Archive for the 'Skepticism' Category

Oct 31 2023

Ghosts Are Not Real

Published by under Skepticism

It’s Halloween, so there are a lot of fluff pieces about ghosts and similar phenomena circulating in the media. There are some good skeptical pieces as well, which is always nice to see. For this piece I did not want to frame the headline as a question, which I think is gratuitous, especially when my regular readers know what answer I am going to give. The best current scientific evidence has a solid answer to this question – ghosts are not a real scientific phenomenon.

For most scientists the story pretty much ends there. Spending any more serious time on the issue is a waste, even an academic embarrassment. But for a scientific skeptic there are several real and interesting questions. Why do so many people believe in ghosts? What naturalistic phenomena are being mistaken for ghostly phenomena? What specific errors in critical thinking lead to the misinterpretation of experiences as evidence for ghosts? Is what ghost-hunters are doing science, and if not, why not?

The first question is mostly sociological. A recent survey finds that 41% of Americans believe in ghosts, and 20% believe they have had an encounter with a ghost. We know that there are some personality traits associated with belief in ghosts. Of the big five, openness to experience and sensation is the biggest predictor. Also, intuitive thinking style rather than analytical is associated with a greater belief in the paranormal in general, including ghosts.

The relationship between religious belief and paranormal belief, including ghosts, is complicated. About half of studies show the two go together, while the rest show that being religous reduces the chance of believing in the paranormal. It likely depends on the religion, the paranormal belief, and how questions are asked. Some religious preach that certain paranormal beliefs are evil, therefore creating a stigma against them.

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Oct 16 2023

Gene Editing Chickens to Resist Bird Flu

Published by under Skepticism

There are 33 billion chickens in the world, mostly domestic species raised for egg-laying or meat. They are a high efficiency source of high quality protein. It’s the kind of thing we need to do if we want to feed 8 billion people. Similarly we have planted 4.62 billion acres of cropland. About 75% of the food we consume comes from 12 plant species, and 5 animal species. But there is an unavoidable problem with growing so much biological material – we are not the only things that want to eat them.

This is an – if you build it they will come – scenario. We are creating a food source for other organisms to eat and infect, which creates a lot of evolutionary pressure to do so. We are therefore locked in an evolutionary arms race against anything that would eat our lunch. And there is no easy way out of this. We have already has some epic failures, such as a fungus wiping out the global banana crop – yes, that already happened, a hundred years ago. And now it is happening again with the replacement banana. A virus almost wiped out the Hawaiian papaya industry, and citrus greening is threatening Florida’s citrus industry. The American chestnut essentially disappeared due to a fungus.

And now there is a threat to the world’s chickens. Last year millions were culled or died from the bird flu. As the avian flu virus evolves, it is quite possible that we will have a bird pandemic that could devastate a vital food source. Such viruses are also a potential source of zoonotic crossover to humans. Fighting this evolving threat requires that we use every tool we have. Best practices in terms of hygiene, maintaining biodiversity, and integrated pest management are all necessary. But they only mitigate the problem, not eliminate it. Vaccines are another option, and they will likely play an important role, but vaccines can be expensive and it’s difficult to administer 33 billion doses of chicken vaccines every year.

A recent study is a proof of concept for another approach – using modern gene editing tools to make chickens more resistant to infection. This approach saved the papaya industry, and brought back the American chestnut. It is also the best hope for crop bananas and citrus. Could it also stop the bird flu? H5N1 subtype clade 2.3.4.4b is an avian flu virus that is highly pathogenic, affects domestic and wild birds, and has cause numerous spillovers to mammals, including humans.

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Oct 12 2023

Evidence of Ancient Solar Flares

Published by under Skepticism

From time to time the Earth gets hit by a wave of energetic particles from the sun – solar flares or even coronal mass ejections (CMEs). In 1859 a large CME hit Earth (known as the Carrington Event), shorting out telegraphs, brightening the sky, and causing aurora deep into equatorial latitudes. If such an event were to occur today experts are not exactly sure what would happen, but it could take out satellites and short out parts of electrical grids. Interestingly, we have a historical record of how often such events have occurred in the past, mostly from tree rings.

A recent study extends this data with an analysis of subfossil pine trees from the Southern French Alps. These are trees partially preserved in bogs or similar environments, not yet fossilized but on their way. Trees are incredibly valuable as a store of historical information because of their rings – tree rings are a record of their annual growth, and the thickness of each ring reflects environmental conditions that year. Trees also live a long time – the Scots Pines used in the study live for 150-300 years. You can therefore create a record of annual tree rings continuously back in time (dendrochronologically dated tree-ring series) by matching up overlapping tree rings from different trees. We have such records going back about 13,000 years.

Tree ring also record another type of data – carbon 14-carbon 12 ratio. This is the basis of carbon 14 dating. The atmosphere has a certain ratio of carbon 14-12 which is reflected in living things that incorporate carbon into their structures. When the living thing dies, the clock starts ticking, with C14 decaying into C12, changing the ratio. One wrinkle for this method, however, is that the C14-12 ratio in the atmosphere is not fixed, it can fluxtuate from year to year. Essentially cosmic rays hit nitrogen (N14) atoms and convert them into carbon 14 in the upper atmosphere. This creates a steady of C14 in the atmosphere (and why it has not all decayed to C12 already).

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Oct 09 2023

Evidence and the Nanny State Part II

Published by under Skepticism

In Part I of this post I outlined some basic considerations in deciding how much the state should impose regulations on people and institutions in order to engineer positive outcomes. In the end the best approach, it seems to me, is a balanced one, where we consider the burden of regulations, both individually and cumulatively, compared to the benefit to individuals and society. We also need to consider unintended consequences and perverse incentives – people still need to feel as if they have individual responsibility, for example. It is a complex balancing act. In the end we should use objective evidence to determine what works and what doesn’t, or at least to be clear-eyed about the tradeoffs. In the US we have the benefit of fifty states which can experiment with various regulations, and this can potentially generate a lot of data.

Let’s take a look first at cigarette smoking regulations and health outcomes. At this point I don’t think I have to spend too much time establishing that smoking has negative health consequences. They have been well-documented in the last century and are not controversial, so we can take that as an established premise. Given that we know smoking is extremely unhealthy, which measures are justified by government in trying to limit smoking? Interestingly, the answer until around the 1980s was – very little. Surgeon General warnings was about it. Smoking in public was accepted (I caught the tail end of smoking in hospitals).

This was always curious to me. Here we have a product which is known to harm and even kill those who use the product as directed. And it’s addictive, which compromises the autonomy of users.  It is interesting to think what would happen if a company tried to introduce tobacco smoking as a product today. I doubt it would get past the FDA. But obviously smoking was culturally established before its harmful effects were generally known. I also always thought that the experience of prohibition created a general reluctance to go down that road again. But then data started coming out about the effects of second-hand smoke, and suddenly the calculus shifted. Now we were not just dealing with the interest of the state in protecting citizens from their own behavior, but the state protecting citizens from the choices of other citizens. This is entirely different – you may have a right to slowly kill yourself, but not to slowly kill me. The result was lots of data about smoking regulations.

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Jul 25 2023

Giant Eels, Loch Ness, and Probability

Published by under Skepticism

At this point it is pretty clear that the Loch Ness Monster (Nessie) does not exist. I know, logically it is impossible to prove a negative, so if we want to be technical we can say that the probability of a large creature similar to that believed to be Nessie approaches zero. The original 1934 photograph that created the Nessie phenomenon is a confessed hoax. We have 89 years of exploration, including countless visitors hoping to get a glimpse of the creature, camera in hand, and sonar surveys, submarine explorations, multiple webcams, and most recently a DNA survey. The DNA survey is perhaps the most conclusive, because it captures the DNA signature of everything living in the lake. There is no evidence of anything that can be a giant reptile.

If Nessie does not exist, then what have people been seeing all these years? I don’t think we need a concrete explanation for every single sighting. Hard evidence is one thing, but just eyewitness testimony is not really evidence. It is also well known that people misperceive things, confabulate, and are strongly influenced by expectations and desires. In short, if you look hard enough for the Loch Ness Monster, eventually you will see something and convince yourself that you saw the Loch Ness Monster. Even still, it is interesting to hypothesize about what phenomena might trigger alleged sightings, and not just of Nessie, but other lake monsters and cryptids.

One hypothesis is that some eye witnesses may have been seeing other aquatic creatures that might swim along the surface or breech. This includes large alligators, seals, groups of otters, and large fish such as sturgeon. The DNA evidence also ruled out these creatures for the Loch Ness (although they are still candidates for some other lake monsters). DNA, however, did raise the possibility that there are giant eels living in the Loch. Could an unusually giant eel have been mistaken for the neck or tail of Nessie?

A recent paper tests that hypothesis with some statistics. They used data for the European eel (Anguilla anguilla) to calculate likely size distributions. Eels grow throughout their lifespan, and can live over a hundred years. However, their growth is not linear, as it slows down as they age. They calculate that a sighting of a 1 meter long eel in Loch Ness has a probability of 1 in 50,000. Given the size of the lake and the fish stock, they conclude that such sightings are reasonable. So if you think a 1 meter eel could be mistaken for Nessie, it is a reasonable candidate, at least for some of the sightings over the years.

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Jul 18 2023

How We Determine What to Believe as True

Psychologists have been studying a very basic cognitive function that appears to be of increasing importance – how do we choose what to believe as true or false? We live in a world awash in information, and access to essentially the world’s store of knowledge is now a trivial matter for many people, especially in developed parts of the world. The most important cognitive skill in the 21st century may arguably be not factual knowledge but truth discrimination. I would argue this is a skill that needs to be explicitly taught in school, and is more important than teaching students facts.

Knowing facts is still important, because you cannot think in a vacuum. Our internal model of the world is build on bricks of fact, but before we take a brick and place it in our wall of knowledge, we have to decide if it is probably true or not. I have come to think about this in terms of three categories of skills – domain knowledge (with scientific claims this is scientific literacy), critical thinking, and media savvy.

Domain knowledge, or scientific literacy, is important because without a working knowledge of a topic you have no basis for assessing the plausibility of a new claim. Does it even make basic sense? An easily refutable claim may be accepted simply because you don’t know it is easily refutable. Critical thinking skills involve an understanding of the heuristics we naturally use to estimate truth, our cognitive biases, cognitive pitfalls like conspiracy thinking, how motivation affects our thought processes, and mechanisms of self deception. Media savvy involves understanding how to assess the reliability of information sources, how information ecosystems work, and how information is used by others to deceive us.

A recent study involves one aspect of this latter category – how do we assess the reliability of information sources and how this affects our bottom line assessment of whether or not something is true. The researchers did two studies involving 1,181 subjects. They gave the subjects factual information, then presented them with claims made by a media outlet. They were further told whether the media outlet intended to inform or deceive on this topic. They studies claims that are considered highly politicized and those that were not.

What they found is that subjects were more likely to deem a claim true if it came from a source considered to be trying to inform, and more likely to be false when the source was characterized as trying to deceive – even if the claims were the same. At first this result seems strange because the subjects were told the actual facts, so they knew absolutely (within the confines of the study) whether or not the claim was true.

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Jun 27 2023

Titan Disaster and Risk vs Benefit

Published by under Skepticism

There has been a lot of discussion regarding the recent disaster of the Titan submersible. Was the risk justified? Who should be responsible for the safety issues? Who should be on the hook for the millions of dollars the rescue effort took? And why did this tragedy garner more media coverage than 600 people dying off the coast of Greece when an overcrowded fishing crawler capsized?

To review, OceanGate is a submersible company that offers expeditions to the wreckage of the Titanic and other experiences. The company has been operating since 2008, making  more than 200 dives. The Titan was their latest vessel. It has made two previous successful trips to the Titanic, one in 2021, and one in 2022. The trip this month was it’s third trip. During descent to the wreckage, about 1 hour 45 minutes in, the control vessel suddenly lost contact with the Titan. It is believed that at that point the Titan suffered a “catastrophic implosion”. Essentially the pressure compartment failed. Even the tiniest crack would be enough, as any weak point would then collapse the entire chamber, kind of like popping a balloon but with high pressure on the outside rather than the inside. The only bright side of this being the fate of the Titan is that death would have been sudden, and the five passengers were not slowly suffocating for days trapped in the dark deep under water.

The disaster has sparked a lot of discussion about whether the entire enterprise is worth the risk. Some have called for a halt to any sight-seeing trips to the Titanic (anything other than research). At the other end of the spectrum was the OceanGate CEO Stockton Rush who now famously said:

“You know, at some point, safety is just pure waste. I mean, if you just want to be safe, don’t get out of bed, don’t get in your car, don’t do anything. At some point, you’re going to take some risk, and it really is a risk-reward question.”

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Jun 06 2023

How Much Carbon do Living Things Store?

Published by under Skepticism

Since we are in a “all hands on deck” situation when it comes to climate change, we need to take a look at all potential strategies for delaying and blunting global warming. The game at this point is all about peak warming – how much will the Earth warm before temperatures peak and then start to come down again (assuming we eventually drastically reduce our collective carbon footprint). This is not a win-lose, all-or-nothing scenario. It is very much a sliding scale – the higher peak warming is, the greater the chance of hitting some nasty tipping points and the greater the disruption to life and civilization.

Current evidence indicates that if we keep at 1.5 C warming or below (we are currently at 1 C warming) then we will probably be OK. If we exceed 2.5 C then there will very likely be disastrous results. Between 1.5 and 2.5 there is uncertainty. We don’t know precisely where the tipping points are (where will the Antarctic glaciers fail and essentially slide into the ocean), or exactly how bad things will get at each degree above 1.5. The problem is, we will almost certainly land somewhere between 1.5 and 2.5 C. So every bit we do to reduce that peak warming will likely have measurable benefits. For any intervention, therefore, the question is not whether or not it will prevent global warming, but rather how much will it likely reduce peak warming and lower the odds of the really bad stuff happening. This is why many experts believe we need an “all of the above” strategy. Every little bit helps.

With that in mind, what is the potential for reducing peak warming by maximizing living carbon sinks? Often this question is framed with respect to the most obvious living carbon sink – trees. Can we “prevent” global warming by planting a trillion trees, which should be framed as, how much does planting trees contribute to reducing peak warming. We can also frame it as, can we keep at or below a certain level (such as 1.5 C) if we plant enough trees?

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May 16 2023

The Role of Plausibility in Science

I have been writing blog posts and engaging in science communication long enough that I have a pretty good sense how much engagement I am going to get from a particular topic. Some topics are simply more divisive than others (although there is an unpredictable element from social media networks). I wish I could say that the more scientifically interesting topics garnered more attention and comments, but that is not the case. The overall pattern is that topics which have an ideological angle or affect people’s world-view inspire more passionate criticism or defense.  Timed drug release is an important topic, with implications for potentially anyone who has to take medication at some point in their lives. But it doesn’t challenge anyone’s world view. ESP, on the other hand, is a fringe topic likely to directly affect no one, but apparently is 70 times more interesting to my readers (using comments as a measure).

I also get e-mails, and my recent article on ESP research attracted a number of angry individuals who wanted to excoriate my closed minded “scientism”.  I think people care so much about ESP and other psi and paranormal phenomena because it gets at the heart of their beliefs about reality – do we live in a purely naturalistic and mechanistic world, or do we live in a world where the supernatural exists? Further, in my experience while many people are happy to praise the virtue of faith (believing without knowing) in reality they desperately want there to be objective evidence for their beliefs. Meanwhile, I think it’s fair to say that a dedicated naturalist would find it “disturbing” (if I can paraphrase Darth Vader) if there really were convincing evidence that contradicts naturalism. Both sides have an out, as it were. Believers in a supernatural universe can always say that the supernatural by definition is not provable by science. One can only have faith. This is a rationalization that has the virtue of being true, if properly formulated and utilized. Naturalists can also say that if you have actual scientific evidence of an alleged paranormal phenomenon, then by definition it’s not paranormal. It just reflects a deeper reality and points in the direction of new science. Yeah!

Regardless of what you believe deep down about the ultimate nature of reality (and honestly, I couldn’t care less, as long as you don’t think you have the right to impose that view on others), the science is the science. Science follows methodological naturalism, and is agnostic toward the supernatural question. It operates within a framework of naturalism, but recognizes this is a construct, and does not require philosophical naturalism. So you can have your faith, just don’t mess with science.

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May 15 2023

Student Attitudes Toward AI in the Class

Published by under Education,Skepticism

Researchers recently published an extensive survey of almost 6,000 students across academic institution in Sweden. The results are not surprising, but they do give a snapshot of where we are with the recent introduction of large language model AIs.

Most students, 56%, reported that they use Chat GPT in their studies, and 35% regularly. More than half do not know if their school has guidelines on AI use in their classwork, and 62% believe that using a chatbot during an exam is cheating (so 38% do not think that). What this means is that most students are using AI for their classwork, but they don’t know what the rules are and are unclear on what would constitute cheating.  Also, almost half of students think that using AI makes them more efficient learners, and many commented that they feel it has improved their own language and thinking skills.

So – is the use of AI in education a bane or a boon? Of course, asking students is only one window into this question. Educators have concerns about AI creating a lazy student, that can serve up good-enough answers to get by. There are also concerns about outright cheating, although that has to be carefully defined. Some teachers don’t know how to react when students turn in essays that appear to have been written by a chat bot. But many also think there is tremendous potential is using AI as an educational tool.

Clearly the availability of the latest generation of large language model AIs is a disruptive technology. Schools are now scrambling to deal with it, but I think they have no choice. Students are moving fast, and if schools don’t keep up they will miss an opportunity and fail to mitigate the potential downsides. What is clear is that AI has the potential to significantly change education. Simplistic solutions like just banning the use of AI is not going to work.

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