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Set in an English manor in 1890, Botany Manor is a video game that places you in the shoes of a botanist working on a herbarium of forgotten flora

Part 3: Dr. John Ioannidis said his biggest mistake was the he "underestimated how much power politics and media and powers outside of science, could have on science." Really? 

The post Dr. John Ioannidis: “The Biggest Mistakes I am Sure Are Mine.” first appeared on Science-Based Medicine.

On October 17, 2005 the talk show host and comedian Stephen Colbert introduced the word “truthiness” in the premier episode of his show The Colbert Report:1 “We’re not talking about truth, we’re talking about something that seems like truth— the truth we want to exist.”2 Since then the word has become entrenched in our everyday vocabulary but we’ve largely lost Colbert’s satirical critique of “living in a post-truth world.” Truthiness has become our truth. Kellyanne Conway opened the door to “alternative facts”3 while Oprah Winfrey exhorted you to “speak your truth.”4 And the co-founder of Skeptic magazine, Michael Shermer, has begun to regularly talk to his podcast guests about objective external truths and subjective internal truths, inside of which are historical truths, political truths, religious truths, literary truths, mythical truths, scientific truths, empirical truths, narrative truths, and cultural truths.5 It is an often-heard complaint to say that we live in a post-truth world, but what we really have is far too many claims for it. Instead, we propose that the vital search for truth is actually best continued when we drop our assertions that we have something like an absolute Truth with a capital T.

Why is that? Consider one of our friends who is a Young Earth creationist. He believes the Bible is inerrant. He is convinced that every word it contains, including the six days of creation story of the universe, is Truth (spelled with a capital T because it is unquestionably, eternally true). From this position, he has rejected evidence brought to him from multiple disciplines that all converge on a much older Earth and universe. He has rejected evidence from fields such as biology, paleontology, astronomy, glaciology, and archeology, all of which should reduce his confidence in the claim that the formation of the Earth and every living thing on it, together with the creation of the sun, moon, and stars, all took place in literally six Earth days. Even when it was pointed out to him that the first chapter of Genesis mentions liquid water, light, and every kind of vegetation before there was a sun or any kind of star whatsoever, he claimed not to see a problem. His reply to such doubts is to simply say, “with God, all things are possible.”6

Lacking any uncertainty about the claim that “the Bible is Truth,” this creationist has only been able to conclude two things when faced with tough questions: (1) we are interpreting the Bible incorrectly, or (2) the evidence that appears to undermine a six-day creation is being interpreted incorrectly. These are inappropriately skeptical responses, but they are the only options left to someone who has decided beforehand that their belief is Truth. And, importantly, we have to admit that this observation could be turned back on us too. As soon as we become absolutely certain about a belief—as soon as we start calling something a capital “T” Truth—then we too become resistant to any evidence that could be interpreted as challenging it. After all, we are not absolutely certain that the account in Genesis is false. Instead, we simply consider it very, very unlikely, given all of the evidence at hand. We must keep in mind that we sample a tiny sliver of reality, with limited senses that only have access to a few of possibly many dimensions, in but one of quite likely multiple universes. Given this situation, intellectual humility is required.

Some history and definitions from philosophy are useful to examine all of this more precisely. Of particular relevance is the field of epistemology, which studies what knowledge is or can be. A common starting point is Plato’s definition of knowledge as justified true belief (JTB).7 According to this JTB formulation, all three of those components are necessary for our notions or ideas to rise to the level of being accepted as genuine knowledge as opposed to being dismissible as mere opinion. And in an effort to make this distinction clear, definitions for all three of these components have been developed over the ensuing millennia. For epistemologists, beliefs are “what we take to be the case or regard as true.”8 For a belief to be true, it doesn’t just need to seem correct now; “most philosophers add the further constraint that a proposition never changes its truth-value in space or time.”9 And we can’t just stumble on these truths; our beliefs require some reason or evidence to justify them.10

Readers of Skeptic will likely be familiar with skeptical arguments from Agrippa (the problem of infinite regress11), David Hume (the problem of induction12), Rene Descartes (the problem of the evil demon13), and others that have chipped away at the possibility of ever attaining absolute knowledge. In 1963, however, Edmund Gettier fully upended the JTB theory of knowledge by demonstrating—in what has come to be called “Gettier problems”14—that even if we managed to actually have a justified true belief, we may have just gotten there by a stroke of good luck. And the last 60 years of epistemology have shown that we can seemingly never be certain that we are in receipt of such good fortune.

This philosophical work has been an effort to identify an essential and unchanging feature of the universe—a perfectly justified truth that we can absolutely believe in and know. This Holy Grail of philosophy surely would be nice to have, but it makes sense that we don’t. Ever since Darwin demonstrated that all of life could be traced back to the simplest of origins, it has slowly become obvious that all knowledge is evolving and changing as well. We don’t know what the future will reveal and even our most unquestioned assumptions could be upended if, say, we’ve actually been living in a simulation all this time, or Descartes’ evil demon really has been viciously deluding us. It only makes sense that Daniel Dennett titled one of his recent papers, “Darwin and the Overdue Demise of Essentialism.”15

So, what is to be done after this demise of our cherished notions of truth, belief, and knowledge? Hold onto them and claim them anyway, as does the creationist? No. That path leads to error and intractable conflict. Instead, we should keep our minds open, and adjust and adapt to evidence as it becomes available. This style of thinking has become formalized and is known as Bayesian reasoning. Central to Bayesian reasoning is a conditional probability formula that helps us revise our beliefs to be better aligned with the available evidence. The formula is known as Bayes’ theorem. It is used to work out how likely something is, taking into account both what we already know as well as any new evidence. As a demonstration, consider a disease diagnosis, derived from a paper titled, “How to Train Novices in Bayesian Reasoning:”

10 percent of adults who participate in a study have a particular medical condition. 60 percent of participants with this condition will test positive for the condition. 20 percent of participants without the condition will also test positive. Calculate the probability of having the medical condition given a positive test result.16

Most people, including medical students, get the answer to this type of question wrong. Some would say the accuracy of the test is 60 percent. However, the answer must be understood in the broader context of false positives and the relative rarity of the disease.

Simply putting actual numbers on the face of these percentages will help you visualize this. For example, since the rate of the disease is only 10 percent, that would mean 10 in 100 people have the condition, and the test would correctly identify six of these people. But since 90 of the 100 people don’t have the condition, yet 20 percent of them would also receive a positive test result, that would mean 18 people would be incorrectly flagged. Therefore, 24 total people would get positive test results, but only six of those would actually have the disease. And that means the answer to the question is only 25 percent. (And, by the way, a negative result would only give you about 95 percent likelihood that you were in the clear. Four of the 76 negatives would actually have the disease.)

Now, most usages of Bayesian reasoning won’t come with such detailed and precise statistics. We will very rarely be able to calculate the probability that an assertion is correct by using known weights of positive evidence, negative evidence, false positives, and false negatives. However, now that we are aware of these factors, we can try to weigh them roughly in our minds, starting with the two core norms of Bayesian epistemology: thinking about beliefs in terms of probability and updating one’s beliefs as conditions change.17 We propose it may be easier to think in this Bayesian way using a modified version of a concept put forward by the philosopher Andy Norman, called Reason’s Fulcrum.18

Figure 1. A Simple Lever. Balancing a simple lever can be achieved by moving the fulcrum so that the ratio of the beam is the inverse of the ratio of mass. Here, an adult who is three times heavier than the child is balanced by giving the child three times the length of beam. The mass of the beam is ignored. Illustrations in this article by Jim W.W. Smith

Like Bayes, Norman asserts that our beliefs ought to change in response to reason and evidence, or as David Hume said, “a wise man proportions his belief to the evidence.”19 These changes could be seen as the movement of the fulcrum lying under a simple lever. Picture a beam or a plank (the lever) with a balancing point (the fulcrum) somewhere in the middle, such as a playground teeter-totter. As in Figure 1, you can balance a large adult with a small child just by positioning the fulcrum closer to the adult. And if you know their weight, then the location of that fulcrum can be calculated ahead of time because the ratio of the beam length on either side of the fulcrum is the inverse of the ratio of mass between the adult and child (e.g., a three times heavier person is balanced by a distance having a ratio of 1:3 units of distance).

If we now move to the realm of reason, we can imagine substituting the ratio of mass between an adult and child by the ratio of how likely the evidence is to be observed between a claim and its counterclaim. Note how the term in italics captures not just the absolute quantity of evidence but the relative quality of that evidence as well. Once this is considered, then the balancing point at the fulcrum gives us our level of credence in each of our two competing claims.

Figure 2. Ratio of 90–10 for People Without–With the Condition. A 10 percent chance of having a condition gives a beam ratio of 1:9. The location of the fulcrum shows the credence that a random person should have about their medical status.

To see how this works for the example previously given about a test for a medical condition, we start by looking at the balance point in the general population (Figure 2). Not having the disease is represented by 90 people on the left side of the lever, and having the disease is represented by 10 people on the right side. This is a ratio of 9:1. So, to get our lever to balance, we must move the fulcrum so that the length of the beam on either side of the balancing point has the inverse ratio of 1:9. This, then, is the physical depiction of a 10 percent likelihood of having the medical condition in the general population. There are 10 units of distance between the two populations and the fulcrum is on the far left, 1 unit away from all the negatives.

Figure 3. Ratio of 18 False Positives to 6 True Positives. A 1 to 3 beam ratio illustrates a 25 percent chance of truly having this condition. The location of the fulcrum shows the proper level of credence for someone if they receive a positive test.

Next, we want to see the balance point after a positive result (Figure 3). On the left: the test has a 20 percent false positive rate, so 18 of the 90 people stay on our giant seesaw even though they don’t actually have the condition. On the right: 60 percent of the 10 people who have the condition would test positive, so this leaves six people. Therefore, the new ratio after the test is 18:6, or 3:1. This means that in order to restore balance, the fulcrum must be shifted to the inverse ratio of 1:3. There are now four total units of distance between the left and right, and the fulcrum is 1 unit from the left. So, after receiving a positive test result, the probability of having the condition (being in the group on the right) is one in four or 25 percent (the portion of beam on the left). This confirms the answer we derived earlier using abstract mathematical formulas, but many may find the concepts easier to grasp based on the visual representation.

To recap, the position of the fulcrum under the beam is the balancing point of the likelihood of observing the available evidence for two competing claims. This position is called our credence. As we become aware of new evidence, our credence must move to restore a balanced position. In the example above, the average person in the population would have been right to hold a credence of 10 percent that they had a particular condition. And after getting a positive test, this new evidence would shift their credence, but only to a likelihood of 25 percent. That’s worse for the person, but actually still pretty unlikely. Of course, more relevant evidence in the future may shift the fulcrum further in one direction or another. That is the way Bayesian reasoning attempts to wisely proportion one’s credence to the evidence.

Figure 4. Breaking Reason’s Fulcrum. Absolute certainty makes Bayes’ theorem unresponsive to evidence in the same way that a simple lever is unresponsive to mass when it becomes a ramp.

What about our Young Earth creationist friend? When using Bayes’ theorem, the absolute certainty he holds starts with a credence of zero percent or 100 percent and always results in an end credence of zero percent or 100 percent, regardless of what any possible evidence might show. To guard against this, the statistician Dennis Lindley proposed “Cromwell’s Rule,” based on Oliver Cromwell’s famous 1650 quip: “I beseech you, in the bowels of Christ, think it possible that you may be mistaken.”20 This rule simply states that you should never assign a probability of zero percent or 100 percent to any proposition. Once we frame our friend’s certainty in the Truth of biblical inerrancy as setting his fulcrum to the extreme end of the beam, we get a clear model for why he is so resistant to counterevidence. Absolute certainty breaks Reason’s Fulcrum. It removes any chance for leverage to change a mind. When beliefs reach the status of “certain truth” they simply build ramps on which any future evidence effortlessly slides off (Figure 4).

So far, this is the standard way of treating evidence in Bayesian epistemology to arrive at a credence. The lever and fulcrum depictions provide a tangible way of seeing this, which may be helpful to some readers. However, we also propose that this physical model might help with a common criticism of Bayesian epistemology. In the relevant academic literature, Bayesians are said to “hardly mention” sources of knowledge, the justification for one’s credence is “seldom discussed,” and “Bayesians have hardly opened their ‘black box’, E, of evidence.”21 We propose to address this by first noting it should be obvious from the explanations above that not all evidence deserves to be placed directly onto the lever. In the medical diagnosis example, we were told exactly how many false negatives and false positives we could expect, but this is rarely known. Yet, if ten drunken campers over the course of a few decades swear they saw something that looked like Bigfoot, we would treat that body of evidence differently than if it were nine drunken campers and footage from one high-definition camera of documentarians working for the BBC. How should we depict this difference between the quality of evidence versus the quantity of evidence?

We don’t yet have firm rules or “Bayesian coefficients” for how to precisely treat all types of evidence, but we can take some guidance from the history of the development of the scientific method. Evidential claims can start with something very small, such as one observation under suspect conditions given by an unreliable observer. In some cases, perhaps that’s the best we’ve got for informing our credences. Such evidence might feel fragile, but…who knows? The content could turn out to be robust. How do we strengthen it? Slowly, step by step, we progress to observations with better tools and conditions by more reliable observers. Eventually, we’re off and running with the growing list of reasons why we trust science: replication, verification, inductive hypotheses, deductive predictions, falsifiability, experimentation, theory development, peer review, social paradigms, incorporating a diversity of opinions, and broad consensus.22

We can also bracket these various knowledgegenerating activities into three separate categories for theories. The simplest type of theory we have explains previous evidence. This is called retrodiction. All good theories can explain the past, but we have to be aware that this is also what “just-so stories” do, as in Rudyard Kipling’s entertaining theory for how Indian rhinoceroses got their skin—cake crumbs made them so itchy they rubbed their skin until it became raw, stretched, and all folded up.23

Even better than simply explaining what we already know, good theories should make predictions. Newton’s theories predicted that a comet would appear around Christmastime in 1758. When this unusual sight appeared in the sky on Christmas day, the comet (named for Newton’s close friend Edmund Halley) was taken as very strong evidence for Newtonian physics. Theories such as this can become stronger the more they explain and predict further evidence.

This article appeared in Skeptic magazine 28.4
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Finally, beyond predictive theories, there are ones that can bring forth what William Whewell called consilience.24 Whewell coined the term scientist and he described consilience as what occurs when a theory that is designed to account for one type of phenomenon turns out to also account for another completely different type. The clearest example is Darwin’s theory of evolution. It accounts for biodiversity, fossil evidence, geographical population distribution, and a huge range of other mysteries that previous theories could not make sense of. And this consilience is no accident—Darwin was a student of Whewell’s and he was nervous about sharing his theory until he had made it as robust as possible.

Figure 5. The Bayesian Balance. Evidence is sorted by sieves of theories that provide retrodiction, prediction, and consilience. Better and better theories have lower rates of false positives and require a greater movement of the fulcrum to represent our increased credence. Evidence that does not yet conform to any theories at all merely contributes to an overall skepticism about the knowledge we thought we had.

Combining all of these ideas, we propose a new way (Figure 5) of sifting through the mountains of evidence the world is constantly bombarding us with. We think it is useful to consider the three different categories of theories, each dealing with different strengths of evidence, as a set of sieves by which we can first filter the data to be weighed in our minds. In this view, some types of evidence might be rather low quality, acting like a medical test with false positives near 50 percent. Such poor evidence goes equally on each side of the beam and never really moves the fulcrum. However, other evidence is much more likely to be reliable and can be counted on one side of the beam at a much higher rate than the other (although never with 100 percent certainty). And evidence that does not fit with any theory whatsoever really just ought to make us feel more skeptical about what we think we know until and unless we figure out a way to incorporate it into a new theory.

We submit that this mental model of a Bayesian Balance allows us to adjust our credences more easily and intuitively. Also, it never tips the lever all the way over into unreasonable certainty. To use it, you don’t have to delve into the history of philosophy, epistemology, skepticism, knowledge, justified true beliefs, Bayesian inferences, or difficult calculations using probability notation and unknown coefficients. You simply need to keep weighing the evidence and paying attention to which kinds of evidence are more or less likely to count. Remember that observations can sometimes be misleading, so a good guiding principle is, “Could my evidence be observed even if I’m wrong?” Doing so fosters a properly skeptical mindset. It frees us from the truth trap, yet enables us to move forward, wisely proportioning our credences as best as the evidence allows us.

About the Author

Zafir Ivanov is a writer and public speaker focusing on why we believe and why it’s best we believe as little as possible. His lifelong interests include how we form beliefs and why people seem immune to counterevidence. He collaborated with the Cognitive Immunology Research Initiative and The Evolutionary Philosophy Circle. Watch his TED talk.

Ed Gibney writes fiction and philosophy while trying to bring an evolutionary perspective to both of those pursuits. He has previously worked in the federal government trying to make it more effective and efficient. He started a Special Advisor program at the U.S. Secret Service to assist their director with this goal, and he worked in similar programs at the FBI and DHS after business school and a stint in the Peace Corps. His work can be found at evphil.com.

References

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7. https://rb.gy/5sdni
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10. https://rb.gy/1no1h
11. https://rb.gy/eh2fl
12. https://rb.gy/2k9xa
13. Gillespie, M. A. (1995). Nihilism Before Nietzsche. University of Chicago Press.
14. https://rb.gy/4iavf
15. https://rb.gy/crv9j
16. https://rb.gy/zb862
17. https://rb.gy/dm5qc
18. Norman, A. (2021). Mental Immunity: Infectious Ideas, Mind-Parasites, and the Search for a Better Way to Think. Harper Wave.
19. https://rb.gy/2k9xa
20. Jackman, S. (2009). The Foundations of Bayesian Inference. In Bayesian Analysis for the Social Sciences. John Wiley & Sons.
21. Hajek, A., & Lin, H. (2017). A Tale of Two Epistemologies? Res Philosophica, 94(2), 207–232.
22. Oreskes, N. (2019). Why Trust Science? Princeton University Press.
23. https://rb.gy/2us27
24. Whewell, W. (1847). The Philosophy of the Inductive Sciences, Founded Upon Their History. London J.W. Parker.

Last year’s marine heatwaves saw an unprecedented decline in the growth of phytoplankton and algae, which many animals in the oceans depend on for food

A new study reveals how noise is generated and propagated from these engines, technically known as boundary layer ingesting (BLI) ducted fans.

Both a special diet that excludes “FODMAP” compounds and a low-carb high-fibre diet were effective

A new robotic suction cup which can grasp rough, curved and heavy stone, has been developed by scientists.

A new robotic suction cup which can grasp rough, curved and heavy stone, has been developed by scientists.

A new typing model simulates the typing process instead of just predicting words.

A new typing model simulates the typing process instead of just predicting words.

The first health impact study of coal train pollution centers on the San Francisco Bay Area, with scientists finding communities near passing coal trains suffer worse health outcomes.

Contrary to previous assumptions, nerve cells in the human neocortex are wired differently than in mice. The study found that human neurons communicate in one direction, while in mice, signals tend to flow in loops. This increases the efficiency and capacity of the human brain to process information. These discoveries could further the development of artificial neural networks.

The energy density of supercapacitors -- battery-like devices that can charge in seconds or a few minutes -- can be improved by increasing the 'messiness' of their internal structure. Researchers used experimental and computer modelling techniques to study the porous carbon electrodes used in supercapacitors. They found that electrodes with a more disordered chemical structure stored far more energy than electrodes with a highly ordered structure.

Scientists have discovered that the magnetic nanobubbles known as skyrmions can be moved by electrical currents, attaining record speeds up to 900 m/s. Anticipated as future bits in computer memory, these nanobubbles offer enhanced avenues for information processing in electronic devices. Their tiny size provides great computing and information storage capacity, as well as low energy consumption. Until now, these nanobubbles moved no faster than 100 m/s, which is too slow for computing applications. However, thanks to the use of an antiferromagnetic material as medium, the scientists successfully had the skyrmions move 10 times faster than previously observed. These results offer new prospects for developing higher-performance and less energy-intensive computing devices.

Scientists have developed artificial heterostructures made of freestanding 2D and 3D membranes that have an energy density up to 19 times higher than commercially available capacitors.

Back in the 1960s and 1970s, Apollo astronauts set up a collection of lunar seismometers to detect possible Moon quakes. These instruments monitored lunar activity for eight years and gave planetary scientists an indirect glimpse into the Moon’s interior. Now, researchers are developing new methods for lunar quake detection techniques and technologies. If all goes well, the Artemis astronauts will deploy them when they return to the Moon.

Fiber optic cable is the heart of a seismology network to be deployed on the Moon by future Artemis astronauts.

The new approach, called distributed acoustic sensing (DAS), is the brainchild of CalTech geophysics professor Zhongwen Zhan. It sends laser beams through a fiber optic cable buried just below the surface. Instruments at either end measure how the laser light changes during the shake-induced tremors. Basically Zhan’s plan turns the cable into a sequence of hundreds of individual seismometers. That gives precise information about the strength and timing of the tremors. Amazingly, a 100-kilometer fiber optic cable would function as the equivalent of 10,000 seismometers. This cuts down on the number of individual seismic instruments astronauts would have to deploy. It probably also affords some cost savings as well.

A seismometer station deployed on the Moon during the Apollo 15 mission. Courtesy NASA. DAS and Apollo on the Moon

Compare DAS the Apollo mission seismometer data and it becomes obvious very quickly that DAS is a vast improvement. In the Apollo days, the small collection of instruments left behind on the Moon provided information that was “noisy”. Essentially, when the seismic waves traveled through different parts of the lunar structure, they got scattered. This was particularly true when they encountered the dusty surface layer. The “noise” basically muddied up the signals.

The layout for the Apollo Lunar Seismic Profiling Experiment for the Apollo 17 mission. Courtesy Nunn, et al. What DAS Does to Detect Quakes on the Moon

The DAS system stations laser emitters and data collectors at each end of a fiber optic cable. This allows for multiple widely spaced installations that measure light as it transits the network. The cable consists of glass strands, and each strand contains tiny imperfections. That sounds bad, but each imperfection provides a useful “waypoint” that reflects a little bit of the light back to the source. That information gets recorded as part of a larger data set. Setting up such a system of telecommunications cables over a large area provides millions of waypoints that scientists can use to measure seismic movements on Earth.

A recent study led by CalTech postdoctoral researcher Qiushi Zhai deployed this type of DAS-enabled fiber optic cable system in Antarctica. The conditions mimic some of the environmental challenges of a lunar deployment—it’s freezing cold, very dry, and far removed from human activities. The sensors measured the small movements of caused by ice cracking and moving around. Those types of signals are perfect analogs to lunar quakes.

Aerial view of Antarctica. A prototype of the lunar DAS system for the Artemis missions to the Moon detected tiny tremors from ice movements here. Photo credit: L. McFadden 2008 Measuring a Lunar Quake Using DAS

Since DAS works well measuring tiny tremors induced by ice, it seems like the perfect “next step” in doing lunar seismology. On the Moon, the fiber optic cable would be buried (just as cables are on Earth) a few centimeters below the level of the regolith. It will sit there waiting for the next quake, which probably won’t take long, since the Moon seems to quiver frequently. When one strikes, its seismic waves will move through the ground from the source. They’ll wiggle the cable. That will affect the light-travel path inside. The actions of light hitting thousands of imperfections inside the cable will provide lunar geologists with high-precision data about moonquakes. That includes their origins, travel time, and other aspects of the wave that will help them understand more about the lunar structure they travel through.

The distributed nature of the seismic network will have a big advantage over the Apollo-style individual seismometers used in the past. And, there are other reasons to use DAS, according to Zhai. “Another advantage of using DAS on the Moon is that a fiber optic cable is physically quite resilient to the harsh lunar environment: high radiation, extreme temperatures, and heavy dust,” Zhai said.

Moon Structure and DAS

Zhai is the first author of a paper describing the DAS system, which should allow scientists to detect close to 100 percent of Moon tremors. The paper offers insight into the advantages that DAS offers. In particular, such an array stretched across large areas of the Moon should provide much higher-quality data about even the smallest tremors that shake the surface.

Since the Moon is not tectonically active, its quakes don’t occur from the same causes as they do on Earth. Some happen during the sunset/sunrise period when temperature changes affect the surface. Others happen thanks to Earth’s pull on the Moon, and still others occur because the Moon is still cooling and contracting. Zhai’s paper suggests that DAS could detect about 15 moonquakes per day, and perhaps help better characterize the thermal moonquakes that happen at sunrise/sunset and the deeper ones that occur during perigee and apogee portions of its orbit, and those intrinsic to the Moon’s contraction. In addition, impacts on the Moon also generate quakes. Information about all these events should give planetary scientists a big leg up on understanding more about the lunar interior structure.

The deployment of DAS and other science experiments will be part of the surface operations of the Artemis missions. It will be part of one of the proposed seven-month stays for astronaut teams. Although there is no specific planned date for seismometer deployment, it’s likely to take place no sooner than the mid-2030s. That’s after the planned missions to build shelters, deploy power stations, and other activities to create the lunar bases.

For More Information

A New Type of Seismic Sensor to Detect Moonquakes
Assessing the feasibility of Distributed Acoustic Sensing (DAS) for Moonquake Detection
Lunar Seismology: A Data and Instrumentation Review

The post Artemis Astronauts Will Deploy New Seismometers on the Moon appeared first on Universe Today.

I’ll write more about this tomorrow, perhaps, but here’s what I was going to put in tomorrow’s Nooz:

*One day after Columbia University’s President and some of its trustees testified before Congress on endemic antisemitism at the University, and after President Shafik promised to double down on antisemitism, the school has started arresting lots of pro-Palestinian demonstrators engaged in illegal protests.  I guess those nasty Republicans put the fear of God (literally) into Shafik, who doesn’t want to go the way of Liz Magill.

The authorities moved Thursday afternoon to quell a protest at Columbia University, arresting dozens of demonstrators who had constructed an encampment of about 50 tents on campus. The arrests, which drew a new crowd of students to support the protesters, came the day after university leaders pledged to Congress that they would crack down on unauthorized student protests tied to the war in Gaza.

Police officers, clad in riot gear and prepared with zip ties, began taking protesters into custody just before 1:30 p.m. as scores of demonstrators gathered in front of Butler Library. “Since you have refused to disperse, you will now be placed under arrest for trespassing,” a man repeatedly called through a loudspeaker. “If you resist arrest, you may face additional charges.”

The scene played out less than 24 hours after Columbia’s president, Nemat Shafik, and other top officials insisted to Congress that they would take a harder line in handling the protests that have embroiled campuses across the country since the Oct. 7 attack on Israel by Hamas. Leaders at two other elite schools, Harvard and the University of Pennsylvania, lost their jobs after similar appearances last year.

Here’s what else to know:

• Hundreds of students and others rallied with the protesters inside and outside of the school overnight and through the morning. “They can threaten us all they want with the police, but at the end of the day, it’s only going to lead to more mobilization,” said Maryam Alwan, a senior and pro-Palestinian organizer on campus, speaking from the tent encampment.

• Police officers loaded at least three buses with demonstrators, who cooperated as they were taken into custody, though other protesters shouted “Shame! Shame!” Organizers had said they expected to be arrested.

• Dr. Shafik angered some students and professors during her appearance before the House Committee on Education and the Workforce on Wednesday, when she largely conceded that she felt some of the common chants at pro-Palestinian protests were antisemitic. In a letter sent on Thursday afternoon as the arrests began, Dr. Shafik said she “took this extraordinary step because these are extraordinary circumstances.”

About time, I’d say.  Without punishment there is no deterrent, which is my own University’s problem with protestors like these. And foreign students are especially liable, as they could lose their visas if suspended (that’s why MIT didn’t arrest any of its protestors). Colleges are loath to suspend foreign students, or have them arrested, because foreign students pay pretty much the full fees at colleges, whereas Americans often get big breaks on tuition.

And, mirabile dictu, one of the students who has been both arrested and suspended (from Barnard), is Isra Hirsi, the daughter of none other than Congresswoman and notorious antisemite Ilhan “Follow the Benjamins” Omar. (Omar was in fact on the House committee that grilled the Columbia people.

Isra Hirsi, the daughter of Representative Ilhan Omar of Minnesota, is among several Barnard students who have been suspended for participating in a pro-Palestinian encampment at Columbia University.

The camp, which includes dozens of tents pitched on the campus’s South Lawn in protest against Israeli actions in Gaza, has created a standoff between administrators and students on the Ivy League campus. Dozens of students were arrested on Thursday, after the university notified them that they would be suspended if they refused to move and the students vowed to remain in place.

Ms. Hirsi posted on social media around 11:30 a.m. on Thursday that she was one of three students suspended so far for participating in the protest, which began on Wednesday, the day the university’s president, Nemat Shafik, appeared before Congress to discuss antisemitism on campus.

At the congressional hearing, Dr. Shafik told lawmakers that she would enforce rules about unauthorized protests and antisemitism. Ms. Omar, who is on the committee that held the hearing and who did not mention that her daughter was among the pro-Palestinian protesters, was one of several Democrats who questioned Ms. Shafik about her actions toward Palestinian and Muslim students.

Ms. Hirsi, 21, said on social media that she was an organizer with Columbia University Apartheid Divest, the student coalition that has been pushing the university to cut ties with companies that support Israel. Such divestment is the key demand of protesters in the encampment. She is also involved with the Columbia chapter of Students for Justice in Palestine, one of two student groups that was suspended in November for holding unauthorized protests.

“I have never been reprimanded or received any disciplinary warnings,” she wrote. “I just received notice that I am 1 of 3 students suspended for standing in solidarity with Palestinians facing a genocide.”

Ms. Hirsi is a junior majoring in sociology. Two other Barnard students, Maryam Iqbal, 18, a freshman, and Soph Dinu, 21, a junior majoring in religion, were also suspended, protest organizers said.

Who would have thought that testifying before a hostile group of Republicans in Congress would make college presidents straighten up and fly right? I disagree with the hostile treatment of Presidents, but it’s time to start enforcing the “time, place, and manner” aspects of protests, speech, and demonstrations. It’s also time to enforce behavior codes (and speech codes, if schools have them, which they shouldn’t) uniformly, for it was the lack of uniformity that got Liz Magill fired from Penn and started the process that resulted in Harvard’s Claudine Gay being let go.  My preference is the Chicago Free Expression principles, but those don’t allow you to say anything, anywhere, and at any time on campus.

Pro-Palestinian protestors have been coddled too long (even at the University of Chicago), and unless they get serious discipline from their colleges, they’ll just keep disrupting everything.  This is a lesson that Daniel Diermeier, Chancellor of Vanderbilt University, learned, perhaps from being Provost here first.  What a pity that threats like those of Congress are what make colleges reform and apply their rules uniformly!

Now if only the University of Chicago would listen. . .

The dwarf planet Ceres has some permanently dark craters that hold ice. Astronomers thought the ice was ancient when they were discovered, like in the moon’s permanently shadowed regions. But something was puzzling.

Why did some of these shadowed craters hold ice while others did not?

Ceres was first discovered in 1801 and was considered a planet. Later, it was thought to be the first asteroid ever discovered, since it’s in the main asteroid belt. Since then, our expanding knowledge has changed its definition: we now know it as a dwarf planet.

Even though it was discovered over 200 years ago, it’s only in the last couple of decades that we’ve gotten good looks at its surface features. NASA’s Dawn mission is responsible for most of our knowledge of Ceres’ surface, and it found what appeared to be ice in permanently shadowed regions (PSRs.)

New research shows that these PSRs are not actually permanent and that the ice they hold is not ancient. Instead, it’s only a few thousand years old.

The new research is titled “History of Ceres’s Cold Traps Based on Refined Shape Models,” published in The Planetary Science Journal. The lead author is Norbert Schorghofer, a senior scientist at the Planetary Science Institute.

“The results suggest all of these ice deposits must have accumulated within the last 6,000 years or less.”

Norbert Schorghofer, senior scientist, Planetary Science Institute.

Dawn captured its first images of Ceres while approaching the dwarf planet in January 2015. At that time, it was close enough to capture images as good as Hubble’s. Those images showed craters and a high-albedo site on the surface. Once captured by Ceres, Dawn followed a polar orbit with decreasing altitude. It eventually reached 375 km (233 mi) above the surface, allowing it to see the poles and surface in greater detail.

“For Ceres, the story started in 2016, when the Dawn spacecraft, which orbited around Ceres at the time, glimpsed into these permanently dark craters and saw bright ice deposits in some of them,” Schorghofer said. “The discovery back in 2016 posed a riddle: Many craters in the polar regions of Ceres remain shadowed all year – which on Ceres lasts 4.6 Earth years – and therefore remain frigidly cold, but only a few of them harbor ice deposits.”

As scientists continued to study Ceres, they made another discovery: its massive Solar System neighbours make it wobble.

“Soon, another discovery provided a clue why: The rotation axis of Ceres oscillates back and forth every 24,000 years due to tides from the Sun and Jupiter. When the axis tilt is high and the seasons strong, only a few craters remain shadowed all year, and these are the craters that contain bright ice deposits,” said lead author Schorghofer.

This figure from the research shows how Ceres’ obliquity has changed over the last 25,000 years. As the obliquity varies, sunlight reaches some crater floors that were thought to be PSRs. Image Credit: Schorghofer et al. 2023.

Researchers constructed digital elevation maps (DEMs) of the craters to uncover these facts. They wanted to find out how large and deep the shadows in the craters were, not just now but thousands of years ago. But that’s difficult to do since portions of these craters were in deep shadow when Dawn visited. That made it difficult to see how deep the craters were.

Robert Gaskell, also from the Planetary Science Institute, took on the task. He developed a new technique to create more accurate maps of the craters with data from Dawn’s sensitive Framing Cameras, contributed to the mission by Germany. With improved accuracy, these maps of the crater floors could be used in ray tracing to show sunlight penetrated the shadows as Ceres wobbled over thousands of years.

This figure from the study shows some of the DEMs the researchers developed for craters on Ceres. White regions represent sunlit areas, while the coloured contours represent PSRs for different axial tilts. Image Credit: Schorghofer et al. 2023.

The DEMs in the above image show that at 20 degrees obliquity, none of the craters are in permanent shadow. That means none of them have truly permanent PSRs. “A PSR starts to emerge in Bilwis crater at about 18°, and they emerge at lower obliquities at the other six study sites. This implies that the ice deposits are remarkably young,” the researchers write in their paper.

This figure from the research shows PSRs in the north-polar region of Ceres. The colour scale shows how oblique each crater is. The research shows that 14,000 years ago, none of these were PSRs, and the ice they hold now is only 6,000 years old. Image Credit: Schorghofer et al. 2023.

About 14,000 years ago, Ceres reached its maximum axial tilt. At that time, no craters were PSRs. Any ice in these craters would’ve been sublimated into space. “That leaves only one plausible explanation: The ice deposits must have formed more recently than that. The results suggest all of these ice deposits must have accumulated within the last 6,000 years or less. Considering that Ceres is well over 4 billion years old, that is a remarkably young age,” Schorghofer said.

So, where did the ice come from?

There must be some source if the ice is young and keeps reforming during maximum obliquity. The only plausible one is Ceres itself.

“Ceres is an ice-rich object, but almost none of this ice is exposed on the surface. The aforementioned polar craters and a few small patches outside the polar regions are the only ice exposures. However, ice is ubiquitous at shallow depths – as discovered by PSI scientist Tom Prettyman and his team back in 2017 – so even a small dry impactor could vaporize some of that ice.” Schorghofer said. “A fragment of an asteroid may have collided with Ceres about 6,000 years ago, which created a temporary water atmosphere. Once a water atmosphere is generated, ice would condense in the cold polar craters, forming the bright deposits that we still see today. Alternatively, the ice deposits could have formed by avalanches of ice-rich material. This ice would then survive in only the cold shadowed craters. Either way, these events were very recent on an astronomical time scale.”

There are other potential sources of water ice. Ceres has a very thin, transient water atmosphere. The water could come from cryovolcanic processes and then be trapped and frozen in shadowed regions.

Ceres also has a single cryovolcano: Ahuna Mons. It’s at least a couple hundred million years old and long dormant. There are dozens of other dormant potential cryovolcanoes, too. But these likely aren’t the water source.

There’s ample water ice at shallow levels in Ceres. If the dwarf planet erodes over time, mass-wasting could expose and release water that freezes in the craters. “The few ice deposits that have been detected spectroscopically outside the polar regions are indeed often associated with landslides, and the sunlit portion of the ice deposit in Zatik crater is best explained by a recent mass wasting event,” the authors explain.

Ceres has been through a lot. As an ancient protoplanet that’s survived to this day, it holds important clues to the Solar System. Though its craters don’t hold ancient ice like once thought, deeper study is revealing the dwarf planet’s true nature.

“The ice deposits in the Cerean PSRs indicate an active water cycle; ice is either repeatedly captured and lost or frequently exposed, or both,” the authors conclude.

The post Ice Deposits on Ceres Might Only Be a Few Thousand Years Old appeared first on Universe Today.

Cocaine and morphine hijacked neural responses in the brains of mice, which resulted in them consuming less food and water

Cosmic rays are high-energy particles accelerated to extreme velocities approaching the speed of light. It takes an extremely powerful event to send these bits of matter blazing through the Universe. Astronomers theorize that cosmic rays are ejected by supernova explosions that mark the death of supergiant stars. But recent data collected by the Fermi Gamma-ray space telescope casts doubt on this production method for cosmic rays, and has astronomers digging for an explanation.

It’s not easy to tell where a cosmic ray comes from. Most cosmic rays are hydrogen nuclei, others are protons, or free-flying electrons. These are charged particles, meaning that every time they come across other matter in the Universe with a magnetic field, they change course, causing them to zig-zag through space.

The direction a cosmic ray comes from when it hits Earth, then, is not likely the direction it started in.

But there are ways to indirectly track down their origin. One of the more promising methods is by observing gamma rays (which do travel in straight lines, thankfully).

When cosmic rays bump into other bits of matter, they produce gamma rays. So when a supernova goes off and sends cosmic rays out into the Universe, it should also send a gamma-ray signal letting us know it’s happening.

That’s the theory, anyway.

But the evidence hasn’t matched expectations. Studies of old, distant supernovas show some gamma ray production occurring, but not as much as predicted. Astronomers explained away the missing radiation as a result of the supernovas’ age and distance. But in 2023, the Fermi telescope captured a bright new supernova occurring nearby. Named SN 2023ixf, the supernova went off just 22 million light-years away in a galaxy called Messier 101 (better known as the ‘Pinwheel Galaxy’). And yet again, gamma rays were conspicuously absent.

NASA Goddard.

“Astrophysicists previously estimated that supernovae convert about 10% of their total energy into cosmic ray acceleration,” said Guillem Martí-Devesa, University of Trieste. “But we have never observed this process directly. With the new observations of SN 2023ixf, our calculations result in an energy conversion as low as 1% within a few days after the explosion. This doesn’t rule out supernovae as cosmic ray factories, but it does mean we have more to learn about their production.”

So where is all the missing gamma radiation?

It’s possible that interstellar material around the exploding star could have blocked gamma rays from reaching the Fermi telescope. But it might also mean that astronomers need to look for alternative explanations for the production of cosmic rays.

Nobody likes a good mystery better than astronomers, and digging into the missing gamma radiation could eventually tell us a whole lot more about cosmic rays and where they come from.

Astronomers plan to study SN 2023ixf in other wavelengths to improve their models of the event, and will of course keep an eye out for the next big supernova, in an effort to understand what is going on.

The most recent gamma-ray data from SN 2023ixf will be published in Astronomy and Astrophysics in a paper led by Martí-Devesa.

The post The Mystery of Cosmic Rays Deepens appeared first on Universe Today.