This is just a short update to include a link to the solver code developed by Matthias Troyer et al. that I discussed in my last blog post.
The advantage of conventional open source code is that everybody can play with it. To the extent that the code faithfully emulates quantum annealing of an Ising spin model, this will be a net benefit to D-Wave as it allows programmers to perform early testing of algorithmic concepts for their machine (similar to the emulator that is part of D-Wave’s evolving coding environment).
Matthias Troyer attached the source code to this earlier paper, and for easier download I put it into this zip file. As I am hard pressed for time these days, I didn’t get to work with it yet, but I confirmed that it compiles on my OS X machine (“make an_ss_ge_fi” produced a proper executable).
Meanwhile D-Wave continues to receive good press (h/tweb 238) as the evidence for substantial quantum effects (entanglement and tunneling) keep mounting, indicating that they can successfully keep decoherence at bay. (This older post on their corporate blog gives an excellent introduction to decoherence, illustrating how thermal noise gets in the way of quantum annealing).
On the other hand, despite enormous theoretical efforts, it is yet not decisively shown what quantum resources are required for the elusive quantum speed-up, but this recent paper in Nature (arxiv link) claims to have made some substantial headway in isolating some of the necessary ingredients (h/t Theo).
While this is all quite fascinating in the academic sense, at this time I nevertheless regard quantum speed-up as overrated from a practical point of view. Once I manage to set some time aside I will try to explain in my next blog post why I don’t think that this has any bearing on D-Wave’s value proposition. There’s no place in the multiverse for the snarky, dark movie script that Robert Tucci offered up the other day 🙂
The conditions were straightforward, can the D-Wave machine beat a single classical CPU? But of course we specified things a bit more precisely.
The benchmark used is the time to find the ground state with 99% probability, and then not only the median is considered but also the 90%, 95% and 99% quantile. We then agreed on basing the bet on the 90% quantile. I.e. the test needs to run long enough to make sure that for 90% or more of the instances we find a ground state with 99%.
Assuming that Matthias gets to conduct his testing on the current and next chip generation of D-Wave, we agreed to make this a two part bet, i.e. same betting conditions for each.
Unfortunately, I have to concede the first round. The D-Wave One more or less tied the classical machine, although there were some problem instances where it was doing better. So the following jars of Maple Syrup will soon be shipped to Zürich:
Not the most exquisite or expansive maple syrup, but 100% pure, and Canadian. The same kind I use at home, and I figure the plastic jars will tolerate shipping much better than glass.
What I was obviously hoping for was a decisively clear performance advantage, but at this point this isn’t the case, unless you compare it to off-the-shelf optimizer software as was done in the test conducted by McGeoch et. al.
So will I ever get some Raclette cheese in return for my Maple syrup? The chances for winning the next part of my bet with Matthias hinge on the scaling behavior, as well as on the question if a class of hard problems can be identified where quantum annealing manages to find the ground state significantly faster. For the generic randomly generated problem set, scaling alone does not seem to cut it (although more data will be needed to be sure). So I am counting on D‑Wave’s ingenuity, as well as those bright minds who now get to work hands-on with the machine.
Nevertheless, Matthias is confident he’ll win the bet even at 2000 qubits. He thinks D-Wave will have to improve much more than just the calibration to outperform a single classic CPU. On the other hand, when I had the pleasure of meeting him last year in Waterloo, he readily acknowledged that it was impressive what the company had accomplished so far. After all, this is an architecture that was created within just ten years based on a shoestring budget, compared to the multimbillion dollar, decades mature semiconductor industry.
Unfortunately, when his university, the venerated ETH Zürich (possibly the best engineering school on this planet) came out with this press release, they nevertheless (accidentally?) played into the old canard that D-Wave falsely claimed to have produced a universal quantum computer.
It puts into context the Chinese whisper process as depicted in this cartoon that I put up in an earlier post. Unlike depicted here, where the press gets most of the blame, ever since I started paying attention to university press releases, I am compelled to notice that they are more often than not the true starting point of the distortions.
For anybody needing an immediate dose of D-Wave news, Wired has this long, well researched article (Robert R. Tucci summarized it in visual form on his blog). It strikes a pretty objective tone, yet I find the uncritical acceptance of Scott Aaronson’s definition of quantum productivity a bit odd. As a theorist, Scott is only interested in quantum speed-up. That kind of tunnel vision is not inappropriate for his line of work, just an occupational hazard that goes with the job, but it doesn’t make for a complete picture.
Other than that, the article only has some typical minor problems with QM.
At this point, you don’t really expect a journalist to get across how gate model quantum algorithms work, and the article actually does this better than most. But the following bit is rather revealing; The writer, Clive Thompson, describes visually inspecting the D-Wave chip:
Peering in closely, I can just make out the chips, each about 3 millimeters square. The niobium wire for each qubit is only 2 microns wide, but it’s 700 microns long. If you squint very closely you can spot one: a piece of the quantum world, visible to the naked eye.
SQUIDs for magnetometers don’t have to be very small. (Photo approximately to scale – as indicated by the handwriting on this lab sample). This is because for this application you want to measure the magnetic flux encompassed by the loop.
Innocuous enough quote, and most physicists wouldn’t find anything wrong with it either, but therein lies the rub. SQUIDs can be fairly large (see photo to the right).
Any superconducting coil can harbour a coherent quantum state, and they can be huge.
The idea that quantum mechanics somehow only governs the microcosm has been with us from its inception, because that’s what was experimentally accessible at the time i.e. atomic spectra. But it is a completely outdated notion.
This is something I only fully came to grasp after reading Carvar Maed’s brilliant little book on Collective Electrodynamics. In it, he makes a very compelling case that we are due for another paradigm change. To me, the latter means dusting off some of Schrödinger’s original wave mechanics ideas. If we were to describe a simple quantum algorithm using that picture, there’s a much better chance to give non-physicists an idea of how these computation schemes work.
It has been my long held belief that science media needs an additional corrective in the form of blogs, similar to the development we’ve seen in the political sphere. Now it seems the news that the BICEP results, that were heralded as Nobel price worthy, may be wrong, originated with this blog post.
Certainly big enough news to interrupt my blog hiatus.
Maybe sometimes some results are really too good to be true, and this may turn out to be this year’s version of the faster than light neutrinos.
It also illustrates that science is a bit like sausages, sometimes you don’t really want to know exactly what went into it. At least that how I felt when I learned that the source for this controversy is the way that data has been scrapped from a PDF copy. One could hardly make a better case for why we need a good Open Science infrastructure.
Irrespective my favorite physics blogger took on the results and puts them into context.
The Canadian Revenue Agency is the equivalent to the IRS down South. They owe me money and always make me work to get it.
Unlike the US, tax returns in Canada are due by the end of April, but because of the Heartbleed bug, Revenue Canada had to take down electronic filing for a while, so the deadline has been extended a bit. It seems I may need the extra days as life is keeping me extraordinarily busy. Saturday morning is usually my blogging time, but this weekend I had to look after my kids (my wife Sara was performing Beethoven 9th with the Peterborough Symphony) and today my oldest daughter turned seven, filling the day with Zoo visits and birthday cakes.
At least the bug bought me some more time.
So in order to not completely abandon this blog, a couple of links to other outstanding science musing are in order. To that end I would like to highlight some posts of Sabine Hossenfelder, a blogging physicist professor of theoretical physics currently teaching in Sweden. Her most recent post discusses some of the structural problems in Academia, which in reality is nothing like the commonly held notion of a utopian ivory tower (rather, the tower stands and becomes ever more compartmentalized, but there is nothing utopian about it).
Her post on the Problem of Now makes a nice primer for a long-planned future post of mine on Julian Barbour’s End of Time, because arguably he took “Einstein’s Blunder” and ran with it as far as one can take it. The man’s biography also ties back to the dilemma of academia, as it really doesn’t allow much space for such deep, and out of the mainstream, research programs.
And I probably should mention that Sabine also knows how to sing. It obviously takes a physicist to really muster the emotional impact of the agonizing ongoing demise of SUSY.
Are You a BDeliever? Science and religion have a difficult relationship, and sometimes they combine in the most obscure manner, such as when Scientology was conceived. The latter seems to have lost a lot of its appeal and followers, but it seems that another new religion is poised to grab the mantle.
That is, if one is willing to follow Scott Aaronson’s rationale that believing in the achievability of significant speed-up with D-Wave’s architecture is a matter of faith. Ironically Scott, who is teaching computer science at MIT, made this comment about the same time that the MIT Technology Review named D-Wave to its Top 50 Smartest Companies list. An illustrious selection, that any company would be delighted to be included in. The only quibble I have with this list is that it ranks Elon Musk’sSpaceX before D-Wave, my point being that quantum mechanics is harder than rocket science. After all, with the latter, everybody can decide if your spacecraft made it into orbit or not (classical mechanics is so straightforward). On the other hand, we still have the ongoing high profile battle over the question of how quantum D-Wave’s machine actually is (since Schroedinger the uncertainty of what’s in a box seems to be a constant in Quantum Mechanics).
“What I think is going on here is that they didn’t model the ‘noise’ correctly. (….) One should have a little more respect with the truth.”
In academic parlance these are fighting words. And so the show goes on.
But I want to take a break from this for a moment, and focus on another question: How did a startup like D-Wave get to this point? Time magazine front page material, coverage in the New York Times, being named in the same breath as SpaceX. From a business perspective this is nothing but an amazing success story to have gotten to this point. And to me, the question of what makes successful entrepreneurship is of no less interest than science and technology.
Geordie got closer to having a shot at Olympic gold than most of us, having been an alternate on the Canadian wrestling team at the 1996 Olympic Games, so getting this one may have been bitter sweet.
Flying into Vancouver I imagined Geordie Rose to be a Steve Jobs-like character, about whom it was famously quipped that he was surrounded by his own reality distortion field, an invisible force that made others see the world like he did, and made them buy into his vision. And although I never had the pleasure of meeting Steve Jobs, I think it is safe to say that Geordie is nothing like him. If I had to describe him in one word, I’d say he is quintessentially “Canadian”, in terms of the positive attributes that we typically like to associate with our national character. (Full disclaimer: Technically I am not Canadian yet, just a permanent resident).
Given the amazing success that D-Wave has had, and the awards and accolades that he himself has received, I was impressed with his unassuming demeanor. Hard to imagine Geordie would ever park his car in a handicap spot, as Jobs was fond of doing, to shave a couple minutes off his commute.
D-Wave just moved to a new enlarged premises. In their old building Geordie occupied an interior office without windows. I naturally assumed that he would have upgraded that. So I was surprised to learn that his new workspace still doesn’t have any windows. His explanation was simple, it allows him to be close to his team.
My take away is that visionaries cannot be pigeon-holed, because when talking to Geordie it was quickly obvious that his focus and dedication to making his vision a reality is ironclad, and his excitement is infectious. So this is one key similarity to Steve Jobs after all, and then there is of course this, which goes without saying:
Great entrepreneurs never do it for the money.
Prof. Vazirani must have picked up on D-Wave’s commitment to make Quantum Computing work, as the New York Times also quotes him as saying about D‑Wave that “after talking with them I feel a lot better about them. They are working hard to prove quantum computing.”
That Geordie picked an approach which is so abhorred by theorists, I attribute to yet another aspect that, in my mind, marks great entrepreneurship: An almost ruthless pragmatism. Focusing on the less proven quantum annealing on a chip, he managed in just seven years to turn out an entirely new computing platform. Meanwhile, the advances in superconducting foundry know-how that his company ushered in, will also benefit other approaches, such as the gate based implementation that UCSB’s John Martinis plans to scale up to 1000 qubits within five years.
To me, there is no doubt that the hurry to get something to the market is a net benefit to the entire quantum computing field, as I expect it will attract more private capital. And that is because Quantum Computing is now no longer perceived as something nebulous, something that just may happen 25 years down the road.
Game changers polarize. So if we pay heed to Scott Aaronson’s rhetorics Geordie clearly has a leg up over Steve Jobs. Where the latter had a cult following, Geordie’s on his way to having his own religion. Maybe that’ll explain the following recent exchange on D-Wave’s blog:
(h/t Rolf D. and commenter Copenhagen for pointing me to material for this post.)
Cosmology is quintessential popular science, but I always regarded it as the most dismal field of physics because there is no avenue for experiments to keep run-away speculations at bay. It’s like trying to catch a perpetrator by staring at a multi-billion year old crime scene with the evidence all scattered. And of course, since it deals with the beginning of time, scientists may have a hard time divorcing themselves from philosophical or religious beliefs (e.g. for a long time, Einstein presumably regarded the big bang theory as an invention by the clergy).
Given the ad-hoc nature of the cosmic inflation theory to fix problems with the big bang explanation, I always felt rather lukewarm about it. It just appeared too much like a convenient quick fix. But I am certainly warming up to it, given that the new detailed observations of the cosmic microwave radiation do fit the picture quite nicely. This radiation is essentially a convenient thermometer for the entire universe, as it can be regarded as thermal black body radiation. This is as close as we can get to the aforementioned primordial crime scene, taking advantage of the fact that the further we look into space, the earlier the events we observe. If the mainstream big bang theory is correct, then the evidence for it must be splattered all over space encoded in this background radiation.
Brian Dodson (one of the finest pop science writers on the web) nicely explains why this data is such a treasure trove. I have little to add to his article other than the caveat that one should keep an open mind, that the evidence may yet still fit a completely different sequence of events (e.g. this one made some recent headlines, and it will be interesting to observe how such alternative models may be adapted to fit the newly released data).
And then there is, of course, the other raison d’etre of this blog, pointing out when popular science writing gets the details wrong. The better outlets, such as the NYT, got it right when they wrote that this data offers the first direct evidence for gravitational waves as predicted by general relativity. And a layman certainly can relate to this, simply by appreciating the released pictures, that almost look like ripples left in the sand by some ocean waves.
Slight temperature fluctuations, indicated by variations in color, of the cosmic microwave background of a small patch of sky (as provided by the BICEP2 Collaboration).
Just as accelerated electrical charges will under most circumstances emanate EM radiation, accelerated masses will send out gravitational waves, carrying away some of the kinetic energy of the system.
Of course, gravitational waves have the huge advantage of being the kind of physics accessible to immediate measurement, and this new cosmological evidence gives credence to the persistence in pushing for better gravitational wave detectors to eventually measure these waves directly.
As life keeps me otherwise busy, I am again late in finishing my next blog post, but in the meantime this web comic nicely summarizes much of the news dynamics of science in general and quantum computing in particular (h/t my lovely wife Sara).
Last year I tried to establish a blog tradition of starting the new year with a hopeful science news item, something that shows enormous technological potential to change the world for the better. But come New Years, it didn’t work out, the Quantum Computing and D-Wave news was simply moving too fast, and I also didn’t come across anything that felt significant enough.
Not any more. Recently a breakthrough discovery has been made that has the potential to rival the impact of the ammonium synthesis. When Fritz Haber discovered this process in the early 20th century, he single-handily vanquished famines from the developed world as subsequently fertilizer became an inexpensive commodity. This new discovery has the potential to do the same for thirst and droughts. It involves a surprising property of graphene and does justice to the hype that this miracle-material receives: Although graphene is usually hydrophobic it can be made to form capillaries that efficiently absorb water. Now researchers at the University of Manchester report having formed layers of graphene oxide that exploit this property to make efficient water filters on the molecular level.
These filters are reported to work astoundingly efficiently, keeping anything out above the size of nine Angstrom (9.0 × 10-10 m) at a speed comparable to an ordinary coffee filter. It is essentially sieving on the molecular level. This is not yet enough to remove ordinary sea salt, but the scientists, who just published their research in last week’s issue of Science, are confident that the material can be scaled down to this level.
If so, it will change the world. Desalination of sea water is currently only affordable to the wealthiest countries, as the required investments are staggering, and operating the necessary infrastructure is very energy intensive. For instance, Saudi Arabia recently commissioned the world’s largest desalination plant for US$ 1.46 billion. The scope of the project is impressive, yet this amount of money will still only suffice to supply one large city metropolis with enough water (~3.5M people).
According to a new report by the Worldwatch Institute, 1.2 billion people, or nearly a fifth of the world’s population, live in areas of physical water scarcity, i.e. places where there is simply not enough water to meet demand. Another 1.6 billion face economic water scarcity, where people do not have the financial means to access existing water sources. If this research succeeds in creating a material that can simply filter out sea salt, and if its production can be scaled up, then this scourge on humankind could be rapidly diminished.
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).
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’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.
. In it, he makes a very compelling case that we are due for another paradigm change. To me, the latter means dusting off some of 
, Robert R. Tucci