Archive for the 'Technology' Category

Oct 16 2020

Room Temperature Superconductor

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Once again we have the reporting of a technological advance but leading with a bit of hype. The BBC headline is – “Superconductors: Material raises hope of energy revolution.” (Original article) I would first point out that I have been reading similar headlines since the 1980s. No revolution so far. We see some version of this claim every time there is an incremental advance in superconductor technology. We have hit a bit of a milestone with this latest progress, but it has to immediately be put into proper context.

Scientists have indeed demonstrated the first room temperature superconductor. But you know there’s a catch, right?

The scientists observed the superconducting behaviour in a carbonaceous sulphur hydride compound at a temperature of 15C.

However, the property only appeared at extremely high pressures of 267 billion pascals – about a million times higher than typical tyre pressure. This obviously limits its practical usefulness.

“Limits its practical usefulness” is perhaps a bit of typical British understatement. The way I see it they have just substituted one highly impractical limitation of superconducting material (extreme low temperatures) with another (extreme pressure). The research could have easily gone the other way. What if the high pressure superconductors were discovered first, then the holy grail would have been finding a superconductor at normal pressures, which they could have done by using extremely low temperatures. In fact, the low temperature may be the easier of the two.

At atmospheric pressure the record is still held by cuprates, which have demonstrated superconductivity at temperatures as high as 138 K (−135 °C).

It is easier to cool something to -135 °C then to put it under 267 billion pascals of pressure, so you might even argue we have taken a step backwards. This still might be useful if the research leads down a new path that ends with room temperature and atmospheric pressure superconductivity. Perhaps we’ll see in another 30 years.

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Oct 15 2020

Power From Graphene

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The headline reads, “Physicists build circuit that generates clean, limitless power from graphene.” There are some red flags there – my skeptical antenna always prick up when I see claims of limitless power. However, unlike the silly caricature of those who push back against appropriate skepticism, my doubts were the beginning of the process, not the end. I had many questions. How much power are we talking about? Where is the energy coming from (always a good question)? Does this require “free energy” or breaking any of the laws of thermodynamics? Is this theoretical or does it exist?

The press release, as is often the case, did not delve into these questions to a satisfactory degree, but was mainly hype. So I went to the original article –  Fluctuation-induced current from freestanding graphene. (Sorry, it’s behind a paywall, but I had access through my institution.) This helped, but was technically over my head in some parts. What I needed was to talk to an expert who could translate the technical bits for me. We discussed this news item, as much as we could, on the SGU and asked for help getting in touch with someone who could help unpack the physics at work here. Listener David Thompson, who is at the University of Arkansas where the research was done, was able to hook us up to the lead author of the study, Paul Thibado. We interviewed him yesterday for the show that will air this Saturday. Listen to the interview for all the details, but here is a quick breakdown.

The claim is that Thibado and his group have built a circuit that can harvest electrical energy from freestanding graphene. Graphene is a 2-dimensional material of carbon, think of a chickenwire with carbon atoms at each of the connection points. Graphene has interesting properties, and we are still near the beginning of exploring possible applications of this material. Freestanding graphene means the sheet is floating like a picture in a frame – this allows it to move freely. This sheet of graphene will undulate, buckle, and wave (like the surface of the ocean) due to background energy in a form a Brownian motion. The question Thibado and his group asked is this – can we harvest energy from the motion of the graphene, in the same way that you might harvest energy from the wind blowing or the sun shining? The answer, they found, is yes.

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Sep 14 2020

Who Invented the Lightbulb?

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The question of who should get credit for inventing the lightbulb is deceptively complex, and reveals several aspects of the history of science and technology worth revealing. Most people would probably answer the question – Thomas Edison. However, this is more than just overly simplistic. It is arguably wrong. This question has also become political, made so when presidential candidate Joe Biden claims that a black man invented the lightbulb, not Edison. This too is wrong, but is perhaps as correct as the claim that Edison was the inventor.

The question itself betrays an underlying assumption that is flawed, and so there is no one correct answer. Instead, we have to confront the underlying assumption – that one person or entity mostly or entirely invented the lightbulb. Rather, creating the lightbulb was an iterative process with many people involved and no clear objective demarcation line. However, there was a sort-of demarcation line – the first marketable lightbulb. That is really what people are referring to with Edison – not that he invented the lightbulb but that he brought the concept over the finish line to a marketable product.  Edison sort-of did that, and he does deserve credit for the tweak he did develop at Menlo Park.

The real story of the lightbulb begins in 1802 with Humphrey Davy He developed an electric arc lamp by connecting Volta’s electric pile (basically a battery) to charcoal electrodes. The electrodes made a bright arc of light, but it burned too bright for everyday use and burned out too quickly to be practical. But still, Davy gets credit as the first person to use electricity to generate light. Arc lamps of various designs were used for outdoor lighting, such as street light and lighthouses, and for stage lighting until fairly recently.

In 1841 Frederick de Moleyns received the first patent for a light bulb – a glass bulb with a vacuum containing platinum filaments. The bulb worked, but the platinum was expensive. Further, the technology for making vacuums inside bulbs was still not efficient. The glass also had a tendency to blacken, reducing the light emitted over time. So we are not commercially viable yet, but all the elements of a modern incandescent bulb are already there. The technology for evacuating bulbs without disturbing the filaments improved over time. In 1865, German chemist Hermann Sprengel developed the mercury vacuum pump, which was soon adopted by lightbulb inventors.

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Sep 10 2020

Miscibility Gaps Alloy Thermal Storage

I was recently sent this article about a new miscibility gaps alloy (MGA) thermal storage material. The technology is, perhaps, an incremental advance and may be useful for grid storage, but the article itself represents, in my opinion, horrible science communication. It seems like what you get when a general reporter, not trained in science journalism, reports on a complicated science topic. It didn’t give me any of the information I wanted, didn’t put this new technology into meaningful or accurate context, and didn’t explain some basic concepts involved.

Here is the basic story – a University of Newcastle (in Australia) team has developed an MGA material that could potentially be useful in grid storage by serving as a medium for thermal energy storage.  They also describe what an MGA material is by using an analogy to a chocolate chip cookie, where the chocolate chips melt when heated, storing most of the energy, but the rest of the cookie remains solid. That is about all the information you get from this article, stated in two sentences. The chocolate chip cookie analogy is fair, but following up with a slightly more technical definition would have been nice. MGAs are mixed materials where there is a range of temperatures (more specifically a region of the phase diagram that includes both pressure and temperature) where the different materials are in two or more phases. The rest of the article just states over and over again in different ways, like this is a new idea, why grid storage would be useful.

Why are MGAs particularly useful for thermal energy storage? First, the particles that melt store a lot of energy in the phase change while the particles that don’t melt can maintain the solidity of the overall material. But further, because of the liquid components, these materials have great thermal conductivity, so they don’t need infrastructure just to conduct the heat through the material. The Newcastle MGA is supposed to be an innovation because it is made from readily available material that is non-toxic.

I came away from the article with lots of important questions, all unanswered, and had to research them for myself. I was able to find information about MGAs in general, but not the Newcastle MGA specifically.

My first question, which you should ask about any proposed grid storage option, is – what is the round-trip efficiency? There are lots of grid storage options (which I review here), none of which are perfect. We need to know about each – what is the cost, how scalable are they, are they location-specific, what are the environmental effects, what are the energy losses over time, and what is the round-trip efficiency (the loss of energy from converting grid electricity to storage and then back to grid electricity). The best round trip efficiency is from pumped hydro, about 80-90%, but this is very limited by location and has serious environmental implications. Battery storage is not bad, at 60-70% round trip efficiency, but this is still an expensive option with lots of material waste and a limited lifespan.

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Aug 31 2020

Elon Musk Unveils Neuralink Pig

Three days ago Elon Musk revealed an update to his Neuralink project – a pig named Gertrude that had the latest version of the Neuralink implanted. (I first wrote about the Neuralink here.) The demonstration does not seem to involve anything that itself is new with brain-machine interfaces, but it does represent Musk bringing the state of the art together into a device that is designed to be commercial, rather than just a laboratory proof-of-concept.

Unfortunately, I have had to cobble together information from multiple sources. There does not appear to be a scientific paper with all the technical details spelled out, and the mainstream reporting is often vague on those details. But I think I have a clear picture now. The device is a coin-sized, 23 mm diameter and 8 mm thick. It was implanted “in” the skull, and also described as being “flush” with the skull. From this I take it that the device is not on top of or inside the skull, but literally replacing a small piece of skull. It has 3,000 super thin and flexible electrodes that connect to 1000 neurons. The device itself has 1024 channels (a channel reads the electrical difference between two electrodes).

The company also reports that it has an internal battery that can last “all day” and then recharge overnight. It also communicates to an external device (such as an app on your smartphone) via bluetooth with a range of 5-10 meters. As an electronic device, this is pretty standard, but it is good to have these features in a small implantable device.

The big question is – what can the Neuralink actually do? The demonstration, in this regard, was not that impressive (compared to the hype for Neuralink) – just the absolute bare minimum for such a device. It was implanted in a pig and was interfaced with neurons that connect to the snout. This demo device was read only; it could not send signals to the pig’s brain, only read from the brain. The demonstration consisted of Gertrude sniffing around her cage, and when she did so we could see signals from the neurons in her brain that were interfacing with the Neuralink.

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Aug 27 2020

Nuclear Diamond Batteries

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Articles are making the rounds on social media claiming a new battery technology that can make batteries that will last 28,000 years on a single charge. There is some truth to these claims, but they are mostly misleading. They make some unwarranted claims and leave out some critical context. This is likely mostly corporate self-promotion and fishing for investors, but what is the real science behind the claims?

Here is a typical quote form the popular press:

While they would be undeniably useful in EVs, their long life also makes them perfect for devices like pacemakers.

The company claims that its technology can be scaled up, and it could be used to make battery packs suitable for an electric car that lasts up to 90 years.

It is completely deniable that they would be useful in EVs, and I am always skeptical of claims that a technology can be “scaled up”. That should never be taken as a given, and is often the deal-killer with new technology. But let me review what these batteries actually are and then put the claims into context.

The concept was first introduced in the UK in 2016 – the idea is to encase nuclear waste in diamond so that the beta-decay of the waste interacts with the carbon in the diamond to generate a small electric current. The version being presented as a nuclear diamond battery (NDB) uses carbon-14 from graphite reactor rods as the source of beta decay. This represents a small percentage of the radioactivity of nuclear waste, 95% of which is the spent fuel itself, but the graphite waste is now also radioactive and there is a lot of it, about 250,000 tonnes world-wide.

The idea behind NDBs is that you make artificial diamond out of the carbon-14 from waste graphite from nuclear reactors. This would have the side benefit of taking care of some of the nuclear waste stream. Beta decay from the carbon-14 within the diamond would interact with other molecules causing the release of electrons and the generation of a small current. The entire thing could be encased in non-radioactive artificial diamond, which would prevent the escape of radiation and also protect it from damage.

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Aug 24 2020

A Controllable Metalens

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This is a (sort of) follow up to a previous post I wrote back in March about extreme depth-of-focus tiny flat nanolenses. The big ideas was that researchers are rapidly developing the technology to build a lens out of metamaterial that is structured on the nanoscale. Instead of using a large piece of curved glass to control light, these metalenses use the nanostructure on thin flat lenses. What impressed me at the time was the incredible potential applications of such tiny lenses, from cameras to medical applications. In fact, this tech was deemed one of the top ten emerging technologies in the 2019 World Economic Forum.

Now researchers have taken this technology one important step further – a method for possible dynamic control, meaning that these lenses can be focused and zoomed.

What the researchers did was infiltrate a metalens with “nematic liquid crystals”. This is the same technology used in liquid crystal displays – LCD monitors. They are basically transparent to translucent liquids that refract light like a lens. But the key with liquid crystals is that their properties can be modified by an external electric field (and also magnetically, thermally, or optically). They showed that they were able to “nontrivially” infiltrate the metalens with liquid crystals, and that this changed the optical properties of the metalens. They conclude:

By harnessing the tunability inherent in the orientation dependent refractive index of the infiltrated liquid crystal, the metalens system considered here has the potential to enable dynamic reconfigurability in metasurfaces.

In other words – they made the metalens tunable – this is a lens that cannot only be focused, but also can increase or decrease its magnification. In camera speak – this is a zoom lens. (“Telephoto lens” is a high magnification narrow focus lens, while a “zoom” lens can change its magnification.)

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Aug 18 2020

How Algorithms Affect Your Life

This is one of those things that futurists did not predict at all, but now seems obvious and unavoidable – the degree to which computer algorithms affect your life. It’s always hard to make negative statements, and they have to be qualified – but I am not aware of any pre-2000 science fiction or futurism that even discussed the role of social media algorithms or other informational algorithms on society and culture (as always, let me know if I’m missing something). But in a very short period of time they have become a major challenge for many societies. It also is now easy to imagine how computer algorithms will be a dominant topic in the future. People will likely debate their role, who controls them and who should control them, and what regulations, if any, should be put in place.

The worse outcome is if this doesn’t happen, meaning that people are not aware of the role of algorithms in their life and who controls them. That is essentially what is happening in China and other authoritarian nations. Social media algorithms are an authoritarian’s dream – they give them incredible power to control what people see, what information they get exposed to, and to some extent what they think. This is 1984 on steroids. Orwell imagined that in order to control what and how people think authoritarians would control language (double-plus good). Constrain language and you constrain thought. That was an interesting idea pre-web and pre-social media. Now computer algorithms can control the flow of information, and by extension what people know and think, seamlessly, invisibly, and powerfully to a scary degree.

Even in open democratic societies, however, the invisible hand of computer algorithms can wreak havoc. Social scientists studying this phenomenon are increasing sounding warning bells. A recent example is an anti-extremist group in the UK who now are warning, according to their research, that Facebook algorithms are actively promoting holocaust denial and other conspiracy theories. They found, unsurprisingly, that visitors to Facebook pages that deny the holocaust were then referred to other pages that also deny the holocaust. This in turn leads to other conspiracies that also refer to still other conspiracy content, and down the rabbit hole you go.

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Aug 17 2020

Adding Sound to AI

It has been fascinating, perhaps especially so as a neuroscientist, to watch the progress being made in artificial intelligence (AI), robotics, and brain-machine interface. Our understanding of biological intelligence is progressing in tandem with our attempts to replicate some of the functioning of that intelligence, as well as interface with it. Neuroscience and AI/robotics inform each other.

Here is another example of that – adding sound to the perception of an AI/robotic system to help it distinguish different objects. Before now AI object recognition has mostly been purely visual. (I always qualify these statements because I am not aware of every lab in the world that might be working on such things.) Visual object recognition is a good place to start, and this is what we probably think of when we imagine identifying an object ourselves – we look at it and compare it to our mental database of known objects. That is how our visual processing works.

But that is also not the whole story. We tend to underestimate, or simply not be aware of, the extent to which our brain are simultaneously processing multiple different sensory modalities to make sense of the world. When we listen to someone talk, for example, our brains also process the movement of their lips in order to make sense of the sounds as language (this is called the McGurk effect). When we identify someone else’s probable gender, we are strongly influenced by their voice.

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Aug 13 2020

Soft Tiny Robots

Published by under Technology

We are already living in the age of robots, but they are mostly hidden from our daily lives. Unless you have a job that entails interacting with a robot, the ones you see are mostly novelties, like Roombas, or the googly-eyed robots now wandering around some supermarkets.  Robots, however, are an iconic fixture of “the future”, and have been for the better part of a century.

The robots envisioned by the retro-sci-fi of the 1950s have not materialized, outside movies, but in the background robotic tech has been advancing significantly. We all love to watch the videos of running and jumping robots by Boston Dynamics. The tech is getting amazing. But so far they remain mostly for industrial use – a robot in every home still seems like a phenomenon of the future, not the present. In this video the creators show off their robot who can, for example, deliver boxes. That’s impressive, but why would you use such expensive advanced tech  (and risk having it jacked) to do something a human can easily and more cheaply do? Robots are great for manufacturing, and dangerous environments, but for everyday tasks they are not quite there – still too expensive to be worth it.

What about going in the opposite direction – small and squishy robots? We don’t even have to be talking about nanotechnology, not microscopic robots, just small ones. There are lots of tasks that could benefit from a swarm of small robots, but the challenge here is powering and controlling them. Advance is being made with this tech as well, but again we are not quite there, and still at the point where we cannot predict how long it will take before that “killer app” has arrived.

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