Category Archives: Uncategorized

Dumbing Down for Smartphones

Google changed its site ranking, if a site is not mobile friendly it will now be heavily penalized. I was quite fond of my old design but when running the Google Mobile test it failed miserably.  Hence a hasty redesign based on a newer WordPress theme was in order.

Screenshot 2015-04-20 01.43.20
Goodby my beloved theme, Google and that nasty smartphone killed you.

 

 

Je me souviens

Usually I don' t post anything political here.  This time I make an exception.  I hope it will remain the only one.

 

The Google-Martinis Chip Will Perform Quantum Annealing

Ever since the news that John M. Martinis will join Google to develop a chip based on the work that has been performed at UCSB, speculations abound as to what kind of quantum architecture this chip will implement.  According to this report, it is clear now that it will be adiabatic quantum computing:

But examining the D-Wave results led to the Google partnership. D-Wave uses a process called quantum annealing. Annealing translates the problem into a set of peaks and valleys, and uses a property called quantum tunneling to drill though the hills to find the lowest valley. The approach limits the device to solving certain kinds of optimization problems rather than being a generalized computer, but it could also speed up progress toward a commercial machine. Martinis was intrigued by what might be possible if the group combined some of the annealing in the D-Wave machine with his own group's advances in error correction and coherence time.
"There are some indications they're not going to get a quantum speed up, and there are some indications they are. It's still kind of an open question, but it's definitely an interesting question," Martinis said. "Looking at that, we decided it would be really interesting to start another hardware approach, looking at the quantum annealer but basing it on our fabrication technology, where we have qubits with very long memory times."

This leads to the next question: Will this Google chip be indeed similarly restricted to implementing the Ising model like D-Wave, or strive for more universal adiabatic quantum computation? The later has theoretically been shown to be computationally equivalent to gate based QC. It seems odd to just aim for a marginal improvement of the existing architecture as this article implicates.

At any rate, D-Wave may retain the lead in qubit numbers for the foreseeable future if it sticks to no, or less costly, error correction schemes (leaving it to the coders to create their own). It will be interesting to eventually compare which approach will offer more practical benefits.

So You Want to Learn About Quantum Computing?

"Students will learn by inhabiting an alternate history where Alan Turing and Richard Feynman meet during World War II and must invent quantum computers to defeat Nazi Germany. As a final project, they will get to program a D-Wave One machine and interpret its results."

If you are based in Seattle then you want to keep an eye out for when Paul Pham next teaches the Quantum Computing for Beginners course that follows the exciting narrative outlined above.

For everybody else, there is EdX's CS191x Quantum Mechanics and Quantum Computation course.  I very much hope this course will a be a regular offering.  Although it lacks the unique dramatic arche of P.Pham's story line this course is nevertheless thoroughly enjoyable.

When I signed up for this course, I didn't know what to expect.  Mostly, I decided to check it out because I was curious to see how the subject would be taught, and because I wanted to experience how well a web-based platform could support academic teaching.

This course fell during an extremely busy time, not only because of a large professional work load, but also because the deteriorating health of my father required me to fly twice from Toronto to my parents in Germany.  Despite this, the time required for this course proved to be entirely manageable.  If you have an advanced degree in math, physics or engineering, and want to learn about Quantum Computing, you shouldn't shy away from taking this course as long as you have an hour to spare each week.  It helps that you can accelerate the video lectures to 1 1/2 normal speed (although this made Prof. Umesh Vazirani sound a bit like he inhaled helium).

Prof. Vazirani is a very competent presenter, and you can tell that a lot of thought went into how to approach the subject, i.e. how to ease into the strangeness of Quantum Mechanics for those who are new to it. I was suspicious of the claim made at the outset, that the required mathematics would be introduced and developed as needed during the course, but it seems to me that this was executed quite well. (Having been already familiar with the required math, I don't really know if it'll work for somebody completely new to it, but it seems to me that indeed the only pre-requisite required was a familiarity with linear algebra).

It is interesting to see discussions posted by individuals who took the course and were apparently subjected to QM for the first time.  One such thread started this way:

"I got 100. It was really a fun. Did I understand anything? I would say I understood nothing."

To me this illuminates the fact that you simply cannot avoid the discussion of the interpretation of quantum mechanics.  Obviously this subject is still very contentious, and Prof. Vazirani touched on it when discussing the Bell inequalities in a very concise and easy to understand manner.  Yet, I think judging from the confusion of these 'straight A' students there needs to be more of it.  It is not enough to assert that Einstein probably would have reconsidered his stance if he knew about these results.  Yes, he would have given up on a conventional local hidden variable approach, but I am quite certain his preference would have then shifted to finding a topological non-local field theory.

Of course, there is only so much that can be covered given the course's duration. Other aspects there were missing: Quantum Error Correction, Topological and Adiabatic Quantum Computing and especially Quantum Annealing.  The latter was probably the most glaring omission, since this is the only technology in this space that is already commercially available.

Generally, I found that everything that was covered, was covered very well.  For instance, if you ever wondered how exactly Grover's and Shor's algorithms work, you will have learned this after taking the course. I especially found the homework assignments wonderful brain teasers that helped me take my mind off of more worrisome issues at hand.  I think I will miss them. They were comprised of well thought out exercises, and as with any science course, it is really the exercises that help you understand and learn the material.

On the other hand, the assignments and exams also highlighted the strengths and weaknesses of the technology underlying the courseware.  Generally, entering formulas worked fine, but sometimes the solver was acting up and it wasn't always entirely clear why (i.e. how many digits were required when giving a numerical answer, or certain algebraically equivalent terms were not recognized properly).  While this presented the occasional obstacle, on the upside you get the immediate gratification of instance feedback and a very nice progress tracking that allows you to see exactly how you are doing. The following is a screenshot of my final tally. The final fell during a week in which I was especially hard pressed for time, and so I slacked off, just guesstimating the last couple of answers (with mixed results).  In comparison to a conventional class, knowing exactly when you have already achieved a passing score via the tracking graph makes this a risk- and stress-free strategy.

Screen Shot 2013-04-27 at 11.56.31 AMA common criticism of online learning in comparison to the established ways of doing things is the missing classroom experience and interaction with the professor and teaching staff.  To counter this, discussion boards were linked to all assignments, and discussion of the taught material was encouraged.  Unfortunately, since my time was at a premium I couldn't participate as much as I would have liked, but I was positively surprised with how responsive the teaching assistants answered questions that were put to them (even over the weekends).

This is all the more impressive given the numbers of students that were enrolled in this course:

The geographic reach was no less impressive:

Having being sceptical going into this, I've since become a convert.  Just as Khan Academy is revolutionizing the K12 education, EdX and similar platforms like Cousera represent the future for academic teaching.

 

My Fringe Science Problem

Updated below.

Cold Fusion. It should have been that simple.

It is past time to come clean. I have an addiction problem. It is said that the best way to confront this is to admit it: No matter how hard I try, I cannot stop paying attention to fringe science.

Of course I could blame early childhood experiences. Back when I was a teen, about three decades ago, the free energy crowd was already quite active, "Tachyon energy" was then their favorite pseudo science to justify how their fantastic contraptions could work. One of the free energy bulletins that I read credited an electrical engineer who just happened to be a very distant relative of mine. So I managed to get in touch with him. He was indeed engaging in some far-fetched research, but it had nothing to do with free energy, and he had never heard of the people who misrepresented him (at the time, he was researching if common radar microwave radiation played any role in the forest die-off that was widely attributed to acid rain, and to that end built some strange test machinery).

This is a pattern that I've seen repeated many times since then. The approach generally seems to follow these steps:

  1. Find some far fetched fringe research.
  2. Claim some tremendous break-through and purport that just a little bit of additional research will result in a fantastic product.
  3. Based on this, collect investment money and then retire early after the R&D effort unfortunately doesn't work out.

The latest fringe science to receive this treatment is the text book example for pathological science, cold fusion. It has since been rebranded LENR for Low Energy Nuclear Reaction (it also goes by some other acronyms, but this seems to be the most common one).

One story that fits this pattern perfectly is that of the marvellous E-Cat (short for Energy Catalyzer). It sprang on the scene about two years ago with a tantalizing, if not independently supervised, demonstration that was convincing enough to bamboozle two Swedish physics profs into proclaiming that no chemical energy source could have the necessary energy density to produce the observed heat (conversion of water to steam). Over time this generated some mainstream news stories, and a bunch of blogs and forums sprung up to follow this story. One such blog followed an interesting trajectory: Paul Story, the maintainer of ecatnews.com, started out quite optimistic on this device, even banned some critical voices from the comment section of his blog. But then he was approached by the Australian billionaire Dick Smith who offered a prize of $1 million to anyone who could prove a usable 1KW LENR device. Nobody came forward to claim the money, although several commercial entities claimed to have just such prototypes. But this changed the tone at ecatnews.com and made it one of the few uncensored places where adherents and sceptics of this field could discuss (sometimes raucously) without the fear of being censored.

But Paul closed shop after he came to the conclusion that the E-Cat is just a scam. And this is where my addiction problem comes in. His blog was where I got my daily LENR dose, and the other blogs that still cover this story are by far less open and critical to be an adequate substitute. So in order to manage my addiction I have created a sub-blog, called Wavewatching Fringe Edition. This new addition is by no means supposed to take away the focus of this main blog, but rather help to manage my fringe science problem, and possibly serve as a resource to warn people to double check before investing in fringe science projects.

Be warned though, fringe science is addictive, it offers stories taller and more imaginative than any soap opera. If you want to stay clean, stay clear of the fringe.

Update

After losing a FB "Like" I feel like clarifying what I classify as "fringe science".  To have an objective criteria I lump everything into this category that doesn't flow from efforts published in reputable peer reviewed journals (creating new journals in order to get published doesn't qualify). Since everything performed by humans is far from infallible, peer review can miss interesting things, but the signal to noise ratio in the fringe category will be much higher.

Similar as with my "Lost Papers" section I will try to focus on aspects that maybe shouldn't be overlooked. But there is also the additional aspect that I focused on above. Old Hilbert papers make a very bad basis to solicite investments funds, on the other hand many of the hotter fringe science topics virtually spawn their own industries (that usually go nowhere).  If somebody researches these topics because they've been approached for investment funds then I hope the fringe section will paint a critical and realistic picture.

Of course it'll be great if something as controversial as LENR could get to the point were repeatable, scalable experiments with a proper theoretical under-pinning brings it back to physics' forefront.  Some LENR proponents feverishly believe that this is already the case.  Obviously I disagree, but I am not entirely ruling out that it could happen.

 

 

The Wave Particle Duality – A Deadly Divide

Wave_particle_duality_p_unknown
A particle and its associated wave function.

The curious fact that matter can exhibit wave-like properties (or should this rather be waves acting like particles?) is now referred to as the wave particle duality.  In old times it was often believed that there was some magic in giving something a name, and that it will take some of the christened's power. Here is to hoping that there may be some truth to this, as this obvious incompatibility has claimed at least one prominent life.

It was Einstein who first made this two-faced character of matter explicit when publishing on the photo electric effect, assigning particle-like characteristics to light that up to this point was firmly understood to be an electromagnetic wave phenomenon.

Particle is what particle does.But just like the question of the true nature of reality, the source of this dychotomy is almost as old as science itself, and arguably already inherent in the very idea of atomism as the other extrem of an all encompassing holism. The latter is often regarded as the philosophical consequence of Schroedinger's wave mechanics, since a wave phenomenon has no sharp and clear boundaries, and in this sense is often presented as connecting the entirety of the material world. Taken to the extreme, this holistic view finds its perfect expression in Everett's universal wavefunction (an interpretation happily  embraced by Quantum Hippies of all ages) which gave rise to the now quite popular many worlds interpretation of quantum mechanics.

While atomism proved to be extremely fruitful in the development of physics, it was never popular with religious authorities.  You can find echoes of this to this day if you look up this term at the Catholic Encyclopaedia:

Scholastic philosophy finds nothing in the scientific theory of atomism which it cannot harmonize with its principles, though it must reject the mechanical explanation, often proposed in the name of science, ...

Or at this site of religious physicists:

Atomism is incompatible with Judeo-Christian principles because atomism views matter as independent of God, ...

Religion of course really doesn't have a choice in the matter as it can hardly maintain doctrine without some holistic principle.  It is no coincidence that physics only progressed after the cultural revolution of the Renaissance loosened the church's dominance over the sheeple's  minds. But history never moves in a straight line.  For instance, with Romanticism the pendulum swung back with a vengeance. It was at the height of this period that Ludwig Boltzmann achieved the greatest scientific breakthrough of atomism when developing statistical mechanics as the proper foundation of thermodynamics. It was not received well. With James Clerk Maxwell having seemingly established a holistic ether that explained all radiation as a wave phenomenon, atomism had thoroughly fallen out of favour.  Boltzmann vigorously defended his work and was no stranger to polemic exchanges to make his point, yet he was beset by clinical depression and feared in the end that his life's work was for naught. He committed suicide while on a summer retreat that was supposed to help his ailing health.

He must have missed the significance of Einstein's publication on Brownian Motion just a year early.  It is the least famous of his Annus Mirabelis papers, but it lay the foundation for experimentalists to once and for all settle the debate in Boltzmann's favor, just a few years after his tragic death.

Thermodynamics made no sense to me before I learned statistical mechanics, and it is befitting that his most elegant equation for the entropy of a system graces the memorial at his grave site (the k denoting the Boltzmann constant).

A physicist can't ask for more to be remembered by than his most fundamental equation.
Ludwig Boltzmann Tombstone in Vienna.

Quantum Computing Hype Cycle and a Bet of my Own

box in troubleThe year 2013 started turbulent for the quantum computing field with a valiant effort by long time skeptic and distinguished experimentalist Michel  I. Dyakonov  to relegate it to the status of a pathological science akin to cold fusion (he does not use the term in his paper but later stated: "The terms 'failed, pathological' are not mine, but the general sense is correct.").

Scott Aaranson took on this paper in his unique style (it's a long read but well worth it). There really isn't much to add to his arguments, but there is another angle that intrigues my inner "armchair psychologist":  What exactly is it about this field that so provokes some physicists?  Is it that ...

  • ... Computer Scientists of all people are committing Quantum Mechanics?
  • ... these pesky IT nerds have the audacity to actually take the axioms of Quantum Mechanics so seriously as to regard them as a resource for computational engineering?
  • ... this rabble band of academics are breeding papers at a rabbit's pace, so that no one can possibly keep up and read them all?
  • ... quantum information science turned the ERP paradox on its head and transformed it into something potentially very useful?
  • ... this novel science sucks up all sorts of grant money?

The answer is probably all of the above, to some extent.  But this still doesn't feel quite right.  It seems to me the animosity goes deeper.  Fortunately, Kingsley Jones (whom I greatly admire) blogged about similar sentiments, but he is much more clear eyed on what is causing them.

It seems to me that the crux of this discomfort stems from the fact that many physicists have a long harbored discomfort with Quantum Mechanic's intractabilities, which were plastered over with the Copenhagen Interpretation (which caused all sorts of unintended side effects).  It's really a misnomer, it should have been called the ostrich interpretation, as its mantra was to ignore the inconstancies and to just shut-up and calculate. It is the distinct merit of Quantum Information science to have dragged this skeleton out of the closet and made it dance.

The quantum information scientists are agnostic on the various interpretations, and even joke about it.  Obviously, if you believe there is a truth to be found, there can be only one, but you first need to acknowledge the cognitive dissonance if there's to be any chance of making progress on this front. (My favorite QM interpretation has been suggested by Ulrich Mohrhoff, and I have yet to find the inspiration to blog about this in an manner that does it justice - ironically, where he thinks of it as an endpoint, I regard it as allowing for a fresh start).

Meanwhile, in the here and now, the first commercial quantum computing device the D‑Wave One has to overcome its own challenges (or being relegated to a computing curiosity akin to analog neural VLSI).  2013 will be the year to prove its merits in comparison to conventional hardware. I've been in touch with a distinguished academic in the field (not Scott A.) who is convinced that optimization on a single conventional CPU will always outperform the D-Wave machines - even on the next generation chip. So I proposed a bet, albeit not a monetary one: I will gladly ship a gallon of Maple sirup to him if he is proven right and our dark horse Canadian trail blazer don't make the finish line. The results should be unambiguous and will be based on published research, but just in case, if there should be any disagreement we will settle on Scott Aaronson as a mutually acceptable arbiter.  Scott is blissfully unaware of this, but as he is also the betting kind (the really big ones), I hope he'd be so kind as to help us sort this out if need be. After all, I figure, he will be following the D-Wave performance tests and at that time will already have formed an informed opinion on the matter.

The year 2013 started off with plenty of QIS drama and may very well turn out to be the crucial one to determine whether the field has crossed the rubicon.   It's going to be a fun one.

What’s in a Name

Thanks to Mad Men, the concept of brand equity has been widely popularized, the most prominent example being that of a dog food company's brand becoming toxic after it was reported that it used horse meat in its product (a practice that was outlawed in the US in 1970).

D-Wave is still in the early stages of building its brand, so the fact that some casual observers have very negative views, as apparent from some comments on my last entry, is worrying. Unbeknownst to me, Scott Aaronson put up a blog entry about the same time and I didn't immediately pick up on it as I was travelling.  Turns out, the large comment string points to a D-Wave 2007 event as the cause for this brand damage. At that time the expectations of the theoretical computer scientists collided head-on with the reality of D‑Wave.

The comment thread at Scott's blog is chock full of crazy, running the gamut from a poster accusing D-Wave of fraud to another one showering Scott with profanity. Always found it admirable that Scott doesn't censor such comments but lets them speak for themselves (although Joy Christian proved that his saintly patience is not inexhaustible).

Scott initially challenged D-Wave strongly after the 2007 event (long before I started to pay closer attention - I heard about the 16 qbit claim at the time but didn't consider such a chip yet commercially viable).  Recently he buried the hatchet, but of course for a theoretical computer scientist the question of what kind of complexity class a certain hardware design can address will remain in the forefront.

Fortunately Daniel Lidar who is currently studying a D-Wave machine reported in the comment section that he plans to soon publish on exactly that.  While other theorists such as Greg Kuperberg seem to be unwilling to move forward and past the 2007 "Sudoku crisis" (video of this "scandalous" demo can be found here), Scott and Daniel will clearly move this to a constructive debate based on published research.

The most prominent argument against this demo was that 16 qbits could not contain the entire parameter space of a Sudoku solution.  Of course this ignores how the D-Wave system is implemented, and that it works in conjunction with a classic system as a kind of quantum coprocessor.

The Sudoku solver is not currently given as a coding example on the D-Wave developer portal.  Since this old controversy can still cause damage to the company's brand I think it may be a good idea to include it there.

It's hard to gauge the extent of the brand damage that D-Wave suffered.  Most IT folks will probably not have heard of the company yet, so this mitigates the problem, but on the other hand this left its traces in Wikipedia. The latter will almost certainly be one of the first stops for anybody new to the subject when trying to form an opinion.  It is the first non-affiliated site that comes up in a Google search (when discounting recent news headlines) and it doesn't get better from there. The next search result is this outright defamatory article from the highly respect IEEE, an organisation that is supposed to be objective.

Although my professional life is mostly IT consulting, I had my share of high tech marketing challenges to deal with (for a while as BI software product manager).  In my experience a problem like this needs to be addressed heads on.  My advice would be to very openly embrace this old controversy and to position how and why D-Wave's design differs from universal gate-based quantum computing.  The company does that in various places of their web presence, but it took me 1o minutes of googling to find this old physicsandcake posting that addresses this nicely in simple terms. A potential customer coming across old and new misinformation should be able to very quickly find these kinds of counter arguments.

 

 

 

 

 

Strong words on Weak Measurements

Even the greatest ships can get it wrong.Recently news made the round that the Heisenberg Uncertainty principle was supposedly violated (apparently BBC online news tries to build on its bad track track record for news related to quantum mechanics).

Of course this is utter and complete nonsense, and the underlying papers are quite mundane. But all caveats get stripped out in the reporting until only the wrong sensational twist remains.

Yes, Heisenberg did at some point speculate that the uncertainty relationship may be due to the measurements disturbing the system that is probed, but this idea has long been relegated to the dust bin of science history, and Robert R. Tucci deservedly demolishes it.

I am now breathlessly awaiting the results of this crack team revisiting the Inquisition's test for witchcraft by attempted drowning.  I bet they'll find this doesn't hold up either. Cutting edge science.

 

 

Order from Quantum Discord

Have they no shame?
Even our children are already indoctrinated by popular Disney cartoons to think that Discord is bad. Borivoje Dakić et al. beg to differ.

Conventional hardware thrives on our ability to create precision structures in the micro domain.  Computers are highly ordered and usually (for good reason) regarded as perfectly deterministic in the way that they process information. After all, the error rate of the modern computer is astronomically low.

Even before the advent of quantum computing, it was discovered that this defining feature of our hardware can sometimes be a disadvantage i.e. randomized algorithms can sometimes outperform deterministic ones. Computers actually gain functionality by being able to use randomness as an information processing resource.

Due to their fundamentally probabilistic nature, randomness is always inherent in quantum computing designs. On the other hand, most quantum computing algorithms exploit one of the most fragile, ordered physical states: Entanglement, the peculiar quantum mechanical phenomenon that two systems can be entwined in a common quantum state. It is characterized by perfect correlation of spatially or temporally separated measurements.  The simplest protocol to exploit this feature is the quantum information channel, and it results in some quite surprising and, as is so often the case with quantum mechanics, counter-intuitive results. For instance, if two parties are connected via two very noisy directional channels with zero quantum information capacity, the participants will still be able to establish a qubit flow via entanglement distillation.

It has often been argued that entanglement is at the heart of quantum computing.  This credo has caused quite a bit of grief for the company D-Wave, that lays claim on shipping the first commercially available quantum computer. Although their erstwhile fiercest critic Scot Aaronson has made peace with them, he expressed that he still would like to see a measure for the degree of entanglement that they achieve on their chip.

Is it therefore quite surprising to see papers like this one recently published in Nature Physics that describe Quantum Discord as an optimal resource for quantum information processing. On first glance, some of this seems to be due to semantics.  For instance, John Preskill refers in his overview paper to all non-classical correlations as entanglement, but strictly speaking the term entanglement would never be applied to separable states. However, the paper demonstrates, theoretically as well as experimentally, that separable two qubit states with non-vanishing quantum discord can be found that offer better performance for their test case of quantum teleportation than a fully entangled state:

Experimentally achieved Remote State Preparation payoff for 58 distinct states of a Bloch sphere. Shown are the respective values for the two resource states $ \tilde{p}_w $(red) and $ \tilde{p}_B $ (blue). The dashed lines represent the theoretical expectations. There is a clear separation between the two resource states, which indicates that the separable state $ \tilde{p}_w $ is a better resource for RSP than the entangled state $ \tilde{p}_B $.

This raises the exciting prospect of a new approach to quantum computing that may not require the notoriously difficult preservation of entangled states,  giving hope that there may yet be a viable approach to quantum computing for the rest of us without requiring helium cooling infrastructure. Subsequently, quantum discord has become a research hot topic that spawned a dedicated site that helps keep track of the publications in this area.

At this point it is not obvious (at least to me) what impact these new insights on quantum discord will have in the long run, i.e. how do you develop algorithms to take advantage of this resource, and how will it, for instance, impact the channel capacity for quantum communication? (For a take on the latter see R.Tucci's latest papers).

What seems clear, though, is that D-Wave has one more good argument to stress the inherent quantumness of their device.

There is a really poorly produced video lecture available on this subject by a co-author of the Quantum Discord paper. (If only the presenter stopped moving so that the camera would not have to be constantly and noisily adjusted). Possibly the point of this dismal production value is to illustrate headache-inducing discord. In that case the University of Oxford certainly succeeded spectacularly.