Dec 14 2021

Zoom Fatigue

I love the fact that three years ago no one would have any idea what the title of this post meant, and now pretty much everyone does. It’s a testament to the rapid pace of cultural change driven by digital technology. Over the last two years of the pandemic many people have become familiar with the app Zoom, which is a video conferencing app that was in the right place at the right time with the right features. There are, of course, other apps but Zoom clearly dominated the market.

Regardless of the app being used, video conferencing for many displaced school, lectures, work meetings, and even social gatherings. For those not already familiar with such technology it was a rapid education (Dude, you’re on mute!). Twenty-five percent of my patient visits are now over zoom, so I get to see the full spectrum of comfort with the technology, although overall it is definitely improving.

Many people, including Julie Boland who is a professor of psychology and linguistics, noticed that video conferencing can sometimes be more fatiguing than in person conversations. So she decided to research why that might be. Her initial hunch is that it might have something to do with the short delay in transmission times throwing off the natural rhythms of human conversation. Previous research had identified four contributors to Zoom fatigue – intense and slightly misaligned eye contact, being on camera, limited body movement, and lack of nonverbal communication.

As we learn to optimize the use of video conferences some of these factors are easily dealt with. For example, you can simply turn off your camera when you are not the speaker. This saves some digital throughput and energy as well, and means you don’t have to be on-camera the whole time, even when just listening. The misaligned eye-contact can be mitigated by placing the video window as close to your camera as possible, and adjusting the camera so that you are well-framed for others. Also, pure audio conversations can be just as good, and the video does not always add anything. I have been doing this for over 16 years, with five people recording a long podcast every week using just audio. You adapt.

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Dec 13 2021

Blaming the Victim

If someone gets seriously ill from COVID, to the point that they need to be hospitalized and even placed in ICU, and they were unvaccinated, how much should we blame them for their illness? This question can have practical implications, if we base decisions on allocating limited resources and insurance coverage of vaccine status. I wrote about this dilemma recently on Science-Based Medicine (and then discussed it on the SGU), and it sparked a lively discussion. Some of the responses amounted to justification for blaming the victim, which is essentially the core of the issue, and an important concept for activist skeptics to handle.

Blaming the victim can occur in many contexts. Within skeptical circles the most common manifestation is to blame people for being gullible (which is essentially the opposite of being skeptical). If someone, for example, falls for an obvious con it is easy to feel contempt or even anger toward that person for their gullibility. Sometimes gullibility is combined with scientific illiteracy. There are numerous pseudoscientific products on the market that require someone to have essentially no idea how the world works in order to believe the claims (or alternatively to compartmentalize any thoughts of mechanism of action). There are products that claim to improve the taste of wine simply by waving a plastic card over the glass, or to improve your athletic performance because you wear a small piece of rubber on your wrist – imbued with “frequencies” that harmonize with your body’s natural rhythms. There are fuel additives or devices that claim to dramatically improve the fuel efficiency of your car without any downside. And of course there are endless free energy devices that “they” don’t want you do know about.

It’s easy to write all this off as “caveat emptor” – if people pay a small price for their gullibility and scientific illiteracy, that is perhaps how it should be. We can then congratulate ourselves on being less gullible and more knowledgeable. Or we may moralize about individual responsibility, touting the fact that we invested the time to learn how to protect ourselves in a world full of con artists and scams. Blaming the victims of scams gives us the illusion of control (we can protect ourselves) and serves our sense of justice (people largely deserve what they get). But is this sort of blaming the victim morally or intellectually justified?

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Dec 09 2021

Predicting Solar Cell Efficiency

Solar cell or photovoltaic technology is now a critically important technology for our civilization. Solar power is now among the most cost-effective power sources we have, and the greenest in terms of carbon efficiency. It can also have a very small footprint depending on where we deploy it. Rooftop solar, for example, essentially has zero footprint in terms of land use. According to one calculation there is enough rooftop space in the world to provide more than the total energy consumption of the world. This approach is not practical, but it shows the potential.

Advances in solar technology are therefore incredibly valuable. The focus has primarily been on improved efficiency, which has about double in the last two decades from around 10% to around 20% for commercial solar panels. The theoretical limit of efficiency for single-layer silicon is 33.16% (the Shockley–Queisser limit). However, we can use multiple layers and other tricks to improve this theoretical limit to 68.7% and light concentration to boost this further to 86.8%. There is therefore a lot of head room above the current efficiency of about 20%. If we could, for example, double solar cell efficiency at the same production cost, that would cut the cost of installing solar in half, or double the potential capacity of rooftop solar. This would pair well with an electric vehicle with at-home charging.

Solar cell research could also reduce the cost of construction, make panels more resilient and flexible, and replace current rare or toxic elements with more common and environmentally friendly elements. There is a lot of room for improvement in this technology, and speeding up research to make those improvements is therefore highly valuable. Researchers at MIT and Google Brain may have just provided the world a tool for doing just that.

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Dec 07 2021

Democracy as a Complex Adaptive System

What do economics, biological evolution, and democracy have in common? They are all complex adaptive systems. This realization reflects one of the core strengths of a diverse intellectual background – there are meaningful commonalities underlying different systems and areas of knowledge. In fact, science and academia themselves are complex adaptive systems that benefit from diversity of knowledge and perspective. All such systems benefit from diversity, and suffer when that diversity is narrowed, possibly even fatally.

A recent collection of studies focuses on American democracy as a complex adaptive system, and explores the mathematical underpinnings of how democracies behave and change over time in response to specific variables. Some of the insights are not surprising, but the research adds mathematical rigor to these phenomena. For example, you will likely not be surprised to learn that social media echochambers (what they call “epistemic bubbles”) lead to increased polarization of political views. But how, exactly, does this happen?

What various researchers found is that when we obtain our political news from a network of like-minded people several things happen. First, the group tends to narrow over time in terms of political diversity. This happens because those who are considered “not pure enough” are ejected from the network, or leave because they feel less welcome. Further, people within the network tend to get access to less and less political news total, and the news they are exposed to is increasingly polarized. This doesn’t happen when such networks do not routinely share political news to begin with.

The core problem, therefore, seems to be the diversity of sources of information. Similar networks of people, in fact, can have a moderating effect on individual members, if the group maintains a diversity of sources of information reflecting a diversity of political opinions. Further, a healthy moderating effect is supported by individual members exploring outside the group for sources of information.

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Dec 03 2021

Using CRISPR For Sex Selection

Each year 6-7 billion male chicks are culled, because only females are needed for egg laying. Many other animals are also culled because one sex is desired either for food production or research. There are many research questions that are sex specific, and therefore large numbers of a single sex of a specific strain of mice may be required. Culling is a crude way to achieve these ends, and raises concerns about humanely treating animals.

For these reasons researchers have been looking for ways to achieve high degrees of sex selection in animals more efficiently and humanely. A new study published in Nature Communications seems to have made a significant advance in this direction, using CRISPR-Cas9 (a gene-editing system) to create a sex-selection system for either male or female mice that operates with 100% efficiency. The idea is clever – insert one half of a CRISPR-Cas9 kill switch into the X-chromosome of a female mouse, then insert the other half into either the X or Y chromosome of a male mouse. Only those embryos that get both halves of the CRISPR-Cas9 system (either XX or XY) will be killed at the early embryo stage.

This approach has been used before, in insects and zebrafish, but never in mammals. There are also other methods for sex selection that don’t rely on culling, such as sperm sorting, but this approach is not very efficient, and doesn’t work in birds where the females gametes determine sex. This new system has proven 100% effective in mice, and should easily port to other mammals such as pigs and cattle. The researches targeted a gene, the Top 1 gene, that codes for an enzyme critical for early DNA replication in a developing embryo. Inactivating this gene is a “suicide switch” for the embryo. This gene is also highly conserved, and the reason why it should work in all mammals, not just mice.

The researchers discovered that the early activity of this suicide switch has a specific advantage in sex-selection systems – it actually increases the yield (not just the ratio) of the desired sex compared to unselected litters. This happens because is many mammals with litters of multiple offspring, the females overproduce eggs, and not all eggs implant in the uterus. Therefore, if the eggs of the undesired sex are killed very early on more eggs from the desired sex can implant in the uterus and develop.

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Dec 02 2021

Is SpinLaunch Viable

Recently on the SGU we talked about a new company, SpinLaunch, which just conducted a test of their system to hurl satellites into orbit by spinning them up to high speeds then releasing them. We also did a follow up discussion on the show which will release this Saturday. It’s an interesting case study in how to assess the plausibility and viability of potential new technology.

The basic idea is a good one. Right now rockets are the way we get into space. The technology works, and reusable rockets have brought down the cost considerably. In the space shuttle era the cost of getting stuff into Earth orbit was about $100,000 per pound. Today SpaceX is below $2,000 per pound and hoping to get the cost under $1,000. Because the rockets themselves are now reusable, much of the cost is in fuel. Fuel use is governed by the rocket equation – it takes fuel to carry the fuel to carry the fuel you need to get the payload into orbit. The vast majority of the fuel, therefore, is used just to get the rest of the fuel up.

But perhaps there is another way. From the first conception of Earth orbit, the notion was that a very powerful canon would project something into orbit. This view held sway until the early 20th century when rocket technology became feasible. Even still, the idea persisted. In the 1960s the US and Canada developed the HARP (high altitude research project) system, which is essentially a giant gun that projected probes into the upper atmosphere for weather research. This system worked, and was canceled mainly for political reasons, not scientific ones.

For various reasons you cannot get something into orbit directly by shooting it from the surface of the Earth. In order to get into an orbit you will need rockets to get into the correct vector. But shooting a payload into the upper atmosphere at high velocity could essentially serve as the first stage, with rockets then taking over to get the payload into a stable orbit. This would dramatically reduce the fuel needed to get into orbit. The basic concept is to use an external source of power to accelerate the payload most of the way in order to avoid carrying all the power with the payload and therefore falling prey to the rocket equation.

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Nov 30 2021

Self-Replicating Xenobots

Placing “self-replicating” and any kind of “bots” in the same sentence immediately raises red flags, conjuring the image of reducing the surface of the world to gray goo. But that is not a concern here, for reasons that will become clear. There is a lot to unpack here, so let’s start with what xenobots are. They are biological machines, little “robots” assembled from living cells. In this case the source cells are embryonic pluripotent stem cells taken from the frog species Xenopus laevis. Researchers at the Allen Discovery Center at Tufts University have been experimenting with assembling these cells into functional biological machines, and have now added self-replication to their list of abilities.

Further, these xenobots replicate in a unique way, by what is known as kinematic self-replication. This is the first instance of this type of replication at the cell or organism level. The researchers point out that life has many ways of replicating itself: “fission, budding, fragmentation, spore formation, vegetative propagation, parthenogenesis, sexual reproduction, hermaphroditism, and viral propagation.” However, all these forms of self-replication have one thing in common – they happen through growth within or on the organism itself. By contrast, kinematic self-replication occurs entirely outside the organism itself, through the assemblage of external source material.

This process has been known at the molecular level, where molecules (like proteins) can guide the assemblage of identical molecules using external resources. However, this process is entirely unknown at the cellular level or above.

In the case of xenobots, the researchers placed them in an environment with lots of individual stem cells. The xenobots spontaneously gathered these stem cells into copies of themselves. However, these copies were not able to replicate themselves, so the process ended after one or a very limited number of generations. In a new study, the researchers set out to design an optimal xenobot that could sustain many generations of self-replication. They did not do this the old-fashioned way, through extensive trial and error. Rather, they used an AI simulation, which calculated for literally months, testing billions of possible configurations. It came up with a simple shape – a sphere with a mouth, looking incredibly like a Pac-Man. These xenobots are comprised of about 3,000 cells. The researchers assembled their xenobot Pac-Men and when placed in an environment with available stem cells they spontaneously herded them into spheres and then into copies of themselves. These copies were also able to make more copies of themselves, and so-on for many generations.

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Nov 29 2021

Get Ready for Omicron

Experts knew, and had been warning, that delta was not going to be the last Greek letter to sweep across the world. The World Health Organization (WHO) tracks variants of the SARS-CoV-2 virus which causes COVID-19. They track variants of interest (VOI) which have been identified as potentially problematic, and variants of concern (VOC) which have been demonstrated to have either increased infectivity, increased illness severity, and/or evasion of preventive measures (such as vaccines or masks). These variants are given a Greek letter designation as they are added to the list. What is now called the omicron variant has been added to the list of VOC. Here’s what we know so far.

The virus appears to have originated in South Africa. Fortunately, South Africa has a robust surveillance system and labs that can grow the virus and do a whole-genome sequence. They were therefore able to identify the variant quickly and share their information with the world. This isn’t the first variant to originate in South Africa, which raises the question of why this is the case? Increased surveillance may be part of the answer, but is not able to fully explain why. Some scientists speculate that South Africa’s large population of HIV infected and inadequately treated people provide a fertile breeding ground for new variants.

Variants are caused by mutations in the virus genome, some of which may alter proteins and therefore viral functions. SARS-CoV-2 does not have a particularly high mutation rate, but because we are having a world-wide pandemic there are lots of opportunities for new mutations to occur. It’s possible that when a person has a prolonged infection the viruses in their system are under selective pressure, so any mutation that might partly evade the immune system will be favored. Those with untreated HIV have an impaired immune response. This may be just enough to provide some selective pressure but not enough to fight off the infection, creating a breeding ground for new variants.

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Nov 23 2021

DART Asteroid Deflection Mission Ready for Launch

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Why is NASA planning on deliberately crashing a spacecraft into a small asteroid that poses no threat to the Earth? It’s a test of an asteroid deflection system – DART (Double Asteroid Redirection Test). Why the “double”? Most articles on the topic don’t say, and I had two hypotheses. The first is that the mission is targeting two asteroids, or actually a binary asteroid, Didymos (Greek for “twin”). Didymos has a primary asteroid that’s 780 meters across, and a smaller secondary asteroid 160 meters across that actually orbits the primary asteroid, and is therefore called a “moonlet”. However, the mission was originally supposed to be part of a pair of missions, with the second one by the ESA who were going to send their AIM probe to orbit and monitor Didymos during the DART mission. The ESA cancelled this mission, however, and now Didymos will be monitored by ground telescopes. But it turns out the “double” refers to the twin asteroids.

In any case, the purpose of the mission is to test out an asteroid defense system known as a kinetic impactor. The course of an asteroid can be altered by ramming something into it very fast. At first this seems like a crude method, but sometimes simple is best. The mission is part of NASA’s Planetary Defense Coordination Office. The European Space Agency (ESA) is also engaged in planetary defense, although their cancelling of AIM was disappointing. There are also international meetings on planetary defense, with calls for the USA, Russia and China to work together on this project. Russia, for their part, has proposed repurposing old ICBMs as asteroid busters. This would not be a kinetic impactor, but actually use nukes to blow up asteroids.

The DART mission is the first real test of an asteroid defense system. The spacecraft uses electric motors powered by solar panels, and will be going 6.6 km/s when it impacts the smaller Didymos asteroid. This impact will only divert the orbit of the asteroid by less than a percent, but that will be enough to change its orbit around the larger asteroid by several minutes, which can be observed from Earth. The craft is scheduled to launch tonight, November 23rd, at 10:21 pm PST aboard a SpaceX Falcon 9 rocket. It will intercept Didymos in late September 2022.

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Nov 22 2021

The Efficiency of Data Storage

As our world becomes increasingly digital, math becomes more and more important (not that it wasn’t always important). Even in ancient times, math was a critical technology improving our ability to predict the seasons, design buildings and roads, and have a functioning economy. In recent decades our world has been becoming increasingly virtual and digital, run by mathematical algorithms, simulations, and digital representations. We are increasingly building our world using methods that are driven by computers, and the clear trend in technology is toward a greater meshing of the virtual with the physical. One possible future destination of this trend is programmable matter, in which the physical world literally becomes a manifestation of a digital creation.

What this means is that the impact of even tiny incremental improvements in the efficiency of the underlying technology, computers, has increasingly powerful reverberations throughout our economy and our world. The nerds have truly inherited the Earth. This is why it is interesting science news that computer scientists at MIT have developed a tweak that may improve the efficiency with this computers store and retrieve data. William Kuszmaul and his team have demonstrated a way to improve what is known as linear probing hash tables. The underlying concept is interesting, at least for those curious about how the increasingly ubiquitous computer technology works.

Hash tables were developed in 1954 as a way for computers to store and locate data. When given a piece of data to store, the computer will calculate the “hash function of x, h(x)”. This will generate an essentially random number from 1 to 10,000. The computer then goes to that location in the sequential data array and stores the data there. If that location is already occupied by data then it probes forward until it finds an open slot and it puts the data there. When searching for the data to retrieve it does the same thing – goes to the assigned location and if the data is not there it probes forward until it finds it. If it encounters an open position first it concludes the data has been deleted.

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