10 ms·

I somehow feel like quantum computing will forever remain a theory and never make it into practice. How much reason is there to believe that I might be wrong?

e19293001 9y ago
Very long time ago, talking to a person in real time 1000 miles away from you had been considered impossible.
- throwaway613834 9y ago
  Sure, but even more recently than that, it was imagined we'd be in flying cars by now, but we aren't. That's not really an argument.
  - remline 9y ago
    Flying cars not existing has everything to do with the resources they use (public federally controlled airspace which requires every driver to be a pilot.) Quantum computers have the same barriers as other private space technology. The question to me is how long they will take to go from research toys to hobby toys which has a lot to do with cost and something to do with consumer safety.
    - throwaway613834 9y ago
      Actually I mentioned flying cars due to fuel inefficiency (I automatically assumed it was too low to make them practical) but I neglected to actually check their energy usage, and now that I just did it seems like the maximum efficiency could be on par with a normal car and it would depend on the actual trip, so my mistake on that. A better example might be artificial intelligence and the AI winters. Like the failure of machine translation despite high hopes in the 1960s. It took us some 50 years to get to where we are now with Google Translate, and it still only works well for some languages. I have no idea how close to human accuracy it will get, so I would neither be surprised if it never does, nor if it does someday. Anyway, hopefully instead of picking on the particular examples you can see that my point is obviously that people imagined we'd have a lot of things now that we still don't have the technology for today. So the fact that we've done amazing things in certain areas doesn't really say anything regarding this particular issue.
      - remline 9y ago
        I see your point. I'm just trying to point out that failures of general tech to emerge are quite different than failures of use cases. You need more of a limit preventing the emergence of a Moore's law on entanglements to really make quantum computing go away and not just solve other problems than those originally assumed to be "easy" and months away.
      - jamesrcole 9y ago
        > my point is obviously that people imagined we'd have a lot of things now that we still don't have the technology for today. So the fact that we've done amazing things in certain areas doesn't really say anything regarding this particular issue. And there's plenty of things that people said were impossible that were achieved. That doesn't tell us anything regarding quantum computing, either. Looking at what people said about past things is completely irrelevant to the prospects for some particular potential technology. The only way you can try to judge the prospects for that technology is by actually getting into the details of that technology and how it relates to our current understanding of the world.
        throwaway613834 9y ago
        > And there's plenty of things that people said were impossible that were achieved. That doesn't tell us anything regarding quantum computing, either. Exactly. That was never my reasoning either so I'm not sure what you're refuting.
        jamesrcole 9y ago
        I'm not refuting anything. All your comments have focused on things that people have promised that haven't turned out, which gives one the impression that that somehow applies to quantum computing as well. I'm trying to paint a more balanced picture of the situation.
  - aaron695 9y ago
    Flying cars have existed for 100 years. What you seem to be asking is whether the technology will become mainstream, which is different from your earlier question.
akvadrako 9y ago
Well quantum computing is obviously physically possible. Somehow systems evolve from a prepared input to an output predicted by quantum mechanics. However the difficulty of scaling quantum computers goes up exponentially with the number of qubits, thus we may not achieve enough success to make them practical.
- throwaway613834 9y ago
  > Well quantum computing is obviously physically possible. Well, since you mentioned this: would you mind linking me to a single demonstration of it that has been conclusively established as evidence of quantum computing? I've seen lots of D-Wave stuff but to my knowledge the experts don't actually really buy those. > However the difficulty of scaling quantum computers goes up exponentially with the number of qubits, so we might not achieve enough success to make them practical. But yes, this is more in line with what I was thinking. Even if it's possible I don't expect it will be practical (hence why I used this word in the earlier comment).
  - akvadrako 9y ago
    > would you mind linking me to a single demonstration of it I mean physics is quantum. At least, the interface between our experimental apparatuses and the micro world demonstrates all the expected speedups. Every known experiment backs this up.
    - deleted 9y ago
      [deleted]
  - mfe5003 9y ago
    Two five qubit device architectures are compared in this article. http://m.pnas.org/content/114/13/3305.full http://m.pnas.org/content/114/13/3305.full Supposedly ~17 qubit devices are on the way. None has demonstrated quantum supremacy, practical or not.
    - throwaway613834 9y ago
amelius 9y ago
I'd like to ask: what is more likely to become a reality in the next decade, fusion power or quantum computing?
- adrianN 9y ago
  In the next decade: Both won't happen. Building a fusion power plant would take at least a decade if we already knew how to do it. Quantum computers are still in the "We can find primefactors of numbers < 100" stage of research.
  - QAPereo 9y ago
    ...and we don't know how to build a fusion plant that can operate as a viable plant... and we're not just a decade away from that.
  - marcosdumay 9y ago
    As usual, Wikipedia collects everything: https://en.wikipedia.org/wiki/Timeline_of_quantum_computing https://en.wikipedia.org/wiki/Timeline_of_quantum_computing Looks like the state of the art is 17-qbits, what leads us to numbers slightly larger than 100000.
    - amelius 9y ago
      But how is it increasing? E.g., is there a Moore's law of qubits?
      - sampo 9y ago
        1998: First computers with 2 and then 3 bits of memory. 2000: Computers with 5 and 7 bits of memory. 2006: 12 bits of memory 2011: 14 bits 2017: 17 bits There is too little data to suggest anything else than a linear fit. But then again, the early stages of exponential, or logarithmic, growth can look linear. We should wait 10-20 years to get more data.
      - marcosdumay 9y ago
eru 9y ago
Quantum mechanics is a very well established theory, and quantum computing is squarely within its orthodox predictions. If quantum computing turns out to be impossible, and not just because engineering is hard, that would need a great and exciting new theory. Perhaps more exciting than quantum computing would have been.
marcosdumay 9y ago
There are 17-qbits quantum computers out there right now. So, I guess you might be wrong.
- throwaway613834 9y ago
  > There are 17-qbits quantum computers out there right now. So, I guess you might be wrong. I'm not sure: https://www.scottaaronson.com/blog/?p=3192 https://www.scottaaronson.com/blog/?p=3192 > I replied that, even though we’ve by now been around this carousel several times, I felt like the ball was now firmly in the D-Wave skeptics’ court, to reproduce the observed performance classically. And if, after a year or so, no one could, that would be a good time to start taking seriously that a D-Wave speedup might finally be here to stay—and to move on to the next question, of whether this speedup had anything to do with quantum computation, or only with the building of a piece of special-purpose optimization hardware.
  - marcosdumay 9y ago
    D-Wave has nothing to do with quantum computers (the way the word is normally used). And no relation to the numbers I posted earlier.

e19293001 9y ago

Very long time ago, talking to a person in real time 1000 miles away from you had been considered impossible.

throwaway613834 9y ago
Sure, but even more recently than that, it was imagined we'd be in flying cars by now, but we aren't. That's not really an argument.
- remline 9y ago
  Flying cars not existing has everything to do with the resources they use (public federally controlled airspace which requires every driver to be a pilot.) Quantum computers have the same barriers as other private space technology. The question to me is how long they will take to go from research toys to hobby toys which has a lot to do with cost and something to do with consumer safety.
  - throwaway613834 9y ago
    Actually I mentioned flying cars due to fuel inefficiency (I automatically assumed it was too low to make them practical) but I neglected to actually check their energy usage, and now that I just did it seems like the maximum efficiency could be on par with a normal car and it would depend on the actual trip, so my mistake on that. A better example might be artificial intelligence and the AI winters. Like the failure of machine translation despite high hopes in the 1960s. It took us some 50 years to get to where we are now with Google Translate, and it still only works well for some languages. I have no idea how close to human accuracy it will get, so I would neither be surprised if it never does, nor if it does someday. Anyway, hopefully instead of picking on the particular examples you can see that my point is obviously that people imagined we'd have a lot of things now that we still don't have the technology for today. So the fact that we've done amazing things in certain areas doesn't really say anything regarding this particular issue.
    - remline 9y ago
      I see your point. I'm just trying to point out that failures of general tech to emerge are quite different than failures of use cases. You need more of a limit preventing the emergence of a Moore's law on entanglements to really make quantum computing go away and not just solve other problems than those originally assumed to be "easy" and months away.
    - jamesrcole 9y ago
      > my point is obviously that people imagined we'd have a lot of things now that we still don't have the technology for today. So the fact that we've done amazing things in certain areas doesn't really say anything regarding this particular issue. And there's plenty of things that people said were impossible that were achieved. That doesn't tell us anything regarding quantum computing, either. Looking at what people said about past things is completely irrelevant to the prospects for some particular potential technology. The only way you can try to judge the prospects for that technology is by actually getting into the details of that technology and how it relates to our current understanding of the world.
      - throwaway613834 9y ago
        > And there's plenty of things that people said were impossible that were achieved. That doesn't tell us anything regarding quantum computing, either. Exactly. That was never my reasoning either so I'm not sure what you're refuting.
        jamesrcole 9y ago
        I'm not refuting anything. All your comments have focused on things that people have promised that haven't turned out, which gives one the impression that that somehow applies to quantum computing as well. I'm trying to paint a more balanced picture of the situation.
- aaron695 9y ago
  Flying cars have existed for 100 years. What you seem to be asking is whether the technology will become mainstream, which is different from your earlier question.

akvadrako 9y ago

Well quantum computing is obviously physically possible. Somehow systems evolve from a prepared input to an output predicted by quantum mechanics. However the difficulty of scaling quantum computers goes up exponentially with the number of qubits, thus we may not achieve enough success to make them practical.

throwaway613834 9y ago
> Well quantum computing is obviously physically possible. Well, since you mentioned this: would you mind linking me to a single demonstration of it that has been conclusively established as evidence of quantum computing? I've seen lots of D-Wave stuff but to my knowledge the experts don't actually really buy those. > However the difficulty of scaling quantum computers goes up exponentially with the number of qubits, so we might not achieve enough success to make them practical. But yes, this is more in line with what I was thinking. Even if it's possible I don't expect it will be practical (hence why I used this word in the earlier comment).
- akvadrako 9y ago
  > would you mind linking me to a single demonstration of it I mean physics is quantum. At least, the interface between our experimental apparatuses and the micro world demonstrates all the expected speedups. Every known experiment backs this up.
  - deleted 9y ago
    [deleted]
- mfe5003 9y ago
  Two five qubit device architectures are compared in this article. http://m.pnas.org/content/114/13/3305.full http://m.pnas.org/content/114/13/3305.full Supposedly ~17 qubit devices are on the way. None has demonstrated quantum supremacy, practical or not.
  - throwaway613834 9y ago

amelius 9y ago

I'd like to ask: what is more likely to become a reality in the next decade, fusion power or quantum computing?

adrianN 9y ago
In the next decade: Both won't happen. Building a fusion power plant would take at least a decade if we already knew how to do it. Quantum computers are still in the "We can find primefactors of numbers < 100" stage of research.
- QAPereo 9y ago
  ...and we don't know how to build a fusion plant that can operate as a viable plant... and we're not just a decade away from that.
- marcosdumay 9y ago
  As usual, Wikipedia collects everything: https://en.wikipedia.org/wiki/Timeline_of_quantum_computing https://en.wikipedia.org/wiki/Timeline_of_quantum_computing Looks like the state of the art is 17-qbits, what leads us to numbers slightly larger than 100000.
  - amelius 9y ago
    But how is it increasing? E.g., is there a Moore's law of qubits?
    - sampo 9y ago
      1998: First computers with 2 and then 3 bits of memory. 2000: Computers with 5 and 7 bits of memory. 2006: 12 bits of memory 2011: 14 bits 2017: 17 bits There is too little data to suggest anything else than a linear fit. But then again, the early stages of exponential, or logarithmic, growth can look linear. We should wait 10-20 years to get more data.
    - marcosdumay 9y ago

eru 9y ago

Quantum mechanics is a very well established theory, and quantum computing is squarely within its orthodox predictions. If quantum computing turns out to be impossible, and not just because engineering is hard, that would need a great and exciting new theory. Perhaps more exciting than quantum computing would have been.

marcosdumay 9y ago

There are 17-qbits quantum computers out there right now. So, I guess you might be wrong.

throwaway613834 9y ago
> There are 17-qbits quantum computers out there right now. So, I guess you might be wrong. I'm not sure: https://www.scottaaronson.com/blog/?p=3192 https://www.scottaaronson.com/blog/?p=3192 > I replied that, even though we’ve by now been around this carousel several times, I felt like the ball was now firmly in the D-Wave skeptics’ court, to reproduce the observed performance classically. And if, after a year or so, no one could, that would be a good time to start taking seriously that a D-Wave speedup might finally be here to stay—and to move on to the next question, of whether this speedup had anything to do with quantum computation, or only with the building of a piece of special-purpose optimization hardware.
- marcosdumay 9y ago
  D-Wave has nothing to do with quantum computers (the way the word is normally used). And no relation to the numbers I posted earlier.