6 ms·

Considering the much-touted "quantum supremacy" achievement was extremely contrived, it seems like the hype has gotten far ahead of the reality.

xxpor 5y ago
I think for a lot of people the real question is how far ahead the intel agencies (really, the NSA) are. How many years will there be a super mega top secret quantum computer sitting in the basement of Ft. Meade breaking DH before someone figures it out?
- kvathupo 5y ago
  Considering government pay and bureaucracy, this is probably unlikely today
- ryan93 5y ago
  No. the smartest people work for universities or private companies. people would know if top scientists were leaving for the NSA
  - xxpor 5y ago
    That's true generally, but I thought I saw some stat that NSA hired some crazy % of the math PhDs in the US (like 30%+). I also thought the national labs were considered pretty good places to work.
  - thehappypm 5y ago
    "Why shouldn't I work for the N.S.A.? That's a tough one, but I'll take a shot. Say I'm working at N.S.A. Somebody puts a code on my desk, something nobody else can break. Maybe I take a shot at it and maybe I break it. And I'm real happy with myself, cause I did my job well. But maybe that code was the location of some rebel army in North Africa or the Middle East. Once they have that location, they bomb the village where the rebels were hiding and fifteen hundred people I never met, never had no problem with, get killed. Now the politicians are sayin', "Oh, send in the Marines to secure the area" cause they don't give a shit. It won't be their kid over there, gettin' shot. Just like it wasn't them when their number got called, cause they were pullin' a tour in the National Guard. It'll be some kid from Southie takin' shrapnel in the ass. And he comes back to find that the plant he used to work at got exported to the country he just got back from. And the guy who put the shrapnel in his ass got his old job, cause he'll work for fifteen cents a day and no bathroom breaks. Meanwhile, he realizes the only reason he was over there in the first place was so we could install a government that would sell us oil at a good price. And, of course, the oil companies used the skirmish over there to scare up domestic oil prices. A cute little ancillary benefit for them, but it ain't helping my buddy at two-fifty a gallon. And they're takin' their sweet time bringin' the oil back, of course, and maybe even took the liberty of hiring an alcoholic skipper who likes to drink martinis and fuckin' play slalom with the icebergs, and it ain't too long 'til he hits one, spills the oil and kills all the sea life in the North Atlantic. So now my buddy's out of work and he can't afford to drive, so he's got to walk to the fuckin' job interviews, which sucks cause the shrapnel in his ass is givin' him chronic hemorrhoids. And meanwhile he's starvin', cause every time he tries to get a bite to eat, the only blue plate special they're servin' is North Atlantic scrod with Quaker State. So what did I think? I'm holdin' out for somethin' better. I figure fuck it, while I'm at it why not just shoot my buddy, take his job, give it to his sworn enemy, hike up gas prices, bomb a village, club a baby seal, hit the hash pipe and join the National Guard? I could be elected president." Good Will Hunting
- daxfohl 5y ago
  Not yet. The way this kind of stuff usually works is that, as we get closer we'll see some high-profile researchers suddenly quit their jobs to go work on "something else".
  - xxpor 5y ago
    Yeah that'd make sense. Thinking about it, that's exactly what happened with the Manhattan Project.
reikonomusha 5y ago
Just so nobody is misinterpreting what you’re saying (that somehow the quantum supremacy result was a farce): Quantum supremacy is a very important milestone in quantum computing. Being contrived or academic is fine because it’s intended to be fundamental science. The term “supremacy” was already long a part of the quantum computing lexicon before the result was achieved, and it has essentially a precise mathematical definition. I think it’s an unfortunate term, but it certainly wasn’t invented for the occasion. Some people blew the result out of proportion, making claims that finally quantum computers are provably useful/the best/etc. Google (who got the result) know these claims are not true, but in their typical character, turned a blind eye to the hype that ensued, because who doesn’t want free press?
- kvathupo 5y ago
  Don't we have a provable guarantee in the case of the traversal of glued trees via oracle, i.e. no classical algorithm has lower query-complexity? (Granted, the same can't be said for Grover's) See section 16.4 of these notes (pdf warning) [1]. [1] - http://www.cs.umd.edu/~amchilds/qa/qa.pdf http://www.cs.umd.edu/~amchilds/qa/qa.pdf
  - simiones 5y ago
    These are two somewhat separate problems: 1. Do theoretical quantum computers have different properties than theoretical classical computers? (or, QBP = P? ) 2. Does some particular physical device show the properties associated with a theoretical quantum computer? Of course, if 1 is false, than 2 is more or less irrelevant. However, even if 1 true, that still leaves the question of 2 for any particular device. The Google and Chinese experiments have proven 2 for their own particular devices. This is an important milestone not just for these particular devices, but also because, prior to this, there was also a question 3: do QM systems actually exhibit the properties of a theoretical quantum computer? After the Google result, this has been almost entirely put to rest: the answer is yes.
    - reikonomusha 5y ago
      Excellent explanation and separation of concerns.
simiones 5y ago
The quantum supremacy milestone was still extremely important, even if it doesn't in any way mean that we are close to a working QC. Before this milestone, there were still reasons to believe that quantum computers could not, in principle, beat classical computers, that there is some fundamental limitation of the universe that would actually prevent quantum effects from making a QC work. After this milestone, the only "hope" for such a fundamental limitation lies in the area of quantum error correction - the possibility that, somehow, you would lose the theoretical speed-up from QC by having to re-run the algorithm enough times to get an accurate enough response. As Scott Aaronson explains, while disappointing in terms of QC, this would also be extremely exciting for quantum mechanics itself and for our understanding of the universe. So, the Google and Chinese quantum supremacy demonstrations, while useless as actual computations, serve a very important role in showing that actual quantum computers have properties that can't be replicated by classical computers, which was not proven before these experiments were run. Equivalently, you can say that these experiments have proven that the physical systems being called "quantum computers" have at least some properties of the theoretical mathematical concept of a quantum computer - something that no previous systems had proven conclusively. In this way, this can also be seen as a new test of Quantum Mechanics' predictions, since it proves once again that real physical systems do exhibit some of the complex behaviors predicted by the maths.
- sampo 5y ago
  > Before this milestone, there were still reasons to believe that quantum computers could not, in principle, beat classical computers The laws of Quantum Mechanics clearly allow quantum computers. So those beliefs must have included something that goes beyond known physics i.e. the assumption of some supernatural effect?
  - reikonomusha 5y ago
    The laws of Newtonian physics also “allow” frictionless, spherical cows. The laws of relativity and nuclear physics “allow” a tablespoon of salt to provide 453 GWh of energy.
  - jlokier 5y ago

xxpor 5y ago

I think for a lot of people the real question is how far ahead the intel agencies (really, the NSA) are. How many years will there be a super mega top secret quantum computer sitting in the basement of Ft. Meade breaking DH before someone figures it out?

kvathupo 5y ago
Considering government pay and bureaucracy, this is probably unlikely today
ryan93 5y ago
No. the smartest people work for universities or private companies. people would know if top scientists were leaving for the NSA
- xxpor 5y ago
  That's true generally, but I thought I saw some stat that NSA hired some crazy % of the math PhDs in the US (like 30%+). I also thought the national labs were considered pretty good places to work.
- thehappypm 5y ago
  "Why shouldn't I work for the N.S.A.? That's a tough one, but I'll take a shot. Say I'm working at N.S.A. Somebody puts a code on my desk, something nobody else can break. Maybe I take a shot at it and maybe I break it. And I'm real happy with myself, cause I did my job well. But maybe that code was the location of some rebel army in North Africa or the Middle East. Once they have that location, they bomb the village where the rebels were hiding and fifteen hundred people I never met, never had no problem with, get killed. Now the politicians are sayin', "Oh, send in the Marines to secure the area" cause they don't give a shit. It won't be their kid over there, gettin' shot. Just like it wasn't them when their number got called, cause they were pullin' a tour in the National Guard. It'll be some kid from Southie takin' shrapnel in the ass. And he comes back to find that the plant he used to work at got exported to the country he just got back from. And the guy who put the shrapnel in his ass got his old job, cause he'll work for fifteen cents a day and no bathroom breaks. Meanwhile, he realizes the only reason he was over there in the first place was so we could install a government that would sell us oil at a good price. And, of course, the oil companies used the skirmish over there to scare up domestic oil prices. A cute little ancillary benefit for them, but it ain't helping my buddy at two-fifty a gallon. And they're takin' their sweet time bringin' the oil back, of course, and maybe even took the liberty of hiring an alcoholic skipper who likes to drink martinis and fuckin' play slalom with the icebergs, and it ain't too long 'til he hits one, spills the oil and kills all the sea life in the North Atlantic. So now my buddy's out of work and he can't afford to drive, so he's got to walk to the fuckin' job interviews, which sucks cause the shrapnel in his ass is givin' him chronic hemorrhoids. And meanwhile he's starvin', cause every time he tries to get a bite to eat, the only blue plate special they're servin' is North Atlantic scrod with Quaker State. So what did I think? I'm holdin' out for somethin' better. I figure fuck it, while I'm at it why not just shoot my buddy, take his job, give it to his sworn enemy, hike up gas prices, bomb a village, club a baby seal, hit the hash pipe and join the National Guard? I could be elected president." Good Will Hunting
daxfohl 5y ago
Not yet. The way this kind of stuff usually works is that, as we get closer we'll see some high-profile researchers suddenly quit their jobs to go work on "something else".
- xxpor 5y ago
  Yeah that'd make sense. Thinking about it, that's exactly what happened with the Manhattan Project.

reikonomusha 5y ago

Just so nobody is misinterpreting what you’re saying (that somehow the quantum supremacy result was a farce): Quantum supremacy is a very important milestone in quantum computing. Being contrived or academic is fine because it’s intended to be fundamental science. The term “supremacy” was already long a part of the quantum computing lexicon before the result was achieved, and it has essentially a precise mathematical definition. I think it’s an unfortunate term, but it certainly wasn’t invented for the occasion. Some people blew the result out of proportion, making claims that finally quantum computers are provably useful/the best/etc. Google (who got the result) know these claims are not true, but in their typical character, turned a blind eye to the hype that ensued, because who doesn’t want free press?

kvathupo 5y ago
Don't we have a provable guarantee in the case of the traversal of glued trees via oracle, i.e. no classical algorithm has lower query-complexity? (Granted, the same can't be said for Grover's) See section 16.4 of these notes (pdf warning) [1]. [1] - http://www.cs.umd.edu/~amchilds/qa/qa.pdf http://www.cs.umd.edu/~amchilds/qa/qa.pdf
- simiones 5y ago
  These are two somewhat separate problems: 1. Do theoretical quantum computers have different properties than theoretical classical computers? (or, QBP = P? ) 2. Does some particular physical device show the properties associated with a theoretical quantum computer? Of course, if 1 is false, than 2 is more or less irrelevant. However, even if 1 true, that still leaves the question of 2 for any particular device. The Google and Chinese experiments have proven 2 for their own particular devices. This is an important milestone not just for these particular devices, but also because, prior to this, there was also a question 3: do QM systems actually exhibit the properties of a theoretical quantum computer? After the Google result, this has been almost entirely put to rest: the answer is yes.
  - reikonomusha 5y ago
    Excellent explanation and separation of concerns.

simiones 5y ago

The quantum supremacy milestone was still extremely important, even if it doesn't in any way mean that we are close to a working QC. Before this milestone, there were still reasons to believe that quantum computers could not, in principle, beat classical computers, that there is some fundamental limitation of the universe that would actually prevent quantum effects from making a QC work. After this milestone, the only "hope" for such a fundamental limitation lies in the area of quantum error correction - the possibility that, somehow, you would lose the theoretical speed-up from QC by having to re-run the algorithm enough times to get an accurate enough response. As Scott Aaronson explains, while disappointing in terms of QC, this would also be extremely exciting for quantum mechanics itself and for our understanding of the universe. So, the Google and Chinese quantum supremacy demonstrations, while useless as actual computations, serve a very important role in showing that actual quantum computers have properties that can't be replicated by classical computers, which was not proven before these experiments were run. Equivalently, you can say that these experiments have proven that the physical systems being called "quantum computers" have at least some properties of the theoretical mathematical concept of a quantum computer - something that no previous systems had proven conclusively. In this way, this can also be seen as a new test of Quantum Mechanics' predictions, since it proves once again that real physical systems do exhibit some of the complex behaviors predicted by the maths.

sampo 5y ago
> Before this milestone, there were still reasons to believe that quantum computers could not, in principle, beat classical computers The laws of Quantum Mechanics clearly allow quantum computers. So those beliefs must have included something that goes beyond known physics i.e. the assumption of some supernatural effect?
- reikonomusha 5y ago
  The laws of Newtonian physics also “allow” frictionless, spherical cows. The laws of relativity and nuclear physics “allow” a tablespoon of salt to provide 453 GWh of energy.
- jlokier 5y ago