A story of skepticism gone horribly wrong.
In 2008, researchers at HP Labs announced their discovery of the memristor, a type of electrical device that had been predicted by Leon Chua in a 1971 paper titled, “Memristor– the missing circuit element.” Memristors have been in the news again recently due to HP’s announcement of a bold new computing project called The Machine, which reportedly makes heavy use of memristor devices. Thanks to the sudden attention being paid to memristors in the past few years, we now know that they were with us all along, and you can even make one yourself with a few simple hardware items.
Since I teach my department’s introductory course on electronic devices, I’ve been studying memristors to see if it’s time to add them into the basic curriculum. During my reading, I started to notice a small percolation of skeptical voices. They appeared in popular science magazines, blog posts, and comment threads, and said some very unexpected things, like “HP didn’t really invent a memristor” and even “the memristor may be impossible as a really existing device.” I soon noticed that several of the critics were published researchers, and some of them had published their critiques on the arXiv, a preprint site used by credentialed researchers to post draft articles prior to peer review. The skeptics reached their peek in 2012, but fizzled out in 2013. One of those skeptics went out with a bang, crafting a bold conspiracy theory that still echoes in discussion fora and in the comment threads of tech industry articles. This post chronicles the rise and fall of his career as a memristor scholar. I also offer some speculation as to how the debacle could have been avoided.
The beginnings of memristor skepticism
There are a few non-peer reviewed articles in the arXiv that explain the technical details of memristor skepticism. The most commonly cited articles seem to one by Paul Meuffels and Rohit Soni, and another article by Blaise Mouttet. Of the two, Mouttet’s criticisms were the most scandalous: he claimed that the whole theory of memristance is wrong, and over time he developed a sprawling conspiracy theory to maintain this delusion. The real origin of this story happened in 2010, when Mouttet (then a Masters student at George Mason University) spoke at a special session of the International Symposium on Circuits and Systems (ISCAS). Up to that time, Mouttet had made some contributions to memristor research; he published a few articles at conferences, he had a serious article in the arXiv, and he was awarded some patents on memristor applications.
In order to speak at ISCAS, Mouttet would have submitted an article for peer review, and that article was evidently accepted. I’m able to access the article since I own the original proceedings distributed at the conference (Mouttet’s article has since been redacted). The article makes some cautious critical points about memristors, stated in an appropriate academic tone. But when Mouttet gave his presentation, he blew the lid off of those criticisms and upset a lot of people. His presentation was titled “The Mythology of the Memristor,” presented in the same session as some research from the HP team, who were evidently in the audience. Mouttet later posted his presentation online (I won’t link it here), but here are some of the things he said:
- He described HP’s invention as a “PR stunt that does not withstand scrutiny.”
- The memristor is not “fundamental,” if it is, then [paraphrasing] you can call anything “fundamental.”
- HP’s memristor wasn’t the first memristor-like device.
- HP’s memristor isn’t even a real memristor.
The presentation evidently didn’t go over well; Mouttet’s article was pulled from the conference proceedings, so you won’t find it in any library (that’s actually quite unusual, since articles are usually archived after they pass peer review). Mouttet complained of being blacklisted after the event, and there seems to be some truth to that. But Mouttet thought he was onto something. He thought he’s discovered a miscarriage of science, so he pressed the attack.
In 2012, Mouttet published his most critical article on the arXiv. Mouttet’s attack was answered by a Korean team led by Hyongsuk Kim, but Mouttet continued to press the attack with another article titled “The memristor and the scientific method.” This article was rejected from the ArXiv, and Mouttet was barred from future submissions… so he took his papers over to the viXra (that’s arXiv spelled backwards), a haven for quackery and pseudoscience. I’ve always been curious about the conditions that lead scholars into these dark corners of pseudoscience and conspiracy theory. (In fairness, back in 2010–2012 viXra might not yet have fully cultivated its reputation for pseudoscience.) Here’s what Mouttet said that got him relegated to the fringe:
Advancements in science are not made based on whether large corporations or famous scientists endorse a particular theory or idea. Science progresses solely based upon the formulation, testing, and modification of hypothesis. That is the scientific method.
Corporations have a profit motive and scientists, while typically portrayed as seekers of objective truth, can have their judgments clouded by a desire to enhance their reputations.
The “memristor” was originally proposed in 1971 by Leon Chua as a missing fourth fundamental circuit element linking magnetic flux and electric charge. In 2008 a group of scientists from HP led by Stan Williams claimed to have discovered this missing memristor. It is my position that HP’s “memristor” claim lacks any scientific merit.
If the HP researchers had developed a realistic model for resistive memory (whether it is called “memristor” or by some other name) it could be vetted by other researchers, compared to experimental data, and determined to be true or false. If necessary the model could be modified or corrected and an improved version of the model could be produced.
This is not what has happened.
The article tells a tantalizing story of a small group of researchers who lost sight of the scientific method; Mouttet was merely trying to set us all straight — except that Mouttet was wrong.
The claims of memristor skeptics
I took a close look at the issues raised by Mouttet and others (you can read my detailed thoughts on memristor theory on my Red Matrix channel). The most prominent attacks seem to conflate device physics (DP) with nonlinear electrical network theory (NENT). DP concerns itself with the fine details of particles, materials, junctions, surfaces, fields and their complex interactions. NENT, by contrast, is a more fundamental body of theory that describes conservation laws in electrical systems. Every device model has to obey conservation of mass, energy and charge; any DP model has to conform to the laws of NENT, and memristors belong to NENT. Indeed, Mouttet’s best counterexample — a “square law capacitor” — seems to violate conservation of energy and is therefore non-physical.
One of the particular points made by memristor skeptics is that memristance is based on flux linkage, which is usually understood to arise from magnetic fields. This problem seems to have vexed several serious memristor researchers: where is the magnetic flux in HP’s device? The answer appears to rest on the proper interpretation of flux linkage in NENT. In special cases like a wire loop inductor, flux linkage corresponds physically to magnetic flux. Apart from those special cases, there is not necessarily any connection between the two. This can seem puzzling at first, since many of us are trained to search for “physical interpretations” of abstract theoretical concepts.
So what is the physical interpretation of flux linkage, if it is not equivalent to magnetic flux? I would say that memristance itself provides the physical interpretation, in that it explains the range of behaviors allowed under physical conservation laws. Recent research points to a variety of mechanisms that exhibit memristive behavior; there may not be a simple “cartoon” explanation like we have for, say, capacitors, which are easily visualized as a volume in which electrical charge is stored. Perhaps given more time, we will arrive at more intuitive descriptions of memristive phenomena.
Growth of the conspiracy theory
By the time Mouttet migrated to viXra, he had already begun to nurse a conspiracy theory that mirrors some of the elements of climate change denial or anti-vaccine theory. We have wealthy corporations driven by a desire to protect their patents. We have a community of researchers who are motivated to protect their status. All of them collude together, pumping up the momentum of memristor theory for private unethical motives. In 2012, Mouttet wrote this:
Willliams [from HP] is making false claims about the memristor either out of his own ignorance or deliberate attempt at fraud to advance HP’s business agenda
It seems to me that there is a possibility that those who are invested in HP’s “memristor” may be inappropriately using their influence to suppress opposition to what could very well be the use of fraudulent science to support a corporate agenda.
…and in 2013 he wrote this:
Chua obviously has a self-serving incentive to claim all resistance switching devices are memristors. It seems to me incredible hypocrisy for Chua to claim this since he was arguing for 37 years that the memristor was a missing circuit element. Chua was certainly aware of the research being done in MRAM, ReRAM, and phase change memory but never claimed these memory types to be memristors until after HP’s initial claim.
Perhaps Chua may have more concern for his reputation than accurate science or consistency with his own definition?
The conspiracy theory began to acquire a small following. On the blog “Alpha Meme” at Science 2.0, Sascha Vongehr bought into the conspiracy and wrote this (emphasis added):
This “discovery” is simply a misinterpretation of devices that had been discovered many years before in India. Those original inventors did not misinterpret their work in order to make it into the news. Given the serious doubts that have been presented in many places, one seriously wonders whether the fact that the cheated are ‘just a bunch of Indians in India’ has anything to do with the embarrassing situation of that science media do almost not care. The latter though cannot explain that criticism is effectively censored.
Meanwhile, the popular science media took notice, and articles about the memristor debate appeared in outlets like Wired Magazine, New Scientist and others. This wave of press coverage gave them some attention, and probably explains why some skeptical comments still linger to the present day.
There has been some suggestion that Mouttet pumped up the conspiracy theory because he hired to do so by a competitor of HP. According to the New Scientist article, “Mouttet is hired by firms seeking to invalidate patents they feel are not novel and is writing his rebuttal. He fears that a broader definition could have a chilling effect on firms working on a range of memristor-like devices.” There are nevertheless strong indications that Mouttet was a true believer. In mid-2013, Mouttet took a permanent job outside the electronics industry, and has not had any subsequent involvement in memristor research. But he continued commenting on blogs and articles, advocating his conspiracy theory well after moving into a new line of work. Plus, in 2012 he wrote some things that seem very uncharacteristic of a patent troll or corporate shill (emphasis added):
It is not opinion it is logic. Chua and HP/Williams both have incentive based on financial motivations and reputation to continue this “fourth element” argument but it has no merit when analyzed objectively. I have no incentive to disagee with Chua and HP if they were right. In fact I was an early supporter of the memristor hype and was invited to speak at the first memristor and memristive systems symposium at UC Berkeley alongside Williams and Chua and at 2 IEEE conferences (ISCAS 2010, ICECS 2010). Even strong supporters of the memristor such as Pershin and DiVentra have rejected the “fourth element” interpretation in favor of generalized memristor, memcapacitor and meminductor models. In any case I am several decades younger than Williams and Chua and I can guarantee you I will have a hand in writing the history of the memristor long after Williams and Chua are dead. History will not be kind to them.
He sounds like a true believer to me, and regardless of his motives he has inspired a small cult following of fellow conspiracists.
Reflecting on the controversy
In academic circles, memristor skepticism seems to have fizzled out in 2013. When discussing this debacle with a few fellow researchers, we reflected on some aspects that might help navigate similar situations in the future. First, when young scholars like Mouttet think they may have found a big mistake in accepted science, what’s the appropriate way to address it with the community? Second, how can the academic community best respond to rehabilitate scholars who are headed in the wrong direction?
If nothing else, Mouttet’s early activities demonstrate that the community tolerates criticism in professional venues. His critical article was accepted to ISCAS, and he was allowed to post his thoughts on the ArXiv. He wasn’t censored. So where did he go wrong? Simple: he made direct personal insults and accusations of unethical conduct. Young scholars be warned: if you go around making accusations without solid proof, your career won’t last long. Honestly, a lot of young researchers entertain conspiratorial thoughts; keep those thoughts to yourself.
If you really think you’ve found a problem in the established science, the best thing you can do is frame your criticism as a question. Better yet, offer a positive alternative to the problem theory, so the community has something else to embrace. The memristor skeptics produced one really viable point, in the form of an open question that researchers could ponder: “where is the magnetic flux in the memristor?” This seems to have puzzled researchers enough that they paid attention and figured it out. You can always ask questions, but avoid jumping to premature conclusions (or express those conclusions with a heap of caution). Obviously, all scholars should be conscious of their own capacity for mistakes, so you need to dial back that confidence.
As to the community’s responsibility, it may have been possible to nip this fiasco in the bud through a bit of mentoring. Judging from Mouttet’s blog posts, he seemed completely in the dark as to why he was being blacklisted; as to why he offended the HP researchers at ISCAS. It’s not clear that he understood the expected etiquette, and he began to see himself as a persecuted defender of correct science. When looking over his papers, I noticed that he was the sole author on each of them; usually we would expect to see his academic adviser as a coauthor. I can only speculate as to Mouttet’s situation in the Masters’ program at GMU; it is not uncommon to see self-funded students who direct their own thesis work, and perhaps this describes Mouttet. If that’s the case, then he may have been working and publishing with little or no guidance or review from his faculty mentors. This definitely happens sometimes, and it is a plausible explanation for Mouttet’s lone descent into the fringe. Perhaps his adviser could have kept a closer watch; perhaps it wouldn’t have made any difference. In either case, this story is a reminder that even self-directed students represent their university when they present themselves in academic venues, and it would be wise to keep a close watch on them, lest they wander in unexpected directions.