I/31sCqctH7HL.jpg' alt='Elementary Textbook On Physics Landsberg Pdf' title='Elementary Textbook On Physics Landsberg Pdf' />Truth finally starts to emerge. Wrap Up June 5 This will be my final update on this post really, since the discussion seems to have reached a point where not much progress is being made, and since Id like to oblige the commenters whove asked me to change the subject. Let me try to summarize the main point Ive been trying to get across this whole time. Ill call the point. D Wave founder Geordie Rose claims that D Wave has now accomplished its goal of building a quantum computer that, in his words, is better at something than any other option available. This claim has been widely and uncritically repeated in the press, so that much of the nerd world now accepts it as fact. However, the claim is not supported by the evidence currently available. It appears that, while the D Wave machine does outperform certain off the shelf solvers, simulated annealing codes have been written that outperform the D Wave machine on its own native problem when run on a standard laptop. More research is needed to clarify the issue, but in the meantime, it seems worth knowing that this is where things currently stand. In the comments, many people tried repeatedly to change the subject from to various subsidiary questions. For example isnt it possible that D Waves current device will be found to provide a speedup on some other distribution of instances, besides the one that was tested  Even if not, isnt it possible that D Wave will achieve a genuine speedup with some future generation of machines  Did it make business sense for Google to buy a D Wave machine  What were Googles likely reasons  Whats D Waves current value as a company  Should Cathy Mc. Geoch have acted differently, in the type of comparison she agreed to do, or in how she communicated about its results  Should I have acted differently, in my interaction with Mc. Geoch And, Im afraid to say, I jumped in to the discussion of all of those questionsbecause, lets face it, there are very few subjects about which I dont have an opinion, or at least a list of qualified observations to make. In retrospect, I now think that was a mistake. It would have been better to sidestep all the other questionsnot one of which I really know the answer to, and each of which admits multiple valid perspectivesand just focus relentlessly on the truth of assertion. Heres an analogy imagine that a biotech startup claimed that, by using an expensive and controversial new gene therapy, it could cure patients at a higher rate than with the best available conventional drugsbasing its claim on a single clinical trial. Imagine that this claim was widely repeated in the press as an established fact. Now imagine that closer examination of the clinical trial revealed that it showed nothing of the kind it compared against the wrong drugs. And imagine that a more relevant clinical trialmostly unmentioned in the presshad also been done, and discovered that when you compare to the right drugs, the drugs do better. Imagine that someone wrote a blog post bringing all of this to public attention. And now imagine that the response to that blogger was the following aha, but isnt it possible that some future clinical trial will show an advantage for the gene therapymaybe with some other group of patients  Even if not, isnt it possible that the startup will manage to develop an effective gene therapy sometime in the future  Betcha didnt consider that, did you  And anyway, at least theyre out there trying to make gene therapy work  So we should all support them, rather than relentlessly criticizing. And as for the startups misleading claims to the public  Oh, dont be so nave thats just PR. If you cant tune out the PR and concentrate on the science, thats your own damn problem. In summary, the real issue isnt what some clinical trial did or didnt show its you and your hostile attitude. In a different context, these sorts of responses would be considered strange, and the need to resort to them revealing. Marshall Tucker Band 1973 Rare there. But the rules for D Wave are different. Interestingly, in excusing D Waves statements, some commenters explicitly defended standards of intellectual discourse so relaxed that, as far as I could tell, just about anything anyone could possibly say would be OK with themexcept of course for what I say on this blog, which is not OK  It reminds me of the central tenet of cultural relativism that there exist no universal standards by which any culture could ever be judged good or bad, except that Western culture is irredeemably evil. Update June 4 Matthias Troyer who, unfortunately, still cant comment here for embargo reasons has asked me to clarify that its not he, but rather his postdoc Sergei Isakov, who deserves the credit for actually writing the simulated annealing code that outperformed the D Wave machine on the latters own home turf i. QUBO instances with the D Wave constraint graph. The quantum Monte Carlo code, which also did quite well at simulating the D Wave machine, was written by Isakov together with another of Matthiass postdocs, Troels Rnnow. Update June 3 See Cathy Mc. Geochs response here and here, and my response to her response. Yet More Updates June 2 Alex Selby has a detailed new post summarizing his comparisons between the D Wave device as reported by Mc. Geoch and Wang and his own solverfinding that his solver can handily outperform the device and speculating about the reasons why. In other news, Catherine Mc. Geoch spoke on Friday in the MIT quantum group meeting. Incredibly, she spoke for more than an hour, without once mentioning the USC results that found that simulated annealing on a standard laptop when competently implemented handily outperformed the D Wave machine, or making any attempt to reconcile those results with hers and Wangs. Instead, Mc. Geogh used the time to enlighten the assembled experts about what quantum annealing was, what an exact solver was, etc. I left without asking questions, not wanting to be the one to instigate an unpleasant confrontation, andIll admitquestioning my own sanity as a result of no one else asking about the gigantic elephant in the room. More Updates May 2. Happy 2. 5th birthday to me  Among the many interesting comments below, see especially this one by Alex Selby, who says hes written his own specialist solver for one class of the Mc. Geoch and Wang benchmarks that significantly outperforms the software and D Wave machine tested by Mc. Geoch and Wang on those benchmarksand who provides the Python code so you can try it yourself. Also, Igor Vernik asked me to announce that on July 8th, D Wave will be giving a technical presentation at the International Superconducting Electronics Conference in Cambridge. See here for more info Ill be traveling then and wont be able to make it. I dont know whether the performance comparisons to Matthias Troyers and Alex Selbys code will be among the topics discussed, or if there will be an opportunity to ask questions about such things. In another exciting update, John Smolin and Graeme Smith posted a paper to the ar. Xiv tonight questioning even the signature of quantumness part of the latest D Wave claimsthe part that Id been 9. I relayed evidence that cast enormous doubt on the speedup part. Specifically, Smolin and Smith propose a classical model that they say can explain the bimodal pattern of success probabilities observed by the USC group as well as quantum annealing can. I havent yet had time to read their paper or form an opinion about it, but Id be very interested if others wanted to weigh in. Update May 2. The USC group has put out a new preprint responding to Smolin and Smith, offering additional evidence for quantum behavior in the D Wave device that they say cant be explained using Smolin and Smiths model. Free Mathematics Books list of freely available math textbooks, monographs, lecture notes, and other documents. It is just the same with mobile phones and cancer. In this country, one textbook Approved by the examining board uses this as an example of.