Science – Page 31

Man suffers chemical burn that lasted months after squeezing limes

health, medical cases, NEJM, phytophotodermatitis, rash, Science, skin / Beth Washington / November 27, 2024

If Margaritaville were a real place, it should definitely keep a few dermatologists on hand.

In a case of an oft-overlooked food preparation risk, a 40-year-old man showed up to an allergy clinic in Texas with a severe, burning rash on both his hands that had two days earlier. A couple of days later, it blistered. And a few weeks after that, the skin darkened and scaled. After several months, the skin on his hands finally returned to normal.

The culprit: lime juice and sunlight.

It turns out that just before developing the nasty skin eruption, the man had manually squeezed a dozen limes, then headed to an outdoor soccer game without applying sunscreen. His doctors diagnosed the man’s rash as a classic case of phytophotodermatitis, according to a case report published Wednesday in the New England Journal of Medicine.

The condition is caused by toxic substances found in plants (phyto) that react with UV light (photo) to cause a burning, blistering, scaling, pigmented skin condition (dermatitis).

Specifically, the toxic chemicals are furocoumarins, which are found in some weeds and also a range of plants used in food. Those include celery, carrot, parsley, fennel, parsnip, lime, bitter orange, lemon, grapefruit, and sweet orange. Furocoumarins include chemicals with linear structures, psoralens, and angular structures, called angelicins, though not all of them are toxic.

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What fossilized dino feces can tell us about their rise to dominance

coprolites, dinosaurs, evolutionary biology, food webs, fossilized feces, Jurassic, paleontology, Science, Triassic / Shannon Garcia / November 27, 2024

Paleontologists have long puzzled over how the dinosaurs—originally relatively small and of minor importance to the broader ecosystem—evolved to become the dominant species some 30 million years later. Fossilized feces and vomit from dinosaurs might hold important clues to how and why this evolutionary milestone came about, according to a new paper published in the journal Nature.

Co-author Martin Qvarnström, an evolutionary biologist with Uppsala University in Sweden, and his collaborators studied trace fossils known as bromalites, a designation that includes coprolites as well as vomit or other fossilized matter from an organism’s digestive tract. As previously reported, coprolites aren’t quite the same as paleofeces, which retain a lot of organic components that can be reconstituted and analyzed for chemical properties. Coprolites are fossils, so most organic components have been replaced by mineral deposits like silicate and calcium carbonates.

For archaeologists keen on learning more about the health and diet of past populations—as well as how certain parasites evolved in the evolutionary history of the microbiome—coprolites and paleofeces can be a veritable goldmine of information. For instance, in 2021 we reported on an analysis of preserved paleo-poop revealing that ancient Iron Age miners in what is now Austria were fond of beer and blue cheese.

If a coprolite contains bone fragments, chances are the animal who excreted it was a carnivore, and tooth marks on those fragments can tell us something about how the animal may have eaten its prey. The size and shape of coprolites can also yield useful insights. If a coprolite is spiral-shaped, for instance, it might have been excreted by an ancient shark, since some modern fish (like sharks) have spiral-shaped intestines.

A tale of two models

Excavations in the Late Triassic locality at Lisowice, Poland. The site yielded a large number of coprolites of predators and herbivores. Credit: Krystian Balanda

Qvarnström et al. were keen to test two competing hypotheses about the dinosaurs’ rise to dominance from the Late Triassic Period (237 million to 201 million years ago) to the onset of the Jurassic Period between 201 million to 145 million years ago. “No single hypothesis seems capable of explaining the rise of dinosaurs fully and critical questions about how dinosaurs established their dynasty on land remain largely unanswered,” the authors wrote about their research objectives.

One hypothesis cites evolutionary competition—the traditional “competitive replacement” model—as a driving factor, in which dinosaurs were better equipped to survive thanks to superior physiologies, anatomical adaptations, and feeding habits. Alternatively the “opportunistic replacement” model suggests that the dinosaurs were better able to adapt to a rapidly changing environment brought about by random processes—volcanic eruptions, climate change, or other catastrophic events that led to the decline and/or extinction of other species.

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Teaching a drone to fly without a vertical rudder

Biomechanics, birds, Drones, engineering, flight, mechanical engineering, Science / Beth Washington / November 27, 2024

We can get a drone to fly like a pigeon, but we needed to use feathers to do it.

Pigeons manage to get vertical without using a vertical tail. Credit: HamidEbrahimi

Most airplanes in the world have vertical tails or rudders to prevent Dutch roll instabilities, a combination of yawing and sideways motions with rolling that looks a bit like the movements of a skater. Unfortunately, a vertical tail adds weight and generates drag, which reduces fuel efficiency in passenger airliners. It also increases the radar signature, which is something you want to keep as low as possible in a military aircraft.

In the B-2 stealth bomber, one of the very few rudderless airplanes, Dutch roll instabilities are dealt with using drag flaps positioned at the tips of its wings, which can split and open to make one wing generate more drag than the other and thus laterally stabilize the machine. “But it is not really an efficient way to solve this problem,” says David Lentink, an aerospace engineer and a biologist at the University of Groningen, Netherlands. “The efficient way is solving it by generating lift instead of drag. This is something birds do.”

Lentink led the study aimed at better understanding birds’ rudderless flight mechanics.

Automatic airplanes

Birds flight involves near-constant turbulence—“When they fly around buildings, near trees, near rocks, near cliffs,” Lentink says. The leading hypothesis on how they manage this in a seemingly graceful, effortless manner was suggested by a German scientist named Franz Groebbels. He argued that birds’ ability relied on their reflexes. When he held a bird in his hands, he noticed that its tail would flip down when the bird was pitched up and down, and when the bird was moved left and right, its wings also responded to movement by extending left and right asymmetrically. “Another reason to think reflexes matter is comparing this to our own human locomotion—when we stumble, it is a reflex that saves us from falling,” Lentink claims.

Groebbels’ intuition about birds’ reflexes being responsible for flight stabilization was later backed by neuroscience. The movements of birds’ wings and muscles were recorded and found to be proportional to the extent that the bird was pitched or rolled. The hypothesis, however, was extremely difficult to test with a flying bird—all the experiments aimed at confirming it have been done on birds that were held in place. Another challenge was determining if those wing and tail movements were reflexive or voluntary.

“I think one pretty cool thing is that Groebbels wrote his paper back in 1929, long before autopilot systems or autonomous flight were invented, and yet he said that birds flew like automatic airplanes,” Lentink says. To figure out if he was right, Lentink and his colleagues started with the Groebbels’s analogy but worked their way backward—they started building autonomous airplanes designed to look and fly like birds.

Reverse-engineering pigeons

The first flying robot Lentink’s team built was called the Tailbot. It had fixed wings and a very sophisticated tail that could move with five actuated degrees of freedom. “It could spread—furl and unfurl—move up and down, move sideways, even asymmetrically if necessary, and tilt. It could do everything a bird’s tail can,” Lentink explains. The team put this robot in a wind tunnel that simulated turbulent flight and fine-tuned a controller that adjusted the tail’s position in response to changes in the robot’s body position, mimicking reflexes observed in real pigeons.

“We found that this reflexes controller that managed the tail’s movement worked and stabilized the robot in the wind tunnel. But when we took it outdoors, results were disappointing. It actually ended up crashing,” Lentink says. Given that relying on a morphing tail alone was not enough, the team built another robot called PigeonBot II, which added pigeon-like morphing wings.

Each wing could be independently tucked or extended. Combined with the morphing tail and nine servomotors—two per wing and five in the tail—the robot weighed around 300 grams, which is around the weight of a real pigeon. Reflexes were managed by the same controller that was modified to manage wing motions as well.

To enable autonomous flight, the team fitted the robot with two propellers and an off-the-shelf drone autopilot called Pixracer. The problem with the autopilot, though, was that it was designed for conventional controls you use in quadcopter drones. “We put an Arduino between the autopilot and the robot that translated autopilot commands to the morphing tail and wings’ motions of the robot,” Lentink says.

The Pigeon II passed the outdoor flying test. It could take off, land, and fly entirely on its own or with an operator issuing high-level commands like go up, go down, turn left, or turn right. Flight stabilization relied entirely on bird-like reflexes and worked well. But there was one thing electronics could not re-create: their robots used real pigeon feathers. “We used them because with current technology it is impossible to create structures that are as lightweight, as stiff, and as complex at the same time,” Lentink says.

Feathery marvels

Birds’ feathers appear simple, but they really are extremely advanced pieces of aerospace hardware. Their complexity starts with nanoscale features. “Feathers have 10-micron 3D hooks on their surface that prevent them from going too far apart. It is the only one-sided Velcro system in the world. This is something that has never been engineered, and there is nothing like this elsewhere in nature,” Lentink says. Those nanoscale hooks, when locked in, can bear loads reaching up to 20 grams.

Then there are macroscale properties. Feathers are not like aluminum structures that have one bending stiffness, one torque stiffness, and that’s it. “They are very stiff in one direction and very soft in another direction, but not soft in a weak way—they can bear significant loads,” Lentink says.

His team attempted to make artificial feathers with carbon fiber, but they couldn’t create anything as lightweight as a real feather. “I don’t know of any 3D printer that could start with 10-micron nanoscale features and work all the way up to macro-scale structures that can be 20 centimeters long,” Lentink says. His team also discovered that pigeon’s feathers could filter out a lot of turbulence perturbations on their own. “It wasn’t just the form of the wing,” Lentink claims.

Lentink estimates that a research program aimed at developing aerospace materials even remotely comparable to feathers could take up to 20 years. But does this mean his whole concept of using reflex-based controllers to solve rudderless flight hangs solely on successfully reverse-engineering a pigeon’s feather? Not really.

Pigeon bombers?

The team thinks it could be possible to build airplanes that emulate the way birds stabilize rudderless flight using readily available materials. “Based on our experiments, we know what wing and tail shapes are needed and how to control them. And we can see if we can create the same effect in a more conventional way with the same types of forces and moments,” Lentink says. He suspects that developing entirely new materials with feather-like properties would only become necessary if the conventional approach bumps into some insurmountable roadblocks and fails.

“In aerospace engineering, you’ve got to try things out. But now we know it is worth doing,” Lentink claims. And he says military aviation ought to be the first to attempt it because the risk is more tolerable there. “New technologies are often first tried in the military, and we want to be transparent about it,” he says. Implementing bird-like rudderless flight stabilization in passenger airliners, which are usually designed in a very conservative fashion, would take a lot more research, “It may take easily take 15 years or more before this technology is ready to such level that we’d have passengers fly with it,” Lentink claims.

Still, he says there is still much we can learn from studying birds. “We know less about bird’s flight than most people think we know. There is a gap between what airplanes can do and what birds can do. I am trying to bridge this gap by better understanding how birds fly,” Lentink adds.

Science Robotics, 2024. DOI: 10.1126/scirobotics.ado4535

Jacek Krywko is a freelance science and technology writer who covers space exploration, artificial intelligence research, computer science, and all sorts of engineering wizardry.

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Licking this “lollipop” will let you taste virtual flavors

augmented reality, extended reality, haptic interfaces, Human-computer interface, Science, virtual reality / 9u50fv / November 26, 2024

Demonstrating lollipop user interface to simulate taste in virtual and augmented reality environments. Credit: Lu et al, 2024/PNAS

Virtual reality (VR) technology has long sought to incorporate the human senses into virtual and mixed-reality environments. In addition to sight and sound, researchers have been trying to add the sensation of human touch and smell via various user interfaces, as well as taste. But the latter has proved to be quite challenging. A team of Hong Kong scientists has now developed a handheld user interface shaped like a lollipop capable of re-creating several different flavors in a virtual environment, according to a new paper published in the Proceedings of the National Academy of Sciences (PNAS).

It’s well established that human taste consists of sweet, salty, sour, bitter, and umami—five basic flavors induced by chemical stimulation of the tongue and, to a lesser extent, in parts of the pharynx, larynx, and epiglottis. Recreating those sensations in VR has resulted in a handful of attempts at a flavor user interface, relying on such mechanisms as chemical, thermal, and electrical stimulation, as well as iontophoresis.

The chemical approach usually involves applying flavoring chemicals directly onto the tongue, but this requires room for bulk storage of said chemicals, and there is a long delay time that is not ideal for VR applications. Thermal variations applied directly to the tongue can stimulate taste sensations but require a complicated system incorporating a cooling subsystem and temperature sensors, among other components.

The most mainstream method is electrical stimulation, in which the five basic flavors are simulated by varying the frequency, intensity, and direction of electrical signals on the tongue. But this method requires placing electrode patches on or near the tongue, which is awkward, and the method is prone to taste biases.

So Yiming Liu of City University of Hong Kong and co-authors opted to work with iontophoresis, in which stable taste feedback is achieved by using ions flowing through biologically safe hydrogels to transport flavor chemicals. This method is safe, requires low power consumption, allows for precise taste feedback, and offers a more natural human-machine interface. Liu et al. improved on recent advances in this area by developing their portable lollipop-shaped user interface device, which also improves flavor quality and consistency.

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NASA awards SpaceX a contract for one of the few things it hasn’t done yet

dragonfly, falcon heavy, launch, NASA, nuclear, planetary science, Saturn, Science, solar system, Space, spacex, Titan / Kelly Newman / November 26, 2024

Notably, the Dragonfly launch was one of the first times United Launch Alliance has been eligible to bid its new Vulcan rocket for a NASA launch contract. NASA officials gave the green light for the Vulcan rocket to compete head-to-head with SpaceX’s Falcon 9 and Falcon Heavy after ULA’s new launcher had a successful debut launch earlier this year. With this competition, SpaceX came out on top.

A half-life of 88 years

NASA’s policy for new space missions is to use solar power whenever possible. For example, Europa Clipper was originally supposed to use a nuclear power generator, but engineers devised a way for the spacecraft to use expansive solar panels to capture enough sunlight to produce electricity, even at Jupiter’s vast distance from the Sun.

But there are some missions where this isn’t feasible. One of these is Dragonfly, which will soar through the soupy nitrogen-methane atmosphere of Titan. Saturn’s largest moon is shrouded in cloud cover, and Titan is nearly 10 times farther from the Sun than Earth, so its surface is comparatively dim.

The Dragonfly mission, seen here in an artist’s concept, is slated to launch no earlier than 2027 on a mission to explore Saturn’s moon Titan. Credit: NASA/JHUAPL/Steve Gribben

Dragonfly will launch with about 10.6 pounds (4.8 kilograms) of plutonium-238 to fuel its power generator. Plutonium-238 has a half-life of 88 years. With no moving parts, RTGs have proven quite reliable, powering spacecraft for many decades. NASA’s twin Voyager probes are approaching 50 years since launch.

The Dragonfly rotorcraft will launch cocooned inside a transit module and entry capsule, then descend under parachute through Titan’s atmosphere, which is four times denser than Earth’s. Finally, Dragonfly will detach from its descent module and activate its eight rotors to reach a safe landing.

Once on Titan, Dragonfly is designed to hop from place to place on numerous flights, exploring environments rich in organic molecules, the building blocks of life. This is one of NASA’s most exciting, and daring, robotic missions of all time.

After launching from NASA’s Kennedy Space Center in Florida in July 2028, it will take Dragonfly about six years to reach Titan. When NASA selected the Dragonfly mission to begin development in 2019, the agency hoped to launch the mission in 2026. NASA later directed Dragonfly managers to target a launch in 2027, and then 2028, requiring the mission to change from a medium-lift to a heavy-lift rocket.

Dragonfly has also faced rising costs NASA blames on the COVID-19 pandemic and supply chain issues and an in-depth redesign since the mission’s selection in 2019. Collectively, these issues caused Dragonfly’s total budget to grow to $3.35 billion, more than double its initial projected cost.

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Things aren’t looking good for infamous CEO of “health care terrorists”

corruption, health, health care, health care industry, hospitals, Malta, ralph de la torre, Science, steward / Shannon Garcia / November 26, 2024

Earlier this year, a Maltese magistrate concluded a four-year investigation into the matter and recommended that Ernst and de la Torre be charged with money laundering, criminal association, and corruption of public officials, including the nation’s former prime minister, Joseph Muscat, the Globe reports.

Meanwhile, new allegations of domestic dealings continue to come to light. In a separate investigative story Monday, the Globe reported that Steward executives used Steward-owned malpractice insurer TRACO “like a piggy bank.” The Panama-based TRACO was supposed to work like an independent insurer for the hospital chain; Steward would pay TRACO malpractice insurance premiums on behalf of its doctors and the pooled money would be used to litigate and pay out claims. But, instead of paying premiums, Steward gave TRACO IOUs. By the end of 2023, TRACO’s accounting records showed $99 million in outstanding loans, most owed by Steward, and $176 million in “accounts receivable,” also mostly owed by Steward.

With Steward now in bankruptcy, insurance coverage for health care providers is now in question, as are payouts to patients who were harmed by Steward’s care. The Globe noted the case of Yasmany Sosa, whose 35-year-old wife, Yanisey Rodriguez, died a preventable death after giving birth at Steward North Shore Medical Center in Florida in September 2022. Steward agreed to a $4 million settlement with Sosa in March, but the money hasn’t appeared, leaving Sosa in limbo and struggling.

“They killed my wife, that’s for starters. Second of all, they destroyed my family,” Sosa told the Globe through a translator. “This has all become a bunch of loopholes, legal strategies. This really is very difficult for me… I’ve already lost everything.”

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Raw milk recalled for containing bird flu virus, California reports

bird flu, California, H5N1, health, Infectious disease, influenza, pasteurization, raw milk, Science / 9u50fv / November 25, 2024

Pasteurization

The milk-related risk of H5N1 is only from raw milk; pasteurized milk does not contain live virus and is safe to drink. Pasteurization, which heats milk to a specific temperature for a specified amount of time, kills a variety of bacteria and viruses, including bird flu. Influenza viruses, generally, are considered susceptible to heat treatments because they have an outer layer called an envelope, which can be destabilized by heat. Studies that have specifically looked at the effectiveness of heat-killing treatments against H5N1 have repeatedly found that pasteurization effectively inactivates the virus.

The advent of pasteurization is considered a public health triumph. Its adoption of a safe milk supply contributed to a dramatic reduction in infant deaths in the early 20th century. Before that, milkborne infections—including human and bovine tuberculosis, brucellosis, salmonellosis, streptococcal infections, diphtheria, and “summer diarrhea”—were common killers of infants.

As such, public health officials have long advised people against consuming raw milk, which has no evidence-based health benefits. Raw milk consumption, meanwhile, is linked to higher rates of outbreaks from pathogens including Salmonella, Listeria monocytogenes, toxin-producing E. coli, Brucella, Campylobacter, and many other bacteria.

Risky drinking

Since H5N1 was found spreading among dairy cows in March, health experts have warned about the additional risk of consuming raw milk. Still, consumption of raw milk has continued, and surprisingly increased, as supporters of the dangerous practice have accused health officials of “fearmongering.”

When the retail sampling of Raw Farm’s milk came back positive, the California Department of Food and Agriculture (CDFA) conducted testing at the company’s locations, which were negative for the virus. The CDFA will now begin testing Raw Farm’s milk for bird flu twice a week.

The recalled milk has lot code 20241109 and a “best by” date of November 27, 2024, printed on the packaging.

“Drinking or accidentally inhaling raw milk containing bird flu virus may lead to illness,” California’s public health department said. “In addition, touching your eyes, nose, or mouth with unwashed hands after touching raw milk with bird flu virus may also lead to infection.”

Some US dairy workers who contracted the virus from infected cows reported having had milk splash in their eyes and face. A common symptom of H5N1 infections in humans during the dairy outbreak has been conjunctivitis, aka eye inflammation.

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$300 billion pledge at COP29 climate summit a “paltry sum”

climate change, COP29, Policy, Science, syndication / Shannon Garcia / November 25, 2024

The world’s most important climate talks were pulled back from the brink of collapse after poorer countries reluctantly accepted a finance package of “at least” $300 billion a year from wealthy nations after bitter negotiations.

Fears about stretched budgets around the world and the election of Donald Trump as US president, who has described climate change as a “hoax,” drove the developing countries into acceptance of the slightly improved package after Sunday 2: 30 am local time in Baku.

The UN COP29 climate summit almost collapsed twice throughout Saturday evening and into the early hours of Sunday morning, as vulnerable nations walked out of negotiations and India objected stridently.

As the gavel came down, India’s lead negotiator, Neelesh Shah, leapt to his feet to ask to take the floor, and when he was ignored made a furious timeout gesture above his head and led his team on to the stage in protest.

Speaking from the floor, Indian delegation member Chandni Raina said the country was “extremely disappointed” by the abrupt passage of the agreement, adding: “This was stage-managed.”

“It is a paltry sum,” she said. “I am sorry to say that we cannot accept it. We seek a much higher ambition from developed countries.” The agreement was “nothing more than an optical illusion,” she added.

The broadside was followed by objections from Bolivia, Chile, and Nigeria, who were told by COP29 President Mukhtar Babayev that their statements were noted. Smaller nations, such as Malawi, Fiji, and the Maldives, joined in the grievance.

Simon Stiell, head of the UN climate change arm, said the new goal was an “insurance policy for humanity, amid worsening climate impacts hitting every country” but added that it was “no time for victory laps.”

European Union climate commissioner Wopke Hoekstra tried to assure disappointed smaller nations, saying he was “confident we will reach the $1.3 trillion” economists say developing countries need to shift to green energy and cope with climate change.

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How physics moves from wild ideas to actual experiments

experiments, Features, neutrinos, particles, Science / Shannon Garcia / November 25, 2024

Science often accommodates audacious proposals.

Instead of using antennas, could we wire up trees in a forest to detect neutrinos? Credit: Claire Gillo/PhotoPlus Magazine/Future via Getty Images

Neutrinos are some of nature’s most elusive particles. One hundred trillion fly through your body every second, but each one has only a tiny chance of jostling one of your atoms, a consequence of the incredible weakness of the weak nuclear force that governs neutrino interactions. That tiny chance means that reliably detecting neutrinos takes many more atoms than are in your body. To spot neutrinos colliding with atoms in the atmosphere, experiments have buried 1,000 tons of heavy water, woven cameras through a cubic kilometer of Antarctic ice, and planned to deploy 200,000 antennas.

In a field full of ambitious plans, a recent proposal by Steven Prohira, an assistant professor at the University of Kansas, is especially strange. Prohira suggests that instead of using antennas, we could detect the tell-tale signs of atmospheric neutrinos by wiring up a forest of trees. His suggestion may turn out to be impossible, but it could also be an important breakthrough. To find out which it is, he’ll need to walk a long path, refining prototypes and demonstrating his idea’s merits.

Prohira’s goal is to detect so-called ultra-high-energy neutrinos. Each one of these tiny particles carries more than fifty million times the energy released by uranium during nuclear fission. Their origins are not fully understood, but they are expected to be produced by some of the most powerful events in the Universe, from collapsing stars and pulsars to the volatile environments around the massive black holes at the centers of galaxies. If we could detect these particles more reliably, we could learn more about these extreme astronomical events.

Other experiments, like a project called GRAND, plan to build antennas to detect these neutrinos, watching for radio signals that come from their reactions with our atmosphere. However, finding places to place these antennas can be a challenge. Motivated by this experiment, Prohira dug up old studies by the US Army that suggested an alternative: instead of antennas, use trees. By wrapping a wire around each tree, army researchers found that the trees were sensitive to radio waves, which they hoped to use to receive radio signals in the jungle. Prohira argues that the same trick could be useful for neutrino detection.

Crackpot or legit science?

People suggest wacky ideas every day. Should we trust this one?

At first, you might be a bit suspicious. Prohira’s paper is cautious on the science but extremely optimistic in other ways. He describes the proposal as a way to help conserve the Earth’s forests and even suggests that “a forest detector could also motivate the large-scale reforesting of land, to grow a neutrino detector for future generations.”

Prohira is not a crackpot, though. He has a track record of research in detecting neutrinos via radio waves in more conventional experiments, and he even received an $800,000 MacArthur genius grant a few years ago to support his work.

More generally, studying particles from outer space often demands audacious proposals, especially ones that make use of the natural world. Professor Albrecht Karle works on the IceCube experiment, an array of cameras that detect neutrinos whizzing through a cubic kilometer of Antarctic ice.

“In astroparticle physics, where we often cannot build the entire experiment in a laboratory, we have to resort to nature to help us, to provide an environment that can be used to build a detector. For example, in many parts of astroparticle physics, we are using the atmosphere as a medium, or the ocean, or the ice, or we go deep underground because we need a shield because we cannot construct an artificial shield. There are even ideas to go into space for extremely energetic neutrinos, to build detectors on Jupiter’s moon Europa.”

Such uses of nature are common in the field. India’s GRAPES experiments were designed to measure muons, but they have to filter out anything that’s not a muon to do so. As Professor Sunil Gupta of the Tata Institute explained, the best way to do that was with dirt from a nearby hill.

“The only way we know you can make a muon detector work is by filtering out other radiation […] so what we decided is that we’ll make a civil structure, and we’ll dump three meters of soil on top of that, so those three meters of soil could act as a filter,” he said.

The long road to an experiment

While Prohira’s idea isn’t ridiculous, it’s still just an idea (and one among many). Prohira’s paper describing the idea was uploaded to arXiv.org, a pre-print server, in January. Physicists use pre-print servers to give access to their work before it’s submitted to a scientific journal. That gives other physicists time to comment on the work and suggest revisions. In the meantime, the journal will send the work out to a few selected reviewers, who are asked to judge both whether the paper is likely to be correct and whether it is of sufficient interest to the community.

At this stage, reviewers may find problems with Prohira’s idea. These may take the form of actual mistakes, such as if he made an error in his estimates of the sensitivity of the detector. But reviewers can also ask for more detail. For example, they could request a more extensive analysis of possible errors in measurements caused by the different shapes and sizes of the trees.

If Prohira’s idea makes it through to publication, the next step toward building an actual forest detector would be convincing the larger community. This kind of legwork often takes place at conferences. The International Cosmic Ray Conference is the biggest stage for the astroparticle community, with conferences every two years—the next is scheduled for 2025 in Geneva. Other more specialized conferences, like ARENA, focus specifically on attempts to detect radio waves from high-energy neutrinos. These conferences can offer an opportunity to get other scientists on board and start building a team.

That team will be crucial for the next step: testing prototypes. No matter how good an idea sounds in theory, some problems only arise during a real experiment.

An early version of the GRAPES experiment detected muons by the light they emit passing through tanks of water. To find how much water was needed, the researchers did tests, putting a detector on top of a tank and on the bottom and keeping track of how often both detectors triggered for different heights of water based on the muons that came through randomly from the atmosphere. After finding that the tanks of water would have to be too tall to fit in their underground facility, they had to find wavelength-shifting chemicals that would allow them to use shorter tanks and novel ways of dissolving these chemicals without eroding the aluminum of the tank walls.

“When you try to do something, you run into all kinds of funny challenges,” said Gupta.

The IceCube experiment has a long history of prototypes going back to early concepts that were only distantly related to the final project. The earliest, like the proposed DUMAND project in Hawaii, planned to put detectors in the ocean rather than ice. BDUNT was an intermediate stage, a project that used the depths of Lake Baikal to detect atmospheric neutrinos. While the detectors were still in liquid water, the ability to drive on the lake’s frozen surface made BDUNT’s construction easier.

In a 1988 conference, Robert March, Francis Halzen, and John G. Learned envisioned a kind of “solid state DUMAND” that would use ice instead of water to detect neutrinos. While the idea was attractive, the researchers cautioned that it would require a fair bit of luck. “In summary, this is a detector that requires a number of happy accidents to make it feasible. But if these should come to pass, it may provide the least expensive route to a truly large neutrino telescope,” they said.

In the case of the AMANDA experiment, early tests in Greenland and later tests at the South Pole began to provide these happy accidents. “It was discovered that the ice was even more exceptionally clear and has no radioactivities—absolutely quiet, so it is the darkest and quietest and purest place on Earth,” said Karle.

AMANDA was much smaller than the IceCube experiment, and theorists had already argued that to see cosmic neutrinos, the experiment would need to cover a cubic kilometer of ice. Still, the original AMANDA experiment wasn’t just a prototype; if neutrinos arrived at a sufficient rate, it would spot some. In this sense, it was like the original LIGO experiment, which ran for many years in the early 2000s with only a minimal chance of detecting gravitational waves, but it provided the information needed to perform an upgrade in the 2010s that led to repeated detections. Similarly, the hope of pioneers like Halzen was that AMANDA would be able to detect cosmic neutrinos despite its prototype status.

“There was the chance that, with the knowledge at the time, one might get lucky. He certainly tried,” said Karle.

Prototype experiments often follow this pattern. They’re set up in the hope that they could discover something new about the Universe, but they’re built to at least discover any unexpected challenges that would stop a larger experiment.

Major facilities and the National Science Foundation

For experiments that don’t need huge amounts of funding, these prototypes can lead to the real thing, with scientists ratcheting up their ambition at each stage. But for the biggest experiments, the governments that provide the funding tend to want a clearer plan.

Since Prohira is based in the US, let’s consider the US government. The National Science Foundation has a procedure for its biggest projects, called the Major Research Equipment and Facilities Construction program. Since 2009, it has had a “no cost overrun” policy. In the past, if a project ended up costing more than expected, the NSF could try to find additional funding. Now, projects are supposed to estimate beforehand how the cost could increase and budget extra for the risk. If the budget goes too high anyway, projects should compensate by reducing scope, shrinking the experiment until it falls under costs again.

To make sure they can actually do this, the NSF has a thorough review process.

First, the NSF expects that the scientists proposing a project have done their homework and have already put time and money into prototyping the experiment. The general expectation is that about 20 percent of the experiment’s total budget should have been spent testing out the idea before the NSF even starts reviewing it.

With the prototypes tested and a team assembled, the scientists will get together to agree on a plan. This often means writing a report to hash out what they have in mind. The IceCube team is in the process of proposing a second generation of their experiment, an expansion that would cover more ice with detectors and achieve further scientific goals. The team recently finished the third part of a Technical Design Report, which details the technical case for the experiment.

After that, experiments go into the NSF’s official experiment design process. This has three phases, conceptual design, preliminary design, and final design. Each phase ends with a review document summarizing the current state of the plans as they firm up, going from a general scientific case to a specific plan to put an experiment in a specific place. Risks are estimated in detail and list estimates of how likely risks are and how much they will cost, a process that sometimes involves computer simulations. By the end of the process, the project has a fully detailed plan and construction can begin.

Over the next few years, Prohira will test out his proposal. He may get lucky, like the researchers who dug into Antarctic ice, and find a surprisingly clear signal. He may be unlucky instead and find that the complexities of trees, with different spacings and scatterings of leaves, makes the signals they generate unfit for neutrino science. He, and we, cannot know in advance which will happen.

That’s what science is for, after all.

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After Russian ship docks to space station, astronauts report a foul smell

iss, russia, Science, Space / Shannon Garcia / November 24, 2024

Russian space program faces ongoing challenges

Zak reported that the cosmonauts aboard the Russian segment of the station donned protective equipment, and activated an extra air-scrubbing system aboard their side of the facility. On the US segment of the station, NASA astronaut Don Pettit said he smelled something akin to “spray paint.”

As of Sunday afternoon, NASA said there were no concerns for the crew, and that astronauts were working to open the hatch between the Poisk module and the Progress spacecraft. Attached to the space station in 2009, Poisk is a small element that connects to one of four docking ports on the Russian segment of the station.

It was not immediately clear what caused the foul odor to emanate from the Progress vehicle, however previous Russian vehicles have had leaks while in space. Most recently, in February 2023, a Progress vehicle attached to the station lost pressurization in its cooling system.

Facing financial and staffing pressures due to the ongoing Russian war against Ukraine, the main Russian space corporation, Roscosmos, has faced a series of technical problems as it has sought to fly people and supplies to the International Space Station in recent years.

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Survivors mark 20th anniversary of deadly 2004 tsunami

Science / Beth Washington / November 24, 2024

In the wee hours of December 26, 2004, a massive 9.2 earthquake occurred in the Indian Ocean, generating an equally massive tsunami that caused unprecedented devastation to 14 countries and killing more than 230,000. Twenty years later, National Geographic has revisited one of the deadliest natural disasters in recorded history with a new documentary: Tsunami: Race Against Time. The four-part series offers an in-depth account of the tsunami’s destructive path, told from the perspectives of those who survived, as well as the scientists, journalists, doctors, nurses, and everyday heroes who worked to save as many as possible.

Geophysicist Barry Hirshorn—now with Scripps Institution of Oceanography at the University of California, San Diego—was on duty at the Pacific Tsunami Warning Center in Hawaii that day (3 PM on Christmas Day local time). His pager went off, indicating that seismic waves had set off a seismometer in Australia, and Hirshorn rushed to the control room to locate the quake’s epicenter with his colleague, Stuart Weinstein.

They initially pegged the quake at 8.5 magnitude. (It was later upgraded to 8.9 and subsequently to a whopping 9.2 to 9.3 magnitude.) But despite its strength, they initially did not think the quake would generate a tsunami, at least in the Pacific. And such events were incredibly rare in the Indian Ocean.

Hirshorn and Weinstein also lacked any real-time sea level data that would have told them that a massive amount of water had been displaced by the movement of two key tectonic plates (the India and Burma plates). Four hours later, the first tsunami waves hit Indonesia, Thailand, India, Sri Lanka, and the Maldives, leaving a path of destruction and death in their wake.

Geophysicist Barry Hirshorn on the lack of an tsunami early warning system for the Indian Ocean. Credit: National Geographic

What sets this new documentary apart is the emphasis on the survivors’ harrowing stories. Veteran surfer David Lines, for example, was living in Banda Aceh at the time with his wife Nurma. They managed to outrun the tsunami by car, but Nurma lost 30 family members. Journalist and videographer Denny Montgomery faced a similar situation, racing against time to rescue his mother. Zenny Suryawan watched his family get swept away by the tsunami, surviving by clinging to debris. A young mother in Khao Lan was separated from her infant son and had nearly given up hope when she finally found him alive at a nearby hospital.

Survivors mark 20th anniversary of deadly 2004 tsunami Read More »

What delusions can tell us about the cognitive nature of belief

cognitive dissonance, Mental Health, Science, syndication / DJ Henderson / November 24, 2024

Natalie also recalled other beliefs, including that she was dead (known as Cotard delusion), which she did not share with clinicians at the time. She noted that she entertained this idea due to the failure of other explanations to account for her strange experiences and an idea from a television show.

Natalie said she eventually dismissed this idea as implausible while still holding other delusional ideas. This suggests that belief evaluation may involve different thresholds for different delusions. It also highlights the private nature of some delusions.

Across all of her delusions, Natalie described her active involvement in trying to explain and manage her experiences. She reported considering different explanations and testing these by seeking further information. For example, she asked questions of the people she thought were her in-laws. This suggests a surprisingly similar approach to how we typically form beliefs.

Natalie recalled the influence of television and movies on her ideas. She also recalled how she elaborated on her delusions, once formed, based on information in her surroundings.

These features challenge theories that delusions simply arise from anomalous sensory data. They instead highlight the role of the individual’s search for meaning and social context, as well as the subsequent impact of delusions on perception and thinking.

Implications

As a case study, Natalie’s experiences are not necessarily representative of all people who experience delusions or postpartum psychosis. However, Natalie’s case presents informative features that theories of delusions need to account for.

In particular, Natalie’s personalized insights highlight the critical role of the individual in actively trying to understand their experiences and bestow meaning. This is opposed to just passively accepting beliefs in response to anomalous sensory data or neuropsychological deficits. This suggests psychological therapies may be useful in treating psychosis, in combination with other treatments, in some cases.

More generally, Natalie’s account reveals commonalities between delusions and ordinary beliefs and supports the view that delusions can be understood in terms of cognitive processes across the stages of normal belief formation that we identified.

While there remain challenges in investigating delusions, further study may offer insights into the underpinnings of everyday belief and, in turn, of ourselves.

Michael Connors, Conjoint Senior Lecturer in Psychiatry, UNSW Sydney, and Peter W Halligan, Hon Professor of Neuropsychology, Cardiff University. This article is republished from The Conversation under a Creative Commons license. Read the original article.

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