May 13 2021

Communicating Through Handwriting with Thought

We have another incremental advance with brain-machine interface technology, and one with practical applications. A recent study (by Krishna Shenoy, a Howard Hughes Medical Institute investigator at Stanford University and colleagues) demonstrated communication with thought alone at a rate of 15 words (90 characters) per minute, which is the fastest to date. This is also about as fast as the average person texts on their phone, and so is a reasonably practical speed for routine communication.

I have been following this technology here for year. The idea is to connect electrodes to the brain, either on the scalp, on the brain surface, inside blood vessels close to the brain, or even deep inside the brain, in order to read electrical signals generated by brain activity. Computer software then reads these signals and learns to interpret them. The subject also undergoes a training period where they learn to control their thoughts in such a way as to control something connected to their brain’s output. This could mean moving a cursor on a computer screen, or controlling a robotic arm.

Researchers are still working out the basics of this technology, both hardware and software, but are making good steady progress. There doesn’t appear to be any inherent biological limitation here, only a technological limitation, so progress should be, and has been, steady.

The researchers did something very clever. The goal is to facilitate communication with those who are paralyzed to the point that they cannot communicate physically. One method is to control a cursor and move it to letters on a screen in order to type out words. This works, but is slow. Ideally, we would simply read words directly from the language cortex – the subject thinks words and they appear on a screen or are spoken by a synthesizer. This, however, is extremely difficult because the language cortex does not have any obvious physical organization that relates to words or their meaning. Further, this would take a high level of discrimination, meaning that it would requires lots of small electrodes in contact with the brain.

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May 11 2021

Magnets and Fusion

Technology is often interdependent. Electric cars are dependent on battery technology. Tall skyscrapers were not possible without the elevator. Modern rocketry requires computer technology. And the promise of fusion reactors is largely dependent on our ability to make really powerful magnets. Recent progress in powerful magnet technology may be moving us closer to the reality of commercial fusion.

Fusion is the process that powers stars. Stars, like our sun, start out as mostly hydrogen. Their intense gravity will squeeze that hydrogen gas into a dense ball, causing the hydrogen to heat up to millions of degrees – 15 million degrees C. At this temperature the hydrogen is stripped of its electrons, forming a state of matter known as plasma. In fact, most of the normal matter in the universe is in the plasma phase. A hydrogen nucleus is basically a proton, which has a positive charge. Like charges repel, so all those positive protons are trying to push each other apart. This is overcome by the power of gravity. If the ball of hydrogen is massive enough then the core will be compact enough that the hydrogen ions will be fused together into helium. This process releases a tremendous amount of energy and heat, which further pushes the star outward. Stars then reach an equilibrium point where the outward pressure of fusion and magnetic repulsion balances the inward force of gravity. When enough helium builds up in the core, the hydrogen in the outer layers of the core is no longer dense enough to fuse, so the star collapses until the pressure is great enough to fuse the helium together. This keeps happening, depending on the mass of the star (it has to be massive enough to fuse the heavier elements) until the most massive stars get to iron in their core. Iron does not produce energy when it is fused, so it cannot act as fuel to keep the star going. The core will then collapse and result in a supernova.

Scientists are trying to reproduce the fusion of hydrogen into helium on the Earth. We have already done this in one-off explosive events, called hydrogen bombs. But we want to do this in a steady controlled fashion in order to access all that heat energy to drive turbines and generate electricity. This has been a project for decades, and despite steady progress never seems to get closer (like running down a hall in a horror movie with the camera effect that makes it look like you are making no progress). But once again we are being told that this time they really mean it and we are getting close.

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May 10 2021

Sequestering Carbon

The climate and environment are always changing, but this statement is not that meaningful unless you put it into the perspective of timescale. Over very short timescales, a few years, climate is extremely stable. Over very long timescales, millions of years, climate can change dramatically, turning lush rainforests into deserts. Over hundreds of years the climate has been relatively stable, except for natural oscillating cycles. Climate can even be relatively stable over thousands of years, but at this scale we do start to get into the bigger ice-age and glaciation cycles.

On this backdrop we have the anomalous forcing of global average temperature increases over the last 150 years that cannot be explained as part of any natural cycle. This does correlate with the release into the environment of free carbon dioxide, the carbon component of which had been previously sequestered for millions of years in the form of fossil fuels. Obviously we are in the midst of a big conversation about how to reduce the industrial release of more carbon to limit effects on the environment. While sincere efforts are being made, the pessimistic view is that we simply lack the political will to do what needs to be done, and there are too many economically vested interests in the cheap energy provided by fossil fuel. We will eventually convert to cheaper and cleaner renewable energy sources, because market forces are moving in that direction, but probably not before we burn through our entire “carbon budget”.

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May 07 2021

COVID Vaccines Are Safe and Effective

We are at a critical point in this pandemic. Worldwide the pandemic is actually more active now than ever. There have been over 156 million cases, and the world is seeing almost 800k new cases a day. The recent peak is mainly due to India, but infections continue throughout the world. The high number of cases also increases the risk of new variants emerging. India also shows us how quickly medical resources can be overwhelmed with catastrophic results. They ran out of oxygen – which is critical to keeping severe COVID patients alive.

Yet, with each wave there was the prevailing sense that this was the worst we’ll get, and now we are rounding the corner. So far, this has been wrong every time. Of course this pandemic must end eventually, the question has always been how much death, morbidity, and economic damage would it cause in the meantime. The primary reason for the next worse wave of the pandemic has largely been that people eased off on pandemic protocols. They stopped wearing masks and social distancing and started gathering in large groups. And each time the virus made us pay for it.

But now, despite being in the middle of the biggest wave so far, the situation is changing, because now we have multiple safe and effective vaccines. In the US there are two mRNA vaccines, from Moderna and Pfizer-BioNTech, in addition to the J&J vaccine. Other than a minor hiccup with extremely rare blood clots, these vaccines have a great safety profile. In states with high vaccine uptake the virus is getting under control, and restrictions are starting to be safely lifted. Life is partly getting back to normal – thanks entirely to the vaccines.

But we are facing two problem – entirely of our own making. The first is that we are in a race against time. We have to vaccinate enough of the world to achieve herd immunity before new variants emerge that are resistant to the vaccines. Also, we don’t know how long immunity from the vaccines last, but it may be something around a year. So when we get to a year out from the first vaccines given, we need to do it all over again with booster shots. Perhaps even more importantly, we are running up against vaccine hesitancy, which may ultimately prevent us from getting to herd immunity. That would be a tragedy.

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May 06 2021

Gerrymandering – Politics vs Logic

People are extremely social animals, and being social means that you need to learn the rules that govern social interaction and society. This applies to social animal species as well. Corvids, for example, can remember the faces of animals that harm or threaten them and will punish them later. They will also punish their own members for not following the rule – fail to warn us when a predator is coming and we won’t warn or protect you next time. Young children also are quickly socialized, and learn that there are rules of fairness. Fairness also means that you cannot change the rules on the fly in order to favor your own interests over others. Children will try, for example, to make up new rules to a game in the middle in order to accommodate what has already happened. Other children are likely to immediately see this as unfair and loudly protest.

We continue to engage in this behavior as adults. We’re just more adept at hiding it, or trying to justify it with some rationalization. One of the more blatant examples of this is gerrymandering. I have never heard anyone actually try to defend the practice. At best you get the lame excuse of – well, the other side will do it when they get a chance, so we have to do it to level the playing field. Or, more brazenly, they will just do it because they have the power to do so and think that this is justification enough.

Gerrymandering is the process of drawing congressional districts in order to favor your party. It has been accurately described as politicians choosing their voters, rather than voters choosing their politicians. It is one of the most obvious flaws in our current democratic system (referring to the US). It’s difficult to get rid of, however, because it can benefit both sides. The politicians in power benefit from gerrymandering, so it is self-sustaining. Gerrymandering is used in a couple of ways. One is to create safe seats, where one party has a lock and the other party has no chance. Safe seats favor extremism because candidates never have to appeal to the middle. Gerrymandering can also be used to favor a party by giving them more congressional seats than their share of the voters.

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May 04 2021

Living Materials

Sometimes technology is developed to serve a specific purpose or need. At other times technology is developed simply because it can be, and then people search for an application. Probably most of the time there is a combination – the technology is developed with a vague idea of how it can be used, but then has to find specific applications. This is partly what makes the future of technology difficult to predict. It is easier to predict if a technology is plausible and can be developed, and more difficult to predict if or how it will be used.

That is what I feel about living materials. A recent paper presents advances in, “Bioprinting of Regenerative Photosynthetic Living Materials.” The technology for 3D printing with biological materials is advancing nicely, with the most obvious application being medical, such as the printing of skin for grafting, and hopefully one day the printing of functional organs. This process looks at 3D printing of photosynthetic material into a fabric.

The process uses cellulose as a non-living structure. Cellulose is the material in plants that gives them their strength. It is a durable, flexible, and strong material that has the ability to retain its strength. Now before you get too excited, cotton is mostly cellulose. We are already making our clothing out of cellulose, and have been harvesting plant fibers for this purpose for thousands of years. The ability to 3D print cellulose directly into a fabric material is nice, and may have some specific uses. In this case the cellulose is designed to contain living microalgae. These algae can survive for several days without additional water or nutrients, and they can undergo photosynthesis. This period can be extended by providing water and nutrients. The material can also be “regenerated” in that they can be reused by adding new microalgae, or combined with new material.

OK, so now what?

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May 03 2021

The Science of Feel-Good Storytelling

From one perspective art is mostly a science that we understand better at an intuitive rather than analytical level. This does not reduce the creative elements off artistic expression, but it does mean there is an underlying empirical phenomenon to be understood. Storytelling, for example, has a basic structure, with elements that serve a specific purpose. One of the more famous attempts at breaking down the structure of certain types of stories is the Hero’s Journey by Joseph Campbell, in which he explains the common elements of epic quests in literature, that hold true even in more modern storytelling like Star Wars.

A recent study by German authors takes a similar look at the “feel good film”, which is not really a specific genre but more of a vague category. The “feel good film” is meant, as the name implies, to elevate the mood and be pleasant to watch. The authors point out that this is often a point of criticism by serious film critics, but simultaneously a point of praise from viewers. There is just as much of an art and science behind making a good feel-good film as any other type, so I think the criticism is unfair. I would focus more on the quality of any specific movie.

After extensive surveying, the authors found that the best formula for a feel good effect is the romantic comedy. The authors write;

“Often these involve outsiders in search of true love, who have to prove themselves and fight against adverse circumstances, and who eventually find their role in the community.”

Further, the authors found that the introduction of a “fairy tale” element served well to lighten the movie and enhance the feel-good effect. The movie that immediately came to mind when I read this was Enchanted, which seems to deliberately follow this formula (and it worked, extremely well). The authors also point out that such films require genuine drama and conflict. There appears to be a sweet spot – where we feel a real threat but we know the good guys are going to pull it out in the end. It’s like a rollercoaster – it’s simulated danger, but we know we are safe. In Enchanted the evil queen needs to seem genuinely menacing, for example.

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Apr 30 2021

Organic Electrochemical Synaptic Transistor

The title of this post should be provocative, if you think about it for a minute. For “organic” read flexible, soft, and biocompatible. An electrochemical synapse is essentially how mammalian brains work. So far we can be talking about a biological brain, but the last word, “transistor”, implies we are talking about a computer. This technology may represent the next step in artificial intelligence, developing a transistor that more closely resembles the functioning of the brain.

Let’s step back and talk about how brains and traditional computers work. A typical computer, such as the device you are likely using to read this post, has separate memory and logic. This means that there are components specifically for storing information, such as RAM (random-access memory), cache memory (fast memory that acts as a buffer between the processor and RAM) and for long-term storage hard drives and solid state drives. There are also separate components that perform logic functions to process information, such as the central CPU (central processing unit), graphics card, and other specialized processors.

The strength of computers is that they can perform some types of processing extremely fast, such as calculating with very large numbers. Memory is also very stable. You can store a billion word document and years later it will be unchanged. Try memorizing a billion words. The weakness of this architecture is that it is very energy intensive, largely because of the inefficiency of constantly having to transfer information from the memory components to the processing components. Processors are also very linear – they do one thing at a time. This is why more modern computers use multi-core processors, so they can have some limited multi-tasking.

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Apr 29 2021

Evolution of Multicellularity

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When studying the history of life evolutionary biologists and paleontologists have no choice but to look where the light is good. There are fossil windows into specific times and places in the past, and through these we glimpse a moment in biological history. We string these moments together to map out the past, but we know there are a lot of missing pieces.

One relatively dark passage in the history of life is the evolution of multicellularity. Beginning about 541 million years ago (mya) we can see the beginning of the Cambrian explosion – the appearance of a vast diversity of multicellular life. But this “explosion” was only partly due to rapid adaptive radiation, it is also an artifact of the evolution of hard parts that can fossilize. That development turned on the lights. The earliest known single-celled organisms are 3.77 billion years old, so we have a 3 billion year time span during which a lot must have happened. We know from changes in the atmosphere that cells evolved that could use sunlight to produce oxygen, and other critters evolved to eat them.

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Apr 27 2021

What Happens to Old Batteries?

Battery technology has been consistently improving for decades, making possible the shift to EV cars. Tesla’s North American Model S Long Range Plus now has an official range of 402 miles. At the low end EVs have ranges >250 miles. And every year they get a little better. At some point improving battery capacity will translate into smaller and cheaper batteries rather than just increased range. I wonder what that point will be. In other words, if you could have a car with a range anywhere from 500 miles to 5,000 miles, what would you pay for? Where is the optimal cost vs benefit?

Batteries are also increasingly a good idea for grid storage. Batteries have a lot of features that make them desirable for grid-level storage. They have good energy and power density, and can provide as-needed (dispatchable) energy almost instantly. You don’t need to ramp up a turbine – the energy is just there. They have great round-trip efficiency (rivaled only by pumped hydro), meaning little energy is lost in the storage and supply of energy.  They maintain their energy for a long enough time (they have slow self-discharge). They also have decent lifespans – charge-discharge cycles.

There are already battery grid storage facilities with 100-300 megawatt capacity, with more in the works, including a 409 megawatt system in South Florida. It is now cheaper for some utility companies to build a battery storage facility to add dispatchable capacity then to build a natural gas powered plant. There are other methods of grid storage, but batteries have had an increasing share of storage capacity over the last decade. But anytime one technology scales up by orders of magnitude, we may run into resource and infrastructure limitations. At some point we are going to stress our supplies of lithium, for example. As we radically change our energy infrastructure, therefore, we need to plan for a sustainable system. That means we need to think about what happens to batteries throughout their lifespan.

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