detect with our usual SETI-style methods?

lokimedes 5y ago
Quantum or not, any type of propagating and interacting particle or force can be used for communication. We primarily rely on electromagnetism but neutrinos, gravitational waves, charged or neutral particle beams etc. could be used as well. All of them have unique states that can be used to encode information. Spin, charge, neutrino flavor phases, etc. As for entangled pairs, which I presume you imply by quantum communication, it really isn’t a hidden dimension with magical properties of superluminal communication, it just implies that two particles can have shared/correlated quantum states (assuming you can keep coherence). The coherence requirement basically means that the longer a particle is exposed to the normal world, the bigger the chances of some kind of stray interaction with other particles or forces, that will break entanglement. Further, for using this for anything, we’ll need to store the local particle for the duration of flight of the emitted one. That is also a technical problem of some magnitude if the distances are light years. The short answer is that we don’t even come near to monitoring all “propagators” let alone all possible encoding schemes for these, for SETI.
behnamoh 5y ago
Probably, but before getting to that stage, they most likely used similar EM waves to transmit signals. We must be able to detect at least some of that radiation, but still nothing. The galaxy is insanely quiet, which worries me. On the other hand, it could be that they advanced to the age of using EM waves not too long ago, which means their signals are still on the way and we'll probably detect those in the future.
- jjulius 5y ago
  >The galaxy is insanely quiet, which worries me. Genuinely curious - why does that worry you?
  - monkeycantype 5y ago
    Maybe there’s a better place with no entropy just a portal away
  - crystalmeph 5y ago
    I’m not the poster you’re asking this of, but the reasons why a seemingly empty universe are concerning basically all boil down to “it indicates that the universe is hostile to civilization specifically, or to life in general.” If the universe is neutral or friendly to civilizations, then we should expect to find someone out there in fairly short order. The universe is so large, even if there’s only a one in several billion chance of a particular solar system birthing a civilization, there should be a few others besides us already in the Milky Way. If there’s not anyone else, the best case is that we are simply the first (this is my personal bet). Worse scenarios include civilizations simply fail and die after some time, or that one “predator” civilization kills off any other civilizations it finds before they can become a threat.
    - gpt5 5y ago
      > the best case is that we are simply the first (this is my personal bet) This would be odd given that 95% of the stars to ever be created in our universe have already been made. https://nautil.us/issue/104/harmony/the-universe-already-made-almost-all-the-stars-it-will-ever-make https://nautil.us/issue/104/harmony/the-universe-already-mad...
  - behnamoh 5y ago
    As Arthur C. Clark said: Either we're alone or we're not. Both are equally scary. To think that with billions of stars, each with at least one planet, intelligent life only happened on one planet (the Earth) means intelligent life is super rare, even if life in general happens on many planets. This means if we get hit by an asteroid or don't get passed the Great Filter, the only ones who "think" about this universe and give a meaning to it will be gone forever.
    - WalterBright 5y ago
- ofTheFountain 5y ago
  It's less that the galaxy is quite that's disturbing, as like you said it's possible EM based communication is only used for a relatively short amount t of time. The fact that the universe seems to be totally natural, without any intelligent interference is more concerning. No megastructures or evidence that our solar system has been visited.
jasonlaramburu 5y ago
As far as we know, information cannot be transmitted faster than light, even between two entangled quantum particles. https://www.forbes.com/sites/chadorzel/2016/05/04/the-real-reasons-quantum-entanglement-doesnt-allow-faster-than-light-communication/?sh=1ca793b73a1e https://www.forbes.com/sites/chadorzel/2016/05/04/the-real-r...
- hulitu 5y ago
  As far as _we_ know. Till some time ago we did not knew about relativity. P.S. It's really funny to see forbes as a source of science.
  - simonh 5y ago
    If we’re going to seriously discuss things we don’t know, and have reasons to believe aren’t possible, where are the boundaries? What if advanced civilisations asked fairies to take the messages for them?
    - madflame991 5y ago
      I'm always a bit skeptical about physics because whatever models we find and celebrate now will have to be adjusted at some point in the future. I wonder if there's any way of knowing that something is indeed impossible or if our model of something is final and set in stone. I'm happy there are at least some universal constants like absolute zero or the max possible temp or planck length. And as for anything FTL, I hear it breaks the rules of causality and that seems to be a big no-no and is indeed impossible.
      - he0001 5y ago
        > I'm always a bit skeptical about physics because whatever models we find and celebrate now will have to be adjusted at some point in the future. Do you have an alternative?
      - simonh 5y ago
        >I'm always a bit skeptical about physics because whatever models we find and celebrate now will have to be adjusted at some point in the future... The physics we have at any given time is tested through experimentation, and has proven effective and accurate to some degree. Within those parameters it's verified. So skepticism of current physics makes sense to a point, we know it's not complete, but we also know that in a massive range of many complex and sophisticated tests it turns out to be precisely accurate. That's got to count for something. Testability is a strength not a weakness, it means we know for sure what the limits of our understanding are. Outside the domain of science we have no such heuristic, so we have no idea whether or to what extent anything we think up bears any relation to reality whatsoever.
wumpus 5y ago
What is "quantum communication"? So far the only quantum communication we've done over distance is via photons, which are still photons.

A question I always had is wouldn't all sufficiently advanced civs use quantum communication which we wouldn't be able to detect with our usual SETI-style methods?

lokimedes 5y ago

Quantum or not, any type of propagating and interacting particle or force can be used for communication. We primarily rely on electromagnetism but neutrinos, gravitational waves, charged or neutral particle beams etc. could be used as well. All of them have unique states that can be used to encode information. Spin, charge, neutrino flavor phases, etc. As for entangled pairs, which I presume you imply by quantum communication, it really isn’t a hidden dimension with magical properties of superluminal communication, it just implies that two particles can have shared/correlated quantum states (assuming you can keep coherence). The coherence requirement basically means that the longer a particle is exposed to the normal world, the bigger the chances of some kind of stray interaction with other particles or forces, that will break entanglement. Further, for using this for anything, we’ll need to store the local particle for the duration of flight of the emitted one. That is also a technical problem of some magnitude if the distances are light years. The short answer is that we don’t even come near to monitoring all “propagators” let alone all possible encoding schemes for these, for SETI.

behnamoh 5y ago

Probably, but before getting to that stage, they most likely used similar EM waves to transmit signals. We must be able to detect at least some of that radiation, but still nothing. The galaxy is insanely quiet, which worries me. On the other hand, it could be that they advanced to the age of using EM waves not too long ago, which means their signals are still on the way and we'll probably detect those in the future.

jjulius 5y ago
>The galaxy is insanely quiet, which worries me. Genuinely curious - why does that worry you?
- monkeycantype 5y ago
  Maybe there’s a better place with no entropy just a portal away
- crystalmeph 5y ago
  I’m not the poster you’re asking this of, but the reasons why a seemingly empty universe are concerning basically all boil down to “it indicates that the universe is hostile to civilization specifically, or to life in general.” If the universe is neutral or friendly to civilizations, then we should expect to find someone out there in fairly short order. The universe is so large, even if there’s only a one in several billion chance of a particular solar system birthing a civilization, there should be a few others besides us already in the Milky Way. If there’s not anyone else, the best case is that we are simply the first (this is my personal bet). Worse scenarios include civilizations simply fail and die after some time, or that one “predator” civilization kills off any other civilizations it finds before they can become a threat.
  - gpt5 5y ago
    > the best case is that we are simply the first (this is my personal bet) This would be odd given that 95% of the stars to ever be created in our universe have already been made. https://nautil.us/issue/104/harmony/the-universe-already-made-almost-all-the-stars-it-will-ever-make https://nautil.us/issue/104/harmony/the-universe-already-mad...
- behnamoh 5y ago
  As Arthur C. Clark said: Either we're alone or we're not. Both are equally scary. To think that with billions of stars, each with at least one planet, intelligent life only happened on one planet (the Earth) means intelligent life is super rare, even if life in general happens on many planets. This means if we get hit by an asteroid or don't get passed the Great Filter, the only ones who "think" about this universe and give a meaning to it will be gone forever.
  - WalterBright 5y ago
ofTheFountain 5y ago
It's less that the galaxy is quite that's disturbing, as like you said it's possible EM based communication is only used for a relatively short amount t of time. The fact that the universe seems to be totally natural, without any intelligent interference is more concerning. No megastructures or evidence that our solar system has been visited.

jasonlaramburu 5y ago

As far as we know, information cannot be transmitted faster than light, even between two entangled quantum particles. https://www.forbes.com/sites/chadorzel/2016/05/04/the-real-reasons-quantum-entanglement-doesnt-allow-faster-than-light-communication/?sh=1ca793b73a1e https://www.forbes.com/sites/chadorzel/2016/05/04/the-real-r...

hulitu 5y ago
As far as _we_ know. Till some time ago we did not knew about relativity. P.S. It's really funny to see forbes as a source of science.
- simonh 5y ago
  If we’re going to seriously discuss things we don’t know, and have reasons to believe aren’t possible, where are the boundaries? What if advanced civilisations asked fairies to take the messages for them?
  - madflame991 5y ago
    I'm always a bit skeptical about physics because whatever models we find and celebrate now will have to be adjusted at some point in the future. I wonder if there's any way of knowing that something is indeed impossible or if our model of something is final and set in stone. I'm happy there are at least some universal constants like absolute zero or the max possible temp or planck length. And as for anything FTL, I hear it breaks the rules of causality and that seems to be a big no-no and is indeed impossible.
    - he0001 5y ago
      > I'm always a bit skeptical about physics because whatever models we find and celebrate now will have to be adjusted at some point in the future. Do you have an alternative?
    - simonh 5y ago
      >I'm always a bit skeptical about physics because whatever models we find and celebrate now will have to be adjusted at some point in the future... The physics we have at any given time is tested through experimentation, and has proven effective and accurate to some degree. Within those parameters it's verified. So skepticism of current physics makes sense to a point, we know it's not complete, but we also know that in a massive range of many complex and sophisticated tests it turns out to be precisely accurate. That's got to count for something. Testability is a strength not a weakness, it means we know for sure what the limits of our understanding are. Outside the domain of science we have no such heuristic, so we have no idea whether or to what extent anything we think up bears any relation to reality whatsoever.

wumpus 5y ago

What is "quantum communication"? So far the only quantum communication we've done over distance is via photons, which are still photons.