I like that he addresses that his main fear that, if D-Wave does <i>not</i> succeed after riding the marketing hype-machine, a "QC Winter" would likely happen, not unlike the "AI Winter" (<a href="http://en.wikipedia.org/wiki/AI_winter" rel="nofollow">http://en.wikipedia.org/wiki/AI_winter</a>) that occurred in the late 80's. The AI Winter was caused by a huge amount of over hyped claims and promises by the companies taking part which were never (and could never be) met, leading to the eventual collapse of the whole industry which is now only starting to see a practical recovery with the resurgence of Machine Learning.<p>D-Wave might be the belle of the ball today, but once the crowd turns, it could ruin an entire industry for a very long time. That's why skepticism is important when it comes to their claims.
For the ones that don't want to read the whole post, the <i>Truth</i> is that the 3600 speedup claimed in this article: <i>Commercial quantum computer leaves PC in the dust</i> [1](HN discussion: [2]) isn't worth much.<p>Quoting Scott Aaronson's post:
<i>As I said above, at the time McGeoch and Wang’s paper was released to the media [...] the “highly tuned implementation” of simulated annealing that they ask for had already been written and tested, and the result was that it outperformed the D-Wave machine on all instance sizes tested. In other words, their comparison to CPLEX had already been superseded by a much more informative comparison—one that gave the “opposite” result—before it ever became public. For obvious reasons, most press reports have simply ignored this fact.</i><p>[1] <a href="http://www.newscientist.com/article/dn23519-commercial-quantum-computer-leaves-pc-in-the-dust.html" rel="nofollow">http://www.newscientist.com/article/dn23519-commercial-quant...</a><p>[2] <a href="https://news.ycombinator.com/item?id=5697619" rel="nofollow">https://news.ycombinator.com/item?id=5697619</a>
Probably the biggest point to take away from the article is this:<p>> For years, I tirelessly repeated that D-Wave hadn’t even provided evidence that its qubits were entangled—and that, while you can have entanglement with no quantum speedup, you can’t possibly have a quantum speedup without at least the capacity to generate entanglement. Now, I’d say, D-Wave finally has cleared the evidence-for-entanglement bar—and, while they’re not the first to do so with superconducting qubits, they’re certainly the first to do so with so many superconducting qubits.<p>In other words, this is the first actual evidence that D-Wave even has the <i>potential</i> for quantum speedup.
It seems to me that all the hyperbole is about raised expectations. Hell, the fact they can even get something like this to work, and are able to determine (somewhat) that it is working the way they intended is enough to get me excited. I don't care if the QC they built performs faster or slower than a classical algorithm, because that stuff will simply come with time as we understand more about how QC works. With classical computers, we had several decades of knowledge about how electromagnetism worked - it was easily observable, and applying those principles to a complex switching system (already implemented by some mechanical computers at the time) was relatively straightforward, at least from a physical standpoint.
With QC, it seems to me (I don't really know more about than anyone else here) that we are making all sorts of theoretical discoveries as well as attempting to build a computer with those discoveries at the same time. So D-wave is basically the modern equivalent of Tesla and Turing, etc. all wrapped up into one big package. So the fact that this stuff is turning out not to be a complete fairytale is more than enough to get me excited.
A really long time ago when I was in grad school playing with genetic algorithms and simulated annealing, I implemented something that seems awfully similar to quantum adiabatic annealing. It worked as follows:<p>1. Assign all states of each variable equal probability.<p>2. Sample the living crap out of the search space with some sort of energy function for every possible configuration, scoring the discrete values of the variables of each individual sample by Boltzmann weighting of the energy function.<p>3. Every so often update the weights for selecting each variables potential values using the accumulated scores for each variable generated during step 2.<p>4. Repeat steps 2 through 3 until each variable converges to a single state.<p>I never published anything but I learned three things from this process.<p>1. It worked like gangbusters to find the space surrounding global optima of reasonably complex functions<p>2. It worked like crap to refine really good solutions into really great solutions.<p>3. It was horribly dependent on the underlying representation of the variables (i.e. if you mapped the input variables to a spin glass, it was just <i>awful</i>)<p>That and I suspect somebody already has a fancy name for exactly what I did back then...
While most of the recent popular coverage has been full of hype, Aaronson provides a concise summary of what's been going on before taking on the hype which appears to have left the poor man at his wit's end. Honestly I was rather confused also as the skepticism D-wave was met with at the beginning appears to have been replaced with a lot of hype without any mention of the actual physics of what's happening.<p>The position of most of the scientific community at the outset regarding D-Wave quantum computers was that it was uncertain what was going on at all. Nobody knew for sure if the D-Wave computers were really using quantum entanglement when they ran or not. Obviously a computer that does computations without doing at least some of the weird things allowed by quantum mechanics wouldn't be much of a quantum computer.<p>It appears that the D-Wave computers could indeed be taking advantage of entanglement. However since the D-Wave computers are not very isolated from their environment, the delicate effects they attempt to harness are sometimes disrupted when the computer interacts with its environment (aka decoherence to use the Quantum Mechanics term).<p>Overall it looks like D-Wave is making some progress on demonstrating their computer does really harness what's allowed by quantum mechanics. This is exciting, though ironically they have not caught up to their own overstated claims of what their machine does. Perhaps with more work they can better isolate their computer from it's environment and graduate from quantum annealing to reversible adiabatic quantum computing. Or maybe someone else working with some other physical system which has an intrinsically lower coupling to it's environment might beat them to it. An exciting time for the field nonetheless.<p>Getting a speed up on a particular class of problem could have a great deal of practical importance, but building a scalable computer that fully takes advantage of everything allowed by the laws of physics is the holy grail of quantum computing, and it doesn't look like D-Wave is there quite yet. Still an exciting time for the field nonetheless.
Aaronson is fabulous. In my opinion, possibly the best technical author around these days. If you haven't already, his new book[1] is absolutely worth checking out, especially if you're unfamiliar with quantum.<p>---<p>[1] : <a href="http://www.amazon.com/Quantum-Computing-since-Democritus-Aaronson/dp/0521199565/ref=sr_1_1?ie=UTF8&qid=1368734378&sr=8-1&keywords=scott+aaronson" rel="nofollow">http://www.amazon.com/Quantum-Computing-since-Democritus-Aar...</a>
I'm glad there are people who understand these things. I hope some day when the field of quantum computing congeals a bit more us mere mortals can begin to understand it as well.
Is there a SDK? I'd like to port a NES simulator.<p>(there is a conjecture that anything remotely able to do an addition will be used for emulating a Nintendo console)
PR departments have to release good publicity. Going too far is sleazy.<p>So is the recent D-Wave stuff just a combination of good PR and lazy journos, or are D-Wave being sleazy?<p>I guess it doesn't help that most people have no idea about quantum anything (let alone computing); or about massively parallel or P=NP etc.
Quantum computing reminds me of power from nuclear fusion: it's always 15 years away. I was awfully surprised when I read that D-Wave was already selling quantum computers. I'm glad that someone is willing to counter the hype. I find truth more interesting than fiction.
Important comment from Geordie on the dwave blog:<p>"It’s absolutely possible that adding active error correction might help at some point, maybe even in the next generation. If that is the case, we’ll certainly try anything anyone can think of to make the processors work better! In the specific case of exhibiting scaling differences over conventional algorithms, I’d bet we don’t need error correction (at least at the current snapshot) but at the next level (say 2000+ qubits) maybe we might. If we do, no problem — we’ll find a way!"<p><a href="http://dwave.wordpress.com/2013/05/08/first-ever-head-to-head-win-in-speed-for-a-quantum-computer/#comment-23435" rel="nofollow">http://dwave.wordpress.com/2013/05/08/first-ever-head-to-hea...</a>
This thing wasn't delivered by aliens. For $10m isn't there an instruction book that describes what it's supposed to do? Can't they take it apart and look inside it?