Scientists have published the most extensive map of dark matter in the universe to date, based on a survey of 100 million galaxies. The findings don’t quite match with predictions made by computer models, suggesting that there is some physics at work which scientists do not yet understand. This, of course, is exciting for physicists.

As I discussed previously, we don’t know what dark matter is, but we are pretty confident it’s there. Dark matter does not give off any radiation, but it does have gravity, so we can see its gravitational effects. Based on these observations it seems that 80% of the matter in the universe is dark matter. This is a major area of research, because we do not know what dark matter is made of. It is probably some new particle we have not identified so far. This is where scientists live – on the edge of our current knowledge, peering into the unknown.

Part of that “peering” is gathering lots of data, and that is what the current study does. They used gravitational lensing to map the gravity of the universe, 80% of which is dark matter. Visible galaxies and dark matter cluster together, creating an overall structure to the universe. There are vast black voids with nothing, and there are tendrils of matter with galaxies, gas, and stars. The goal is to map this distribution, to see where all the stuff in the universe is.

They then compared this map to what we would predict based on our current understanding of the laws of physics. They started with a map of where all the matter was 350,000 years after the Big Bang, which was created by examining the cosmic background radiation. Then they model where that matter should have gone over the last 13.8 billion years based upon relativity and other physical laws. The map and the model were off by a few percent. The universe is more evenly distributed than the models predict. This may not sound like a lot, but physicists are used to dealing with high levels of precision. Physical laws tend to be very reliable. This is why we can make calculations and send a probe to Pluto 5 billion km away, and arrive precisely where they predicted. If the New Horizons probe was off course by a few percent, that would have been a disaster, both for the mission and our understanding of the relevant laws of physics.

This is why physicists love discrepancies between predicted and observed phenomena, even tiny ones. It means something is going on we are not aware of. This could be an effect we have not considered, an error in their experimental design or method of observation, or occasionally a tweak to our understanding of the laws of physics. The first two need to be thoroughly ruled out before new physics can be confidently postulated, and it is an increasingly rare event, but that is what physicists live for.

Continue Reading »

The pandemic has brought into sharp focus the potential danger of misinformation. There are times when we need to act collectively as a society to accomplish certain goals. This is particularly challenging in a society that is organized around a principle of individualism – a principle I endorse and value. Liberty is a precious right to be jealously defended. But it is not the only right, or principle of value. So at times we have to delicately balance various competing interests. I like my freedom, but I also really like not catching a deadly disease, or spreading it to my family.

In a perfect world (one we definitely do not live in) there would be no need for restrictive or draconian measures. All that would be necessary was distributing information – hey, if you want to protect yourself and others, wear a mask, socially distance, wash your hands, and get vaccinated. If you’re really interested, here are the facts, the published studies, the expert analysis, to back up these recommendations. Here are the error bars and level of uncertainty, the risk vs benefit analysis, and comparison to other options.

This approach is necessary, and works to a degree, but it is insufficient. There are two main shortcomings of the information approach. First, people are only semi-rational beings, not Vulcans. We are susceptible to tribalism, motivated reasoning, confirmation bias, and a host of cognitive biases, faulty heuristics, and logical fallacies. Our intuitions about balancing risk and benefit are also flawed, and we have a hard time dealing with very large numbers. Just peruse the comments to any blog post on this site that is even slightly controversial and you will find copious examples of every type of flawed thinking.

Continue Reading »

There have been many studies coming out recently looking at what it would take to mitigate climate change, and some patterns emerge from these analyses. First it is important to note that a certain amount of climate change has already happened, with 2020 being 1.2C warmer than the average year in the 19th century. More warming is also inevitable, even if we stopped all greenhouse gas emissions today.

The famous “12 years to stop global warming” notion refers to what it would take to stay below 1.5C warming, because below that level we can avoid major outcomes from climate change. That means getting close to net zero by 2030, which is absolutely not going to happen. Failing that the next goal is to stay below 2C warming. For that we likely need to get to net zero by 2050. That is possible, but will be extremely difficult.

One point of clarification that often gets misunderstood – no one is claiming that seriously bad outcomes will happen by 2030 or 2050, just that dangerous levels of warming will become inevitable by then if we don’t drastically reduce our CO2 release. The bad outcomes, like significant ocean level rise, kick in around 2100. This misunderstanding creates the illusion that scientists keep warning about climate change with endless deadlines that keep passing, while the world seems to be doing fine. Don’t be deceived by this. This is like ignoring your health, including warning signs like high cholesterol and high blood pressure, and claiming everything is fine, right up until the day you have a heart attack.

Continue Reading »

One of the unofficial functions of the skeptical movement is to serve as a form of institutional memory. Pseudoscience tends to come around in cycles. Each generation or two gets fascinated with the same topics only to eventually tire of them when they ultimately come to nothing. The die-hards stay on and keep the flame going until the next generation. Each time a paranormal or dubious topic rears up again, the same poor evidence, sloppy logic, common myths, gullible journalism, and old tropes are trotted out. This is where skeptics come in. We are like antibodies that remember the history and can respond to the nonsense much more quickly and effectively.

Fascination with UFOs (unidentified flying objects) has waxed and waned a few times over the last 60 years. After a relatively quiet period interest is once again peaking. While “UFO” simply refers to something in the sky we cannot identify, everyone knows we are really talking about alien spacecraft. Whether you want to be coy, technical, or explicit – that is always what people are really talking about. This time the government appears to be the cause of increased interest, which is a break from the standard narrative that the government knows all about it and is covering it up.

In 2007 Senator Harry Reid wanted to know if there was anything to the whole UFO thing. This lead to Pentagon investigations and eventually the formation of the Unidentified Aerial Phenomena Task Force (UAPTF). Next month they are due to give their official report to congress, and that is what has journalists all aflutter. They love stories like this – you can have serious-sounding people with connections to government talking about UFOs (now UAPs), and always there is the idea in the background that these can be aliens. The government officials won’t ever endorse – or deny – that idea. They take the coy route. We just want to know what’s going on. There is something interesting happening. Their answers seem like a wink and a nod. The journalists can tell a sensational story with plausible deniability, and never have to dig deep enough to tell the real story.

Continue Reading »

Imagine having an extra arm, or an extra thumb on one hand, or even a tail, and imagine that it felt like a natural part of your body and you could control it easily and dexterously. How plausible is this type of robotic augmentation? Could “Doc Oc” really exist?

I have been following the science of brain-machine interface (BMI) for years, and the research consistently shows that such augmentation is neurologically possible. There is still a lot of research to be done, and the ultimate limits of this technology will be discovered when real-world use becomes common. But the early signs are very good. Brain plasticity seems to be sufficient to allow for incorporation of robotic feedback and motor control into our existing neural networks. But there are still questions about how complete this incorporation can be, and what other neurological effects might result.

A new study further explores some of these questions. They studied 20 participants who them fitted with a “third thumb” opposite their natural thumb on one hand. Each thumb was customized and 3D printed, and could be controlled with pressure sensors under their toes. The subjects quickly learned how to control the thumb, and could soon do complex tasks, even while distracted or blindfolded. They further reports that over time the thumb felt increasingly like part of their body. They used the thumb, even at home, for 2-6 hours each day over five days. (Ten control subjects wore an inactive thumb.)

They used fMRI to scan the subjects at the beginning and end of their training. What they found was that subjects changed the way they used the muscles of their hand with the third thumb, in order to accommodate the extra digit. There were also two effects on the motor cortex representing the hand with the extra thumb. At baseline each finger moved independently would have a distinct pattern of motor cortex activation. After training, these patterns became less distinct. The researchers refer to this as a, “mild collapse of the augmented hand’s motor representation.” Second, there was a decrease in what is called “kinematic synergy.”

Continue Reading »

As project Artemis proceeds with plans not only to return to the Moon, but to produce the infrastructure for a long term presence, we need to deal with the issue of solar storms. If you haven’t seen the series, For All Mankind, I highly recommend it. In one episode they dramatize the effects of a particularly strong solar storm. I don’t think the special effects were accurate (the moon dust would not have kicked up like that) but the risk to human life was. If Artemis is going to be successful, we will need to be able to protect astronauts from these storms and the background radiation and be better able to predict them.

The solar wind is made mostly of plasma from the sun, protons and electrons, with a small percentage of helium and smaller still of heavier elements. The sun’s plasma is very hot and a the outer edges cannot be contained by the sun’s gravity. It will move along the magnetic field lines of the sun’s magnetic field and get pushed out streaming through the solar system like a bubble of radiation. We are protected from the constant flow of radiation by the Earth’s magnetic field. Once outside of low Earth orbit, however, that protection is gone. The Moon has no significant magnetic field and so astronauts would be constantly bathed in the solar wind. There are other sources of radiation as well, such as cosmic rays.

During the Apollo missions the astronauts each wore dosimeters to measure their total radiation exposure. Their total exposure was less than the maximum safe yearly exposure set for people, but this was over missions that lasted between 8-12 days. Radiation on the lunar surface is 200-1000 times that of the Earth’s surface, and 2.6 times that of the ISS.

Continue Reading »

The term “bullshitting” (in addition to its colloquial use) is a technical psychological term that means, “communication characterised by an intent to be convincing or impressive without concern for truth.” This is not the same as lying, in which one knows what they are saying is false. Bullshitters simply are indifferent to whether or not what they say is true. Their speech is optimized for sounding impressive, not accuracy. I have discussed before research showing that people who are more receptive to “pseudoprofound bullshit” are also more gullible in their evaluation of fake news and false claims.  Pseudoprofound bullshit are statements that superficially sound wise but are actually vacuous, and operationally for these studies are generated randomly, such as “Innocence gives rise to subjective chaos.”

A new study extends this bullshit research further by looking at the measured and perceived intelligence of subjects correlated to their ability to generate bullshit and receptivity towards it. The study is done to test an evolutionary hypothesis that intelligence evolved largely to provide social skill. Humans are an intensely social species, and the ability to navigate a complex social network requires cognitive skill. Therefore, the authors hypothesize, if this is true that the ability to bullshit (which is used as a marker for social skill) should correlate with intelligence. While the results of the study, which I will get to shortly, are interesting, I think we have to recognize that it is horrifically difficult to make such evolutionary statements of cause and effect.

Cognitive ability is so multifaceted that boiling down selective pressures to any one factor is essentially impossible. At best we can say that the ability to sound confident and convincing is a social skill that would provide one type of advantage to a social species. But we also have to recognize that individuals may pursue many different strategies favoring different attributes. Further, other personality characteristics could have a great influence on the willingness and ability to bullshit that have nothing to do with intelligence. And finally, intelligence bestows so many general advantages that could provide selective reinforcement that, again, it becomes problematic at best to isolate one factor as dominant. While I found the results of this study interesting, there is nothing here that is not incompatible with the interpretation that they are all epiphenomena, not primary selective pressures.

Continue Reading »

A recent audit of natural products manufacturers in Canada reveals how lacking regulations are in this industry. Scott Gavura does a good review of this over at SBM. I want to amplify some of what he says and add further context.

For background, so that everyone knows where I am coming from, I tend to take a nuanced approach to regulation. I believe in the power of capitalism and a free market to allocate resources in an organic way that will reflect, at least in part, actual merit. But free markets do not exist in a vacuum, they need to be crafted by an agreed upon set of rules. Further, there are always going to be people who try to work the system, bend the rules, and exploit others. Further, the evolutionary forces at work within a free market do not always favor acceptable outcomes. We know from history what happens in unregulated markets (we don’t have to guess) – they lead to fraud, exploitation, and monopoly. People will use wealth and power to rig the system so they gain more wealth and power at the expense of everyone else. The people who do this best will tend to succeed over time. While 1% of the population displays psychopathic traits, the figure is 4-12% among corporate CEOs.

Continue Reading »

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.

Continue Reading »

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.

Continue Reading »