He Said She Said – How Blogs are Changing the Scientific Discourse

The debate about D-Wave's "quantumness" shows no signs of abating, hitting a new high note with the company being prominently featured on Time magazine's recent cover, prompting a dissection of the article on Scott Aaronson's blog. This was quickly followed by yet another scoop: A rebuttal by Umesh Vazirani to Geordie Rose who recently blogged about the Vazirani et al. paper which sheds doubt on D-Wave's claim to implement quantum annealing. In his take on the Time magazine article Scott bemoans the 'he said she said' template of journalism which gives all sides equal weight, while acknowledging that the Times author Lev Grossman quoted him correctly, and obviously tries to paint an objective picture.

If I had to pick the biggest shortcoming of the Times article, my choice would have been different. I find Grossman entirely misses Scott's role in this story by describing him as "one of the closest observers of the controversy". Scott isn't just an observer in this. For better or worse he is central to this controversy. As far as I can tell, his reporting on D-Wave's original demo is what started it to begin with. Unforgettable, his inspired comparison of the D-Wave chip to a roast beef sandwich, which he then famously retracted when he resigned as D-Wave's chief critic. The latter is something he's done with some regularity, first when D-Wave started to publish results, then after visiting the company and most recently after the Troyer et al. pre-print appeared in arxiv (although the second time doesn't seem to count, since it was just a reiteration of the first resignation).

And the say sandwiches and chips go together ...Scott's resignations never seem to last long. D-Wave has a knack for pushing his buttons. And the way he engages D-Wave and associated research is indicative of a broader trend in how blogs are changing the scientific discourse. For instance, when Catherine McGeoch gave a talk about her benchmarking of the DW2, Scott did not immediately challenge her directly but took to his blog (a decision he later regretted and apologized for). Anybody who has spent more than five minutes on a Web forum knows how the immediate, yet text only, communication removes inhibitions and leads to more forceful exchanges. In the scientific context, this has the interesting effect of colliding head on with the more lofty perception of a scientist. It used to be that arguments were only conducted via scientific publications, in person such as in scientific seminars, or the occasional letter exchange. It's interesting to contemplate how corrosive the arguments between Bohr and Einstein may have turned out, if they would have been conducted via blogs rather than in person. But it's not all bad. In the olden days, science could easily be mistaken for a bloodless intellectual game, but nobody could read through the hundreds of comments on Scott's blog that day and come away with that impression. To the contrary, the inevitable conclusion will be that science arguments are fought with no less passion than the most heated bar brawl.

During this epic blog 'fight' Scott summarized his preference for the media thusly

"... I think this episode perfectly illustrates both the disadvantages and the advantages of blogs compared to face-to-face conversation. Yes, on blogs, people misinterpret signals, act rude, and level accusations at each other that they never would face-to-face. But in the process, at least absolutely everything gets out into the open. Notice how I managed to learn orders of magnitude more from Prof. McGeoch from a few blog comments, than I did from having her in the same room ..."

it is by far not the only controversy that he courted, nor is this something unique to his blog. Peter Woit continues the heretical work he started with his 'Not Even Wrong' book, Robert R. Tucci fiercely defends his quantum algorithm work when he feels he is not credited, Sabine Hossenfelder had to ban a highly qualified String theory troll due to his nastiness (she is also a mum of twins, so you know she has practice in being patient, and it's not like she doesn't have a good sense of humor). But my second favorite science blog fight also occurred on Scott's blog when Joy Christian challenge him to a bet to promote his theory that supposedly invalidates the essential non-locality of quantum mechanics due to Bell's theorem.

It's instructive to look at the Joy Christian affair and ask how a mainstream reporter could have possibly reported it. Not knowing Clifford algebra, what could a reporter do but triangulate the expert opinions? There are some outspoken smart critics that point to mistakes in Joy Christian's reasoning, yet he claims that these are based on flawed understanding and have been repudiated. The reporter will also note that doubting Bell's theorem is very much a minority position, yet such a journalist not being able to check the math himself can only fall back on the 'he said she said' template. After all, this is not a simple straight forward fact like reporting if UN inspectors found Saddam Hussein's weapons of mass distractions or not (something that surprisingly most mainstream media outside the US accomplished just fine). One cannot expect a journalist to settle an open scientific question.

The nature of the D-Wave story isn't different, how is Lev Grossman supposed to do anything but report the various stances on each side of the controversy? A commenter at Scott's blog was dismissively pointing out that he doesn't even have a science degree. As if this were to make any difference, it's not like everybody else on each side of the story doesn't boast such degrees (non-PhDs are in the minority at D-Wave).

Mainstream media reports as they always did, but unsettled scientific questions are the exception to the rule, one of the few cases when 'he said she said' journalism is actually the best format. For everything else we fortunately now have the blogs.

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51 Responses to He Said She Said – How Blogs are Changing the Scientific Discourse

  1. Speaking personally, it is odd that the “hold-outs” in Academia continue to presume that entanglement would be unlikely in such a device and therefore carries the burden of proof.

    It seems to me that this is probably due to a misunderstanding of quantum measurement theory for many of the theoreticians involved in quantum information theory and quantum computing.

    They appear to have taken the view (although they are never explicit) that “wavefunction collapse” is a real phenomenon and thus that entanglement is thus quickly destroyed in interacting systems.

    Here, I think it is wise to remember that “wavefunction collapse” is a postulate which von Neumann adjoined to the ordinary deterministic evolutionary process of the Schroedinger equation.

    The entanglement ordinarily present in many-body physics is very well tested across a large range of energy scales all the way up to the relativistic scale of inner shell electrons in heavy atoms.

    We know (or should know) this very well from atomic spectra measurements and the knowledge that distentangled treatments of the same systems do not get the right answers.

    I would suggest that this is where the detractors have their physics wrong.

    They seem not to comprehend that they are implicitly assuming the correctness of the von Neumann collapse *postulate*. Logical coherence, and experiments with cold many-body systems appear to prove otherwise. Hence, I think the detractors do possibly “protest too much”.

    Perhaps it is they who have the basic quantum physics wrong.

    • Kingsley, the idea that D-Wave’s critics fail to understand the Church of the Larger Hilbert Space, and that this dispute turns on the **interpretation of quantum mechanics**, is laughable (On the other hand, I don’t know if I’d have the strength to keep going if D-Wave’s supporters didn’t keep making such farfetched claims, so thanks, I guess!)

      OF COURSE there’s still entanglement after your quantum system has interacted with a thermal bath — if nothing else, there’s entanglement between the system and the bath! But sadly, since you don’t control the bath, that entanglement is useless for computational purposes.

      And yes, there could also be some small degree of global entanglement within the D-Wave qubits. Far from being dogmatically opposed to that possibility (because of belief in some objective collapse process?!?), as I’ve said before I think it’s more likely than not! Boixo et al., who did so much to debunk the D-Wave speedup claims, think that some global entanglement is present. Shin et al. questioned Boixo et al.’s evidence. We’ll probably learn the truth fairly soon. In any case, it’s worth stressing once again that, entanglement or no entanglement, all the serious present studies AGREE about the lack of evidence for speedup or for better scaling behavior.

      • For the record, and to be clear in response, I do think quantum physical interpretation does matter for comprehending such devices.

        Whatever your personal point of view there is a *material* difference in the physical prediction when you either put a measurement process in; or leave it out. This fact seems to elude many commentators.

        The issue is that different physical interpretations actually lead to quite different physical pictures. As you are probably aware, I lean to the camp of Schroedinger that wavefunctions in configuration space describe the underlying quantum reality of what is going on “down there”.

        However, I do not view this in the same precise way as the “multi-verse” crowd. I do not think of these problems in the same way as (say) I would understand David Deutsch to think about the problem.

        Does this matter?

        Depends on your point of view. I think so because I maintain that even a partially decohered, not very effective, annealing computer probably has enhanced algorithmic complexity. This is for purely dynamical reasons. The phase space dimension is not 2N but 2^N as you know.

        What I object to, and the reason why I am given to my own occasional rant, is that the Academic side of this debate seems very one-eyed.

        I have not seen folks (perhaps I move in the wrong circles) acknowledge the class of counter-objections I am alluding to above.

        All the same, I do not think the crescendo of blog-blathering (my own included) is unhelpful. This particular batch of dirty laundry goes all the way back to the 1927 Solvay Congress and some unfinished business.

        To get that into the open so that people square up and debate it on scientific grounds is a good thing.

        Yours in perpetual entanglement, Kingsley

    • Jason Dick says:

      It’s not necessary to believe that wavefunction collapse is real to be skeptical that coherent entanglement has been maintained. To maintain coherence, you need pretty strict isolation of the quantum system.

      Issues like debates over what people believe about the various interpretations of quantum mechanics are irrelevant to this. What matters is whether or not the computer has been able to achieve algorithmic scaling that only quantum computers (so far) can achieve. I haven’t investigated the matter in detail, so I really have no opinion one way or the other on the matter. But it is the tests of computational scaling that are important, not anybody’s particular beliefs about the nature of quantum mechanics.

      P.S. The many worlds interpretation is the correct one :P

      • Henning Dekant says:

        Which of the many worlds interpretations? There are so many …

      • So Many-Worlds is “correct” is it? Interesting.

        So “coherent entanglement” is necessary for “algorithmic scaling”???

        Really? In which particular one of the many worlds is that true right now?

        Perhaps it would be good to think about this more deeply.

        Protein folding is an example of an algorithmically complex computation which Nature accomplishes with high reliability quite effortlessly.

        Think carefully about how Nature accomplishes this calculation.

        You assemble a protein from amino acids, place it in a heat bath and allow that molecule to descend by stages to the ground state.

        This happens to be one global minimum among many local minima. It happens in a heat bath at room temperature.

        It is an example of a physical process analogous to simulated annealing and the algorithmic complexity of the computation is high.

        Now tell me again that coherent quantum entanglement is required to accomplish a high “complexity” physical computation.

        I see a lot of people in physics make outrageous claims about what is or is not necessary to achieve a practically useful computational device.

        The common element among such people is that they never ever get around to building anything that actually works.

        So 21 = 3 * 7

        Gee, that was a complex calculation!

        • Jason Dick says:

          It has nothing to do with complexity. It has to do with performance. Take integer factorization, for example. Imagine that a hypothetical quantum computer and a classical computer can factor an integer with 10 digits in the same amount of time. How long would each take to factor a number with, say, 100 digits?

          A classical computer, using the best-known algorithm, would take at least twenty thousand times as long to solve a 100-digit number as a 10-digit number.

          A quantum computer, using Shor’s algorithm, would take a mere thousand times longer.

          For larger numbers, the quantum computer gains even more of an advantage.

          That’s a concrete, measurable statement. Is the D-Wave capable of scaling like a quantum computer? Or is it incapable of beating the scaling of a classical computer?

          • Nonsense!

            It has *everything* to do with algorithmic complexity. A quantum evolution can be emulated by a classical evolution in a mirroring phase space. That is the embedding theorem I proved 20 plus years ago. It is rather silly to say classical computers cannot do what quantum computers can do. Ay quantum dynamical system can be though of as being modeled (and emulated) as an equivalent integrable classical system on an equivalent phase space.

            That system is not balls and sticks – it is abstract – but it satisfies Hamilton’s dynamics.

            The point, and merit, of a quantum computer is that it is easier to access a “higher dimensional” phase space through quantum interactions that entangle the underlying “components”.

            I get annoyed when I hear this stuff.

            Go do some math, my friend! This really is a very stupid controversy perpetuated by people who seem not to understand physics very well and are ignorant of algorithmic complexity theory.

            I re-iterate my example of actual real live protein folding in Nature.

            Here is a small homework problem. Go download NAMD code… set up a sim-anneal on that dynamical system and try to “solve” protein folding. When you do that… pack a lunch.

            Then think about what I said earlier.

            In real life, protein folding is a breeze for Nature to solve. That is because the dynamics is actually happening on a fantastically larger dimensional phase space than what the elementary NAMD description is attempting. A real protein is made of quantum stuff probing the ground state.

            The trouble that I see with all the dogma in quantum computing is that the folks involved are not thinking clearly or hard about what “computation” means.

            Folks are assuming that it involves a strictly controlled “evolutionary path” of gates and logic cranking through a procedure towards the solution. Of course it is hard, energy expensive, and delicate to attempt a computation via this approach.

            I believe (and I think von Neuman did also) that Nature is a great deal smarter than that.

            Natural systems: protein folding; the brain; natural feedback control systems; involve an inherently stable thermodynamic solution. Find minimum energy, subject to constraint under perturbation.

            The point is that you get to the unique ground state regardless of the pathway.

            This is what folks are missing with all their error correction nonsense and other overly elaborate designs. They are neglecting the simple extremal principles at work in all natural systems.

            The beauty of thermodynamics is that the target “end state” is robust to the path taken.

            You get there *because* of the presence of dissipative perturbations.

          • Jason Dick says:

            Kingsley, if what you say is true, then why does encryption work at all?

            There is no question that a classical computer can emulate a quantum computer. The question is whether or not the classical computer can achieve the same scaling as the quantum computer. Until you show me an algorithm that can be run on a classical computer that factors integers in O(D^3) time (D = number of digits), your statement that quantum computers can be emulated is meaningless.

        • pcs says:

          I think what you are missing is that you are assuming thermodynamic equilibrium for the protein example.
          And that is quite demonstrably absent in how proteins function “in Nature”. These are non-equilibrium processes, and I think that disqualifies this example to play a role in this discussion.

          But, please educate me if you think I am wrong,

  2. Ramsey44 says:

    Wow, just WOW!! This is a great piece that describes what’s really going on here and put eloquently. Wish I could have written it, thank you!

  3. It is probably asking you too much to be even-handed, but the first obligation of any science journalist is to get at least the non-scientific facts right. You write: “… when Joy Christian challenged him to a bet to promote his theory that supposedly invalidates the essential non-locality of quantum mechanics due to Bell’s theorem.” This is grossly incorrect, even if we ignore the non-scientific half of your cryptic sentence. I did not challenge Aaronson out of the blue. He had been badmouthing me on his blog for a long time (for two years, to be precise, since the 2009 FQXi conference in Portugal). I did not say anything for two years, for his badmouthing was of no consequence to me. But then some lady sends me an email and invites me to comment of his blog were some silly discussion on Bell’s theorem was going on. So I entered the discussion and wrote a comment on Aaronson’s blog, just like many other people were doing. But the next thing I saw was quite unexpected and shocking. As is often the case with him, his kneejerk reaction was to start an entirely new blog entry—a full-blown diatribe against me—full of ad hominems, deliberately intended to denigrate me personally as well as my perfectly respectable scientific work. As you have correctly alluded to, however, his uninformed and unprofessional critique of my scientific work has been entirely repudiated by several authors: http://libertesphilosophica.info/blog/.

    • Henning Dekant says:

      Joy, sorry if you feel I misrepresented your side of the story. I kept it brief, as I just point to it as yet another prime example of how blogs are changing the scientific discourse.

  4. Harland says:

    Let me guess: you’re politically hardcore left-wing, otherwise the Iraq comment wouldn’t have been included and the “weapons of mass distraction” “joke” wouldn’t have been included either.

    Serious question: how do left-wing scientists deal with science or scientists that refute their political opinions? Give me a few examples of science that has changed society away from the pre-made conclusions of left-wing politics in the past decade or so. Huh? There aren’t any?

    Now, list science that proves inescapably that these same opinions aren’t just opinions, but irrefutable facts of nature. Whoa! All of it?

    What a coinky-dink. It’s almost as if when you start with blinders you don’t even realize you’re wearing, you bias yourself in ways you never imagined, and produce results that align with your pre-existing prejudices.

    “Of all the illusions that beset mankind none is quite so curious as that tendency to suppose that we are mentally and morally superior to those who differ from us in opinion.”
    – Elbert Hubbard

    “Some ideas are so stupid that only intellectuals believe them.”
    – George Orwell

    • Henning Dekant says:

      “Let me guess: you’re politically hardcore left-wing”

      No, I am just a German living in Canada. Definitely don’t consider myself particularly left leaning, and usually avoid politics on this blog.

      Just needed a clear example for when the ‘he said she template’ clearly fails the public, and I cannot think of a more stinging recent example as when the question of war hangs in the balance.

      • Germans living in Canada! What is the world coming to?

        People will be having Maple Syrup on Pumpernickel next.

        I think this whole free exchange of people and ideas thing has gone too far. We should all eat white bread and go to Church on Sunday.

        • Henning Dekant says:

          Only in upside-down Oz land could anybody come up with such a travesty as “Maple Syrup on Pumpernickel”!

          Just for the record, I put Maple Syrup in my coffee :-)

  5. Oregon Pet. says:

    I totally agree, there are many great resources online and we don’t need to rely on the mainstream media to the facts on global warming. My favorite online source of comprehensive, up to date and authoritive facts is the NIPCC Report. http://nipccreport.org

    • Henning Dekant says:

      Bashing the mainstream media is if of course quite popular on blogs, but I find mostly they get the climate issue right, despite well funded push-back (such as your slick web site).

      The problem nowadays is less shoddy journalism but not enough journalism. Cost cutting took its toll on the quality.

  6. Henning, I think IS an alternative to “he said, she said” journalism: namely, “he said, she said, now let me try to use my own powers of reasoning and investigative skills as a journalist to figure out where the truth probably lies.” And if you think that’s impossible when reporting on D-Wave, then how do you explain Will Bourne’s Inc. article?

    • Henning Dekant says:

      Have to disagree on that. Bourne simple adopts one side of the expert opinions when he writes “Rose may be unable to overthrow the laws of physics”. This clearly prejudges that they try to do the impossible. But the question if their machine can achieve a quantum speed-up is not settled, even if you have good reasons to assign it a low probability.

  7. vznvzn says:

    a proud target of scotts ire! scott declared me blocked from writing comments on his blog for forcefully criticizing his brash strawman betting/wagering announcement penchant as unprofessional/unscientific (afaict). thinskinned, can dish it out but cant take it!

    yes science is entering a new period of no-holds-barred behind-the-scenes communication. science has always been messy & about debates as the colorful/historic bohr-einstein debate attests. the gloves are off. blogs have both pros and cons in this shift. scott is a colorful persona but he gets carried away and has a real dogmatic/rigid side. if he allowed his critics to write comments freely on his blog it would help keep his periodic overreaction(s) less extreme.

  8. It is contradictory to ask for a less egotistic attitude in a society based on antagonism and prevailence…

    “In the Kamigata area, they have a sort of tiered lunchbox they use for a single day when flower viewing. Upon returning, they throw them away, trampling them underfoot. The end is important in all things.”
    ― Yamamoto Tsunetomo, Hagakure: The Book of the Samurai

  9. vznvzn says:

    ps isnt anyone else getting tired of scotts armchair quarterbacking & endless shrill ranting on DWave that got old years ago! think he might need to see a psychologist about all his years inner emotional angst on the subj! maybe its the difference between engineering vs theorizing! …. geordie rose/Dwave follow the mottos:

    lead, follow, or get out of the way!

    and

    the pioneers are the ones with arrows in their backs!

  10. vznvzn says:

    those who can, do; those who cant, TEACH

  11. I was thinking of posting a comment explaining what led to vznvzn’s banning from my blog, but probably the contentless ad hominems above make the case more eloquently than I would have.

    • vznvzn says:

      HI SCOTT LOOK AT THIS! A BLOG WITH UNRESTRICTED FREE SPEECH!!! WHAT A @#$% CONCEPT HUH!!

    • vznvzn says:

      WOW all this crazy no holds barred dialog is just so INSPIRING just had a flash of an idea… maybe Ill write an entire blog comparing one of SCOTTs papers to a ROAST BEEF SANDWICH!!! lets see my all time favorite so far is the one about how complexity theorists should get into PHILOSOPHY! or maybe it was the other way around!! @#$% its so hard to keep it all straight!!

      or hell maybe Ill just toss caution to the wind and write some poetry comparing SCOTT HIMSELF to a ROAST BEEF SANDWICH!! of course one might write a single blog but it would barely make a DENT compared to the easily TENS OF THOUSANDS OF EXCORIATING WORDS that SCOTT has written on DWAVE!! what the @#$% does one do with such an oevre anyway? heck maybe he can collect them into a single volume by ELSEVIER and publish them for a few hundred bucks!!! BET LOTS OF HIS SCIENTIST FRIENDS WOULD BUY IT!! OR AT LEAST LOBBY FOR THEIR UNIVERSITIES TO HAND OVER THE $$$…. what a BARGAIN that would be!!!

      • Henning Dekant says:

        Look I get it, you are angry at Scott for permanent blog banishment, and your disagree with him on D-Wave.

        But before you subject us to yet another all caps, bold font rant, or even worse a poem, I suggest you make your case in a more persuasive manner.

        Scott used a lot of rhetoric devices over the years, to the extend that you feel these were unfair to D-Wave you could for instance compile them in a blog post. Would be much more efficient than railing against him here.

        • vznvzn says:

          hi HD your blog was cited on slashdot, mine wasnt, wink (HUGE CONGRATULATIONS ON THAT DUDE!! SUCH A COUP DESERVES CAPS DONT YOU THINK?)…. typed a wrong character and it messed up my last msg so the full “rhetorical impact” couldnt be appreciated :sad: …. did once write up a blog related to scott aaronson here, solitons, cellular automata, qm, & disagreeing with scott aaronson…. it would be incredibly time consuming… just dont have the TIME to do a archnemesis act on AARONSON the same way he’s done on ROSE… can only afford a few SELECT INTERVENTIONS wink!

          continued: what the @#$* does one do with such an oevre [of dwave rants] anyway? heck maybe scott can collect all of it into a single volume by ELSEVIER and publish them for a few hundred bucks!!! BET LOTS OF HIS SCIENTIST FRIENDS WOULD BUY IT!! OR AT LEAST LOBBY FOR THEIR UNIVERSITIES TO HAND OVER THE $$$!! what a BARGAIN that would be!!!

          • vznvzn says:

            omg sigh again continued: what the @#$% does one do with such an oevre [of dwave rants] anyway? heck maybe scott can collect all of it into a single volume by ELSEVIER and publish them for a few hundred bucks!!! BET LOTS OF HIS SCIENTIST FRIENDS WOULD BUY IT!! OR AT LEAST LOBBY FOR THEIR UNIVERSITIES TO HAND OVER THE $ $ $ !! what a BARGAIN that would be!!!

          • vznvzn says:

            arrghghghg a rare free speech blog but the character substitution totally screwing it up!!! ack foiled by a stupid comment editor, giving up!!!

          • vznvzn says:

            ps recent blog on DWave with lots of links that tastefully leaves out WHATS-HIS-NAME’S OPPOSITIONAL DEFIANCE…. dwave/inception of the qm computing dream, compares Rose/Dwave to Babbage….

        • Henning Dekant says:

          You make a good case that I need to install a plug-in that allows for the editing of comments after posting.

          Always pretty cool to get a plug on /. although it ain’t quite what it used to be (used to be over 10K views a day but not anymore just runs into the thousands).

          As to Babbage, maybe he anticipated this kind of blow-back and that’s why he never finished his machine :-)

          • vznvzn says:

            HD– wordpress itself doesnt seem to have comment editing, that would be nice (you seem to be running an amalgamation of wordpress + plugins?)…. hey dont think facebook has comment editing either does it? google+ has it, what a great feature! now how about a social network that can simply list your *liked* posts somewhere? or sort/filter your feed by likes on posts like stackexchange votes! hey this is software engineering, not rocket science right? hell oh well guess sometimes software engr is like rocket science!

            comment entry here is messing up on special characters….maybe a overeager latex plugin or something? oh MAN cant insert any cartoon swearing, aieeeeeee, the kiss of death for me! guess youre safe for now then!

            multiple slashdot cites on here over the years? very impressive, green with envy :mrgreen: still a slashdot virgin, my current blog wink

            re Babbage, his story and Dwave certainly have many significant parallels, that’d surely be worthy of a blog, might do that sometime. maybe gotta get a book on him, is there one? or maybe its already lying around here somewhere & forgot to read it all! its too bad how little CS students are taught about him, his story is quite relevant today & to silicon valley rise etc…. in a way babbage was one of the 1st inventors of so-called “disruptive technology”….

          • vznvzn says:

            & ps would guess ARCHNEMESIS SCOTT has neglected to mention Babbage a single time in all his “rhetorical devices” referring to Dwave employed over the years! hint: ITS A LOT MORE APPLICABLE THAN ROAST BEEF SANDWICHES. geez, how ridiculous can you get? maybe SCOTT did not follow that basic advice: NEVER BLOG WHEN YOU ARE HUNGRY :razz:

  12. Sol Warda says:

    Jason: Just curious to know according to your best calculations, how long would it take a Gate model universal quantum computer to factor RSA-2048 bits, which is 617 decimal digits long. After you give me your estimate, I will tell what Dr. John Preskill said in a recent talk. Thanks.

    • Jason Dick says:

      I’d have to know its performance on a smaller input first.

      Shor’s algorithm has complexity of O(D^3) (where D is the number of digits/bits). So a quantum computer would be able to solve RSA-2048 in about eight times the time it takes to solve RSA-1024 (using no additional computational units).

  13. Sol Warda says:

    Jason: Thanks for your answer. Dr. John Preskill in a recent talk at the University of Waterloo, clearly said and displayed the full 617-digit number on the screen, that a Gate model universal QC would factor that number in 2 seconds!. How did he get that timing?. Just curious. Thanks.

    • Jason Dick says:

      I really don’t know. Was this a theoretical estimate, or a real test? If a theoretical estimate, he probably used the exact same scaling relationship I just used (this can be read directly from Wikipedia) along with some basic assumptions about the processing speed of the quantum computer.

  14. Sol Warda says:

    Jason: I don’t really know. He simply displayed this number on his screen & compared the time that a classical computer, which he said would take the age of universe, vs. a QM which would factor it in 2 seconds. I was very surprised that it would do it that fast. But even if we take the number of bits cubed, or 2048^3 = 8,589,934,592, what does this number mean?. Is it the Clock speed of the computer or the chip, in GHZ?, which sounds plausible, but I have no idea. Thanks again.

    • Jason Dick says:

      No, not quite. The scaling relationship only tells you how the performance changes with input size. It says nothing about absolute performance, which depends on a whole lot of factors.

      For example, any quantum computer is rather likely to process more than just one single bit of the input at a time. Furthermore, the quantum computer might not run at any fixed frequency (running processors at a fixed frequency is an artificial construct intended to make chip design easier: it isn’t even necessary for silicon processors, and there are some significant advantages to not having any kind of clock).

  15. Sol Warda says:

    Henning: You may point this link of D-Wave, which is on their website, to one of the biggest skeptics that you know, and who regularly comments on Scott’s blog, and ask him to run this Lockheed code on their Laptop, or their Desktop for that matter. Let’s see how far they get. Here is the link: http://www.dwavesys.com/our-company/customers

    • Henning Dekant says:

      Doubt very much that this code is publicly available, but thanks for pointing me to the customer story. That’s the kind of marketing collateral that I was waiting for.

  16. Sol Warda says:

    Hi Henning: I’m very sorry for being the instigator of the row you had with some of those thin-skinned people, when presented with good evidence in favour of D-Wave. They ganged up on you like a “pack of hyenas”, in the words of Robert Tucci. As you know they did the same thing to me a couple of weeks ago when I tried to question the motives of IBM & their scientists in attempting to discredit of couple of papers about D-wave. I tried to detract attention away from you by showing them the writing about Lockheed code, but only one of them, Greg Kuperberg, took the bait. Even he said “I don’t know what to make of this”, and blamed the whole thing on D-Wave people, that it could be just “made up by them”. At any rate, I’m sorry again and please try to put it behind you. Thanks.

  17. Copenhagen says:

    In case the readers of this blog are wondering, D-Wave Systems does have supporters at MIT.

    D-Wave named to MIT Technology Review’s 2014 List of the 50 Smartest Companies-
    http://www.technologyreview.com/featuredstory/524671/50-smartest-companies-2014/

    D-Wave is giving a Closing Keynote at the 2014 MIT Sloan Tech Conference -
    http://disruptinglife.mitsloantech.com/

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