Archive for the 'Technology' Category

Dec 04 2020

A Faraday Cage For Your WiFi

It can be amusing when there are multiple layers of fraud in a single scam, but it’s still a scam. With the holiday shopping season upon us, there are lots of products out there exploiting fear, pseudoscience, and scientific ignorance. The “Large WiFi Router Guard” now available from Amazon is a great example. Let’s unpack how silly this product is.

The seller claims that the router guard, “Blocks about 90% of the EMF large WiFi routers emit including the new 5G.” I’ll get to why some people think they should do this below, but first – let’s consider how nonsensical this very idea is. The entire point of a WiFi router is to take your internet signal and then broadcast it using electromagnetic frequencies in a radius that covers your home or office, typically 50-100 feet. If you need to cover a larger area you can use a repeater, which will pick up the signal and then boost it to extend the range. You can also use a mesh WiFi system which uses multiple devices to give larger and more consistent coverage.

The obvious problem with a WiFi router blocker is that you are blocking the essential function of the router – it can’t work if you are blocking the very signal it is designed to release. The product listing says that it can do this, “without affecting router network speed and performance,” which is impossible. I guess technically you can say that the router is still working, and you have not affected it directly, but you have effectively blocked its speed and performance outside the cage. If you are blocking 90% of the signal, you are blocking 90% of the performance.

As an aside, this product is essentially a small Faraday cage. In that respect, it does actual work in that it will block EMF. A Faraday cage is essentially an enclosure of continuous conducting material. Electrical fields will essentially distribute themselves around this outside conducting material, and those fields will tend to cancel out within cage. So if you are inside a perfect Faraday cage, you are protected from even intense electrical activity happening outside the cage. You can even touch the inside of the cage safely.

This is why, by the way, if you are in your car during a bad electrical storm, or when there is a downed power line nearby – stay in your car. It will act to some degree like a Faraday cage an can protect you.

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Nov 30 2020

AI Doctor’s Assistant

I have discussed often before how advances in artificial intelligence (AI) are already transforming our world, but are likely to do so much more in the future (even near term). I am interested in one particular application that I think does not get enough attention – using AI to support clinical decision-making. So I was happy to read that one such project will share in a grant from the UK government.

The grant of £20m will be shared among 15 UK universities working on various AI projects, but one of those projects is developing an AI doctor’s assistant. They called this the Turing Fellowship, after Alan Turing, who was one of the pioneers of machine intelligence. As the BBC reports:

The doctor’s assistant, or clinical colleague, is a project being led by Professor Aldo Faisal, of Imperial College London. It would be able to recommend medical interventions such as prescribing drugs or changing doses in a way that is understandable to decision makers, such as doctors.

This could help them make the best final decision on a course of action for a patient. This technology will use “reinforcement learning”, a form of machine learning that trains AI to make decisions.

This is great to hear, and should be among the highest priority in terms of developing such AI applications. In fact, it’s a bit disappointing that similar systems are not already in widespread use. There are several types of machine learning. At its core, machine learning involves looking for patterns in large sets of data. If the computer algorithm is being told what to look for, then that is supervised learning. If not, then it is unsupervised. If it’s using lots of trial and error, that is reinforcement learning. And if it is using deep neural networks, then it is also deep learning. In this case they are focusing on reinforcement learning, so the AI will make decisions, be given feedback, and then iterate its decision-making algorithm with each piece of data.

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Nov 20 2020

E-Mails and Energy Efficiency

Published by under Technology

It is a useful exercise to think about the way millions or even billions of people behave to look for low-hanging fruit in terms of increased energy efficiency or environmental sustainability. While this should be a purely evidence-based and cost vs benefit exercise, it has unfortunately been sucked into the ever-growing culture war (at least in the US). Plastic straws are a great example of this. We use them mostly by habit and culture. They are often given, for example, by default in restaurants. As a result an estimated 8.3 billion plastic straws pollute the beaches of the world. Most people don’t need or even want straws, so it is a simple change to make them on-demand, rather than automatic. Further, paper straw technology is sufficient to replace them with a more biodegradable option. We can argue about the best way to achieve the goal of limiting plastic straw waste, and whether outright bans are necessary, but the plastic straw has now become an icon on the right about overreach on the left. Ugh.

It’s possible that e-mail may follow the path of plastic straws into a senseless culture war. According to the BBC, the Financial Times reports that the UK government is considering recommending that everyone try to send fewer e-mails. Why? Climate change.

“It claimed that if every British person sent one fewer thank you email a day, it would save 16,433 tonnes of carbon a year, equivalent to tens of thousands of flights to Europe.”

That sounds like a lot of carbon, but of course it is tiny compared to total carbon output – about 0.0037% of the output of the UK economy. This illustrates a few principles worth pointing out. First, when hundreds of millions or billions of people engage even in a small behavior, the cumulative effect adds up. So shaving tiny costs (in resources, in pollution, etc.) can have a measurable effect. But obviously the effect is going to be proportional to the action. I probably look at a couple hundred e-mails per day. Not sending one “thank you” e-mail seems like a drop in the bucket – because it is. The result is that the absolute magnitude is large, because there are hundreds of  millions of buckets, but the relative magnitude is small.

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Nov 19 2020

Farming Mars

Published by under Technology

It is possible that sometime this century the first human will set foot on Mars. If this happens it is then likely that those humans that do will want to stay there for a while. It takes between 150-300 days to get to Mars with current technology (depending on launch and vehicle variables), unlike the three days it takes to get to the Moon. Perhaps before we try to get to Mars we will have nuclear thermal propulsion, and the trip time will decrease to about 90 days. So extended missions will likely be the norm, and in fact there is talk about a permanent colony on Mars. This will be a tremendous technological challenge, which is one reason I think we should do it. I also think this should be an international project.

One of the many challenges is resources – a colony will need energy, food, water, atmosphere, and protection from radiation. Energy might be the easiest to solve – just use the nuclear engine that got you there. Food, water, and oxygen will likely be the most challenging, as Mars is far away to supply. It’s likely that we will send robotic missions to Mars to pave the way for any human crew, pre-supplying the mission with everything they need. But if the ultimate goal is a Mars colony we will need to figure out how to make it self-sustaining, and this means growing food. Plants not only provide food, they also can provide oxygen to breath. You can grow food hydroponically, but this is limiting. It would be easier to support a colony with soil.

Scientists, therefore, are very interested in how well the regolith on Mars will serve as a substrate for farming. We don’t have direct access to Mars regolith to study, but we do have information about what the regolith is like from the various landers and rovers we have sent to Mars. We can therefore simulate Mars regolith, at least to some degree, and see if we can grow plants in it. There have already been studies doing just that. A 2019 study looked at seed germination and plant growth for 10 crops in Earth control soil, NASA simulated Moon regolith, and simulated Mars regolith. They found that 9/10 of the plants (all but the spinach) germinated and grew well in the simulated regolith, although not as well as  in the Earth soil. Of note, the simulated regolith in this study contained added organic material, to simulate the compost from previous crops or food.

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Nov 12 2020

Biden’s Climate Plan

Despite Trump’s attempt to break US democracy in order to alter reality to his liking, Joe Biden will be sworn in as the next president. This has obvious implications for US’s plans for tackling climate change. The first is that we will now have an executive branch that recognizes science, that climate change is real, and will actually try to do something about it. Immediately this means rejoining the Paris accord, and appointing people to the energy and environmental agencies that are not climate change-denying coal executives.

Biden’s plan (which is not the green dew deal) is to have our energy infractructure be net zero carbon emitting by 2035 and the entire country to be net zero by 2050. That is ambitious, and if I had to bet I would say we will fall short of this goal (although I hope I’m wrong), but it is a reasonable goal. How, theoretically, will we get there?

First, although it is politically risky to say so bluntly, we have to wean ourselves entirely off of fossil fuel. Biden acknowledged this during the second debate – end fossil fuel subsidies, and phase out fossil fuels over time. Given his stated goal, that would mean phasing out coal, oil, and gas by 2035. Is that even feasible? Currently, if we look only at power production, the mix of sources in the US is: fossil fuels 62.6%, Nuclear 19.6%, and renewables (wind, solar, biomass, geothermal, hydroelectric) 17.6%. The question is, in 2035, what do we want our energy mix to look like and how can we get there?

The path to getting there is not insignificant, because we will be emitting carbon along the way. One controversy is fracking and natural gas, which is cleaner than coal, but still a fossil fuel. Should we phase out coal quickly by replacing it with natural gas plants, or skip over natural gas and go straight to renewables and nuclear? If we could skip natural gas that would be optimal, but realistically the perfect may be the enemy of the good. Natural gas may be an effective temporary measure to quickly eliminate coal while we are transitioning to net zero energy production. But I am open on this question.

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Oct 29 2020

Brain-Machine Interface with Stentrode

Brain-Machine interface (BMI) technology continues to incrementally but steadily progress, and I do think this is one of the technologies that will transform our future. Studies have already demonstrated that there are no biological or theoretical limitations to such technology – the brain happily communicates with computers and seamlessly incorporates signals to and from them through the existing process of brain plasticity. The real limitation with practical applications of BMI is technological, mostly in designing electrodes that can safely work for a long time.

As I have discussed before, there are numerous approaches. Scalp surface electrodes are safe and easy, but have no resolution because the skull attenuates signals to and from the brain. Brain surface electrodes work much better, but they are invasive and tend to form scar tissue which can limit their lifespan. Microwires are a cutting edge approach, very thin hair-like wires that penetrate the brain, and can have both high resolution and long term safety. There is also the clever approach of putting the electrodes inside blood vessels in the brain. One company, Synchron, has been developing this technology since 2010 and their device, the Stentrode (a portmanteau of stent and electrode), has now completed a preliminary human trial.

The idea is to insert electrodes the way a stent would be placed inside a blood vessel to treat a blockage. The advantage here is that the endovascular stent technology already exists. They just had to make the stent out of electrodes, which they did. The huge advantage here is that you can get electrodes inside the skull and next to the brain without opening the skull or doing brain surgery. The brain itself is never penetrated. The electrodes are not as intimate with brain tissue as brain surface or penetrating electrodes, but that’s the tradeoff. The question is – how much efficacy can we get from endovascular electrodes?

Much of the research previously has been done on animals, mostly sheep and pigs. Initially the electrodes were connected directly to an external control device that also provides power. But this requires wires to go through the blood vessel to the outside, which is an infection risk. The latest design, the one studied recently, communicates wirelessly to a control box worn by the subject. The only mention I could find of how the electrodes are powered suggests they are powered wirelessly through this control box. This setup could potentially send and receive signals from the Stentrode.

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Oct 16 2020

Room Temperature Superconductor

Published by under Technology

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

Published by under Technology

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?

Published by under Technology

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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