NASA's Juno spacecraft has made the closest approach to Jupiter's tantalizing, icy moon Europa in more than 20 years. From a report: Juno on Thursday zipped within 222 miles (357 kilometers) of Europa, thought to have an ocean flowing beneath its thick frozen crust, raising the possibility of underwater life. Scientists hope to get lucky and observe possible water plumes shooting from the surface of Europa, close in size to Earth's moon. "We have to be at the right place at just the right time, but if we are so fortunate, it's a home run for sure," Juno's chief scientist, Scott Bolton of Southwest Research Institute in San Antonio, said in a statement. John Bordi, deputy mission manager at NASA's Jet Propulsion Laboratory, expected the spacecraft to go "screaming by pretty fast," with a relative velocity of almost 15 miles per second (23.6 kilometers per second). Pictures should be available by Friday, NASA said. The latest observations will help NASA plan for its Europa Clipper mission, due to launch in 2024. The European Space Agency also plans close encounters with its Jupiter Icy Moons Explorer, or Juice, lifting off next year.

Japan -- which has strict laws against the use of marijuana -- should consider approving the import, manufacture and use of medicines derived from cannabis, subject to the same approval process as pharmaceuticals, a health ministry panel said. From a report: At the same time, the country should do more to discourage recreational use of the plant, the committee said in its findings following a meeting Thursday. Possession of cannabis is illegal but not its use; the panel recommended that unsanctioned use should also be made a criminal offense. While Canada, several US states and some European countries have decriminalized the recreational use of marijuana, penalties for possession, cultivation and sales of the substance in Japan can carry prison sentences of as long as 10 years. Just 1.4% of the population have ever tried cannabis, according to one study with 2017 data. Celebrities caught for possession often become front-page news.

An anonymous reader quotes a report from Motherboard: Everyone wants to be able to just zap a bug and have it go away. But now, thanks to a recent development from Ildar Rakhmatulin, a research associate at Heriot-Watt University interested in machine learning and engineering, this dream is now a reality. In the study -- which was conducted last year but published in Oriental Insects last week -- Rakhmatulin and his co-authors used a laser insect control device automated with machine vision to perform a series of experiments on domiciliary cockroaches. They were able to not only detect cockroaches at high accuracy but also neutralize and deter individual insects at a distance up to 1.2 meters. This is a follow-up of sorts to earlier projects, in which he used a Raspberry Pi and lasers to zap mosquitoes. However, for this project, Rakhmatulin used a different kind of computer which allowed for more precision in detecting the bug.

"I started using a Jetson Nano that allowed me to use deep learning technologies with higher accuracy to detect an object," Rakhmatulin explained. The Jetson Nano is a small computer that can run machine learning algorithms. The computer processes a digital signal from two cameras to determine the cockroach's position. It transmits that information to a galvanometer (a machine that measures electric current), which changes the direction of the laser to shoot the target. According to the paper, Rakhmatulin tried this configuration at different power levels for the laser. At a lower power level, he found that he could influence the behavior of roaches by simply triggering their flight response with a laser; this way, they could potentially be trained to not shelter in a particular dark area. At a higher power level, the cockroaches were effectively "neutralized," in the paper's language -- in other words, killed. "I use very cheap hardware and cheap technology and it's open source," Rakhmatulin said. "All sources are uploaded in my GitHub and see how to do it and use it. If it can damage cockroaches, it can also damage other pests in agriculture."

It's not quite ready for household use though. "It's not recommended because it's a little dangerous," Rakhmatulin said. "Lasers can damage not only cockroaches but your eyes."

You can view a video of the device in action here.

North Korea has begun a mass Covid-19 vaccination campaign in its border areas, according to South Korea's spy agency, becoming one of the world's final countries to embark on such a national rollout. From a report: North Korea and Eritrea, in east Africa, were the only remaining countries that hadn't started widespread vaccination distribution, the World Health Organization has said. After rejecting millions of doses from other countries last year, North Korea admitted to its first nationwide Covid-19 outbreak in May and declared victory in August. Then, earlier this month, leader Kim Jong Un said Covid-19 vaccines would be distributed starting in November. He cited findings from the country's antiepidemic experts that North Koreans who contracted Covid-19 in May and June would experience a decline in their antibody response starting in October.

During a Wednesday briefing to South Korean lawmakers, Seoul's spy agency said North Korea had begun distributing vaccines, though it didn't specify in which border areas. The lawmakers who were briefed didn't say where the vaccines had come from or when they were first distributed. Repeated lockdowns suggest North Korea hasn't eradicated the virus, the spy agency told lawmakers. Considering some recent resumption of flights and train operations between China and North Korea, it is most likely that China is supplying the vaccines, said Hong Min, of the Seoul-based Korea Institute for National Unification, a government-funded think tank.

The pharmaceutical companies Biogen and Eisai said this week that a drug they are developing for Alzheimer's disease had slowed the rate of cognitive decline in a large late-stage clinical trial. From a report: The strong results boost the drug's chances of winning approval and offer renewed hope for a class of Alzheimer's drugs that have repeatedly failed or generated mixed results. The positive data also offer Biogen a second chance after the company's disastrous rollout of another Alzheimer's drug, Aduhelm. That medication won regulatory approval last year despite little evidence that it could slow cognitive decline, received only sharply limited coverage by Medicare and has proved to be a commercial failure.

The results appear stronger for the new medication, lecanemab. Cognitive decline in the group of volunteers who received lecanemab was reduced by 27 percent compared with the group who received a placebo in the clinical trial, which enrolled nearly 1,800 participants with mild cognitive impairment or mild Alzheimer's disease, the companies said. The trial of lecanemab, which is administered via intravenous infusion, was the largest to date to test whether clearing the brain of plaques formed by the accumulation of a protein called amyloid could slow the progression of Alzheimer's disease. Aduhelm is designed to work in a similar way.

An anonymous reader quotes a report from Science Magazine: In 2020, Ranga Dias, a physicist at the University of Rochester, and his colleagues published a sensational result in Nature, featured on its cover. They claimed to have discovered a room-temperature superconductor: a material in which electric current flows frictionlessly without any need for special cooling systems. Although it was just a speck of carbon, sulfur, and hydrogen forged under extreme pressures, the hope was that someday the material would lead to variants that would enable lossless electricity grids and inexpensive magnets for MRI machines, maglev railways, atom smashers, and fusion reactors. Faith in the result is now evaporating. On Monday Nature retracted the study, citing data issues other scientists have raised over the past 2 years that have undermined confidence in one of two key signs of superconductivity Dias's team had claimed. "There have been a lot of questions about this result for a while," says James Hamlin, an experimental condensed matter physicist at the University of Florida. But Jorge Hirsch, a theoretical physicist at the University of California, San Diego (UCSD), and longtime critic of the study, says the retraction does not go far enough. He believes it glosses over what he says is evidence of scientific misconduct. "I think this is a real problem," he says. "You cannot leave it as, 'Oh, it's a difference of opinion.'"

The retraction was unusual in that Nature editors took the step over the objection of all nine authors of the paper. "We stand by our work, and it's been verified experimentally and theoretically," Dias says. Ashkan Salamat, a physicist at the University of Nevada, Las Vegas, and another senior member of the collaboration, points out the retraction does not question the drop in electric resistance -- the most important part of any superconductivity claim. He adds, "We're confused and disappointed in the decision-making by the Nature editorial board." The retraction comes even as excitement builds for the class of superconducting materials called hydrides, which includes the carbonaceous sulfur hydride (CSH) developed by Dias's team. Under pressures greater than at the center of the Earth, hydrogen is thought to behave like a superconducting metal. Adding other elements to the hydrogen -- creating a hydride structure -- can increase the "chemical pressure," reducing the need for external pressure and making superconductivity reachable in small laboratory vises called diamond anvil cells. As Lilia Boeri, a theoretical physicist at the Sapienza University of Rome, puts it, "These hydrides are a sort of realization of metallic hydrogen at slightly lower pressure."

In 2015, Mikhail Eremets, an experimental physicist at the Max Planck Institute for Chemistry, and colleagues reported the first superconducting hydride: a mix of hydrogen and sulfur that, under enormous pressures, exhibited a sharp drop in electrical resistance at a critical temperature (Tc) of 203 K (-70C). That was nowhere near room temperature, but warmer than the Tc for most superconducting materials. Some theorists thought adding a third element to the mix would give researchers a new variable to play with, enabling them to get closer to ambient pressures -- or room temperatures. For the 2020 Nature paper, Dias and colleagues added carbon, crushed the mix in a diamond anvil cell, and heated it with a laser to create a new substance. They reported that tests showed a sharp drop in resistance at a Tc of 288 K (15C) -- roughly room temperature -- and a pressure of 267 gigapascals, about 75% of the pressure at the center of the Earth. But in a field that has seen many superconducting claims come and go, a drop in resistance alone is not considered sufficient. The gold standard is to provide evidence of another key attribute of superconductors: their ability to expel an applied magnetic field when they cross Tc and become superconducting. Measuring that effect in a diamond anvil cell is impractical, so experimentalists working with hydrides often measure a related quantity called "magnetic susceptibility." Even then they must contend with tiny wires and samples, immense pressures, and a background magnetic signal from metallic gaskets and other experimental components. "It's like you're trying to see a star when the Sun is out," Hamlin says. "The study's magnetic susceptibility data were what led to the retraction," reports Science. "The team members reported that a susceptibility signal emerged after they had subtracted a background signal, but they did not include raw data. The omission frustrated critics, who also complained that the team relied on a 'user-defined' background -- an assumed background rather than a measured one. But Salamat says relying on a user-defined background is customary in high-pressure physics because the background is so hard to measure experimentally."

Dias and Salamat posted a paper to arXiv in 2021 containing the raw susceptibility data and purported to explain how the background was subtracted, but it "raised more questions than it answered," says Brad Ramshaw, a quantum materials physicist at Cornell University. "The process of going from the raw data to the published data was incredibly opaque."

Hirsch accused the data of being "fabricated," noting suspicious similarities to data in a 2009 paper on superconductivity in europium under high pressures. It too was later retracted.

NASA's DART spacecraft successfully slammed into a distant asteroid at hypersonic speed on Monday in the world's first test of a planetary defense system, designed to prevent a potential doomsday meteorite collision with Earth. From a report: Humanity's first attempt to alter the motion of an asteroid or any celestial body played out in a NASA webcast from the mission operations center outside Washington, D.C., 10 months after DART was launched. The livestream showed images taken by DART's camera as the cube-shaped "impactor" vehicle, no bigger than a vending machine with two rectangular solar arrays, streaked into the asteroid Dimorphos, about the size of a football stadium, at 7:14 p.m. EDT (2314 GMT) some 6.8 million miles (11 million km) from Earth. The $330 million mission, some seven years in development, was devised to determine if a spacecraft is capable of changing the trajectory of an asteroid through sheer kinetic force, nudging it off course just enough to keep Earth out of harm's way. Whether the experiment succeeded beyond accomplishing its intended impact will not be known until further ground-based telescope observations of the asteroid next month. But NASA officials hailed the immediate outcome of Monday's test, saying the spacecraft achieved its purpose.

Noam Izenberg, a researcher at the Johns Hopkins University's applied physics laboratory, is making a case for sending a crewed mission to examine Venus en route to Mars. "Venus gets a bad rap because it's got such a difficult surface environment," said Izenberg in a report presented at the International Astronautical Congress in Paris last week. "The current Nasa paradigm is moon-to-Mars. We're trying to make the case for Venus as an additional target on that pathway." The Guardian reports: There are notable downsides. Walking on the surface would be an unsurvivable experience, so astronauts would have to gaze down at the planet from the safety of their spacecraft in a flyby mission. In its favor, however, Venus is significantly closer, making a return mission doable in a year, compared with a potentially three-year roundtrip to Mars. A flyby would be scientifically valuable and could provide crucial experience of a lengthy deep-space mission as a precursor to visiting Mars, according to a report presented at the International Astronautical Congress (IAC) in Paris last week.

Izenberg said there were practical arguments for incorporating a Venus flyby into the crewed Mars landing that Nasa hopes to achieve by the late 2030s. Although the planet is in the "wrong" direction, performing a slingshot around Venus -- known as a gravity assist - could reduce the travel time and the fuel required to get to the red planet. That would make a crewed flyby trip to Venus a natural stepping stone towards Nasa's ultimate goal. "You'd be learning about how people work in deep space, without committing yourself to a full Mars mission," he said. "And it's not just going out into the middle of nowhere -- it would have a bit of cachet as you'd be visiting another planet for the first time." "We need to understand how we can get out of the cradle and move into the universe," he added.

There is also renewed scientific interest in Venus. The discovery of thousands of exoplanets raises the question of how many might be habitable, and scientists want to understand how and why Venus, a planet so similar to our own in size, mass and distance from the sun, ended up with infernal surface conditions. Izenberg said a Venus flyby "doesn't yet have traction" in the broader space travel community, although there are advocates within Nasa, including its chief economist, Alexander Macdonald, who led the IAC session. Of course, there are those who push back against such an idea. "It's really not a nice place to go. It's a hellish environment and the thermal challenges for a human mission would be quite considerable," said Prof Andrew Coates, a space scientist at UCL's Mullard space science laboratory.

He said Venus was rightly a focus of scientific exploration, but that "a human flyby really wouldn't add very much."

A beautiful blue flaw in a gem-quality diamond from Botswana is actually a tiny fragment of Earth's deep interior -- and it suggests our planet's mantle contains oceans' worth of water. Scientific American: The flaw, technically called an inclusion, looks like a fish eye: a deep blue center surrounded by a white haze. But it's really a pocket of the mineral ringwoodite from 660 kilometers down, at the boundary between the upper and lower mantle. This is just the second time scientists have found this mineral in a chunk of crystal from this zone, and the sample is the only one of its kind currently known to science. The last example was destroyed during an attempt to analyze its chemistry.

[...] The discovery indicates that this very deep zone of Earth is soggy, with vast amounts of water locked up tight within the minerals there. Though this water is chemically bound to the minerals' structure and doesn't flow around like an actual ocean, it does likely play an important role in how the mantle melts. This in turn affects big-picture geology, such as plate tectonics and volcanic activity. For example, water could contribute to the development of areas of mantle upwelling known as plumes, which are hotspots for volcanoes.

The stunning bit of diamond-encased mantle was discovered by Tingting Gu, a mineral physicist now at Purdue University, who was at the time doing research at the Gemological Institute of America. Her job was to study rare inclusions found in diamonds. Inclusions are undesirable for jewelry because they cloud a diamond's sparkle. But they're often interesting to scientists because they trap bits of the environment where the diamond formed millennia earlier. The vast majority of diamonds form between about 150 to 200 km below Earth's surface. But a handful come from much deeper. It is often difficult to pinpoint exactly how deep, but the new sample was remarkably accommodating on that front, Gu and her colleagues reported on Monday in a study published in Nature Geoscience. Ringwoodite can only form at incredibly high pressures. It is not found in Earth's crust, but it is sometimes seen trapped in meteorites that underwent major cosmic trauma. In Earth's mantle, ringwoodite exists at the pressures present down to 660 km.

Most mission scientists would wince at the thought of their spacecraft being smashed to smithereens. But for those behind Nasa's Dart probe, anything short of total destruction will be chalked up as a failure. From a report: The $330m spacecraft is due to slam head-on into an asteroid about 11m kilometres above the Indian Ocean soon after midnight on Monday. The impact, at nearly seven kilometres a second, will obliterate the half-tonne probe, all in the name of planetary defence. Not that Dimorphos, the asteroid in question, poses any threat to humanity. The Dart, or double asteroid redirection test, is an experiment, the first mission ever to assess whether asteroids can be deflected should one ever be found on a collision course with Earth. A well-placed nudge could avert Armageddon, or so the thinking goes, and spare humans the same fate as the dinosaurs.

"It's a very complicated game of cosmic billiards," said Prof Alan Fitzsimmons, an astronomer and member of the Nasa Dart investigation team at Queen's University Belfast. "What we want to do is use as much energy [as we can] from Dart to move the asteroid." With telescopes constantly scanning the skies, scientists hope to have some notice if an asteroid were ever to present a major threat. "If we are able to see far enough in advance and know that an asteroid might be a problem, pushing it out of the way will be much safer than the big Hollywood idea of blowing it up," said Catriona McDonald, a PhD student at Warwick University. The Dart mission launched from Vandenberg space force base in November last year. On Monday night, mission controllers will hand control to Dart's software and let the probe steer itself into oblivion.

Using the Canadian Hydrogen Intensity Mapping Experiment (CHIME), astronomers have detected a new radio pulsar in a binary system with a massive non-degenerate companion star. The discovery of the pulsar, which received designation PSR J2108+4516, was detailed in a paper published September 14 on the arXiv pre-print server. Phys.Org reports: Pulsars are highly magnetized, rotating neutron stars emitting a beam of electromagnetic radiation. They are usually detected in the form of short bursts of radio emission; however, some of them are also observed via optical, X-ray and gamma-ray telescopes. Now, an international team of astronomers led by Bridget C. Andersen of McGill University in Montreal, Canada, reports the finding of a new rare type of a binary pulsar -- hosting a massive companion. The detection was made using CHIME, a radio telescope possessing a very wide field of view, large collecting area and high sensitivity across the 400-800 MHz range.

All in all, the team acquired almost three years of near-daily CHIME/Pulsar observations of PSR J2108+4516 extending from October 20, 2018 to September 3, 2021. Profile drifts over pulse phase indicated that the pulsar was experiencing significant acceleration from orbiting with a massive binary companion. The observations of PSR J2108+4516 revealed that it has a spin period of about 0.58 seconds and orbital period of 269 days. The orbital eccentricity was found to be at a level of approximately 0.09 and the pulsar's characteristic age was estimated to be around 2.1 million years. The surface magnetic field of PSR J2108+4516 was measured to be some 1.2 trillion Gauss.

When it comes to the companion object, the results suggest that its mass should be between 11.7 and 113 solar masses. The study found that the companion is a bright OBe star, known as EM* UHA 138, located at a distance of about 10,600 light years. The researchers estimate that the mass of this star is most likely between 17 and 23 solar masses. Summing up the results, the astronomers underlined that PSR J2108+4516 is the sixth young pulsar with a massive non-degenerate companion so far detected. The authors of the paper added that PSR J2108+4516 may serve as a rare laboratory for the exploration of massive star winds and circumstellar disks.

Psychiatrists in Brussels can now prescribe free visits to cultural venues to people suffering from depression, stress or anxiety. The Guardian reports: Delphine Houba, a Brussels deputy mayor in charge of culture, believes the project is the first of its kind in Europe. The first objective is to reinforce access to culture after the pressured days of lockdown, she told the Observer. "I want everybody back in our cultural institutions... but we know that, even before Covid, for some people it [was] not easy to open the door of a museum, they don't feel at ease, they don't think that it's for them. And I really want to show that cultural venues are for everybody." The second goal, she said, is to give doctors "a new tool in the healing process." The young socialist politician was inspired by a similar project in Canada, where doctors have been issuing prescriptions to the Montreal Museum of Fine Arts since 2018.

In Brussels, the pilot project is running for six months, involving five museums that are directly under the control of city authorities. These include the city's history museum, a centre for contemporary art, and the fashion and lace museum. Patients may also discover the sewer museum, which allows them to stroll 10 meters underground along the banks of the Senne, the hidden river of Brussels, largely paved over in the 19th century. Or they could explore the collection of outfits belonging to the Manneken Pis, the statue of a peeing boy that has become a symbol of Belgium's self-deprecating humor

"Anything could have therapeutic value if it helps people get a good feeling and get in touch with themselves," said Dr Johan Newell, a psychiatrist at Brugmann University Hospital, which is taking part in the pilot scheme. He expects museum prescriptions would suit people suffering from depression, anxiety, autism spectrum disorders, psychosis and bipolar disorder. "I think almost anyone could benefit from it," he said. "It would probably be more adapted for people who are already a little bit further on in the recovery process," rather than those who are severely ill, he said. Museum prescriptions, Newell stressed, were a voluntary addition to medication, psychotherapy, individual or group therapy, as well as exercise, healthy eating and other forms of relaxation. "It's just one extra tool that could help people get out of the house: to resocialize, reconnect with society." Newell suggests that the pilot could eventually be expanded to include other museums, cinemas, hospitals and groups of patients.

The Artemis I rocket will not have its third launch attempt on Tuesday as planned due to concerns over Tropical Storm Ian making its way toward Cuba and Florida. CNN reports: After meeting on Saturday morning, NASA's Artemis team decided to forgo the September 27 launch opportunity and is now preparing the mega moon rocket stack for rollback. "On Tuesday, Tropical Storm Ian is forecast to be moving north through the eastern Gulf of Mexico as a hurricane, just off the southwest coast of Florida. A cold front will also be draped across northern Florida pushing south," said CNN Meteorologist Haley Brink.

"The combination of these weather factors will allow for increased rain chances across much of the Florida peninsula on Tuesday, including the Cape Canaveral area. Showers and thunderstorms are forecast to be numerous and widespread across the region. Tropical storm-force winds from Ian could also arrive as early as Tuesday night across central Florida." Meanwhile, the Space Launch System rocket and Orion spacecraft continue to sit on the launchpad at Kennedy Space Center in Florida.

Team members continue to monitor the weather as they make a decision about when to roll the rocket stack back into the Vehicle Assembly Building at Kennedy. NASA will receive information from the US Space Force, the National Hurricane Center and the National Oceanic and Atmospheric Administration to inform their decision. [...] The rocket stack can remain at the pad and withstand winds up to 85 miles per hour (74.1 knots). If the stack needs to roll back into the building, it can handle sustained winds less than 46 miles per hour (40 knots). On Friday, the Artemis team said that October 2 was a backup launch date. But it's unlikely that a new launch date will be set until the rollback decision has been made.

Saul Kripke, a math prodigy and pioneering logician whose revolutionary theories on language qualified him as one of the 20th century's greatest philosophers, died on Sept. 15 in Plainsboro, N.J. He was 81. The New York Times reports: His death, at Penn Medicine Princeton Medical Center, was caused by pancreatic cancer, according to Romina Padro, director of the Saul Kripke Center at the City University of New York, where Professor Kripke had been a distinguished professor of philosophy and computer science since 2003 and had capped a career exploring how people communicate. Professor Kripke's classic work, "Naming and Necessity," first published in 1972 and drawn from three lectures he delivered at Princeton University in 1970 before he was 30, was considered one of the century's most evocative philosophical books.

"Kripke challenged the notion that anyone who uses terms, especially proper names, must be able to correctly identify what the terms refer to," said Michael Devitt, a distinguished professor of philosophy who recruited Professor Kripke to the City University Graduate Center in Manhattan. "Rather, people can use terms like 'Einstein,' 'springbok,' perhaps even 'computer,' despite being too ignorant or wrong to provide identifying descriptions of their referents," Professor Devitt said. "We can use terms successfully not because we know much about the referent but because we're linked to the referent by a great social chain of communication."

The Pulitzer Prize-winning historian Taylor Branch, writing in The New York Times Magazine in 1977, said Professor Kripke had "introduced ways to distinguish kinds of true statements -- between statements that are 'possibly' true and those that are 'necessarily' true." "In Professor Kripke's analysis," he continued, "a statement is possibly true if and only if it is true in some possible world -- for example, 'The sky is blue' is a possible truth, because there is some world in which the sky could be red. A statement is necessarily true if it is true in all possible worlds, as in 'The bachelor is an unmarried man.'"

An anonymous reader quotes a report from the Daily Beast: Luis Eduardo Garrido couldn't wait to test out his colleague's newest creation. Garrido, a psychology and methodology researcher at Pontificia Universidad Catolica Madre y Maestra in the Dominican Republic, drove two hours between his university's campuses to try a virtual reality experience that was designed to treat obsessive-compulsive disorder and different types of phobias. But a couple of minutes after he put on the headset, he could tell something was wrong. "I started feeling bad," Garrido told The Daily Beast. He was experiencing an unsettling bout of dizziness and nausea. He tried to push through but ultimately had to abort the simulation almost as soon as he started. "Honestly, I don't think I lasted five minutes trying out the application," he said.

Garrido had contracted cybersickness, a form of motion sickness that can affect users of VR technology. It was so severe that he worried about his ability to drive home, and it took hours for him to recover from the five-minute simulation. Though motion sickness has afflicted humans for thousands of years, cybersickness is a much newer condition. While this means that many of its causes and symptoms are understood, other basic questions -- like how common cybersickness is, and whether there are ways to fully prevent it -- are only just starting to be studied. After Garrido's experience, a colleague told him that only around 2 percent of people feel cybersickness. But at a presentation for prospective students, Garrido watched as volunteers from the audience walked to the front of an auditorium to demo a VR headset -- only to return shakily to their seats. "I could see from afar that they were getting sweaty and kind of uncomfortable," he recalled. "I said to myself, 'Maybe I'm not the only one.'"

As companies like Meta (nee Facebook) make big bets that augmented reality and virtual reality technology will go mainstream, the tech industry is still trying to figure out how to better recruit users to the metaverse, and get them to stay once there. But experts worry that cybersickness could derail these plans for good unless developers find some remedies soon. "The issue is actually something of a catch-22: In order to make VR more accessible and affordable, companies are making devices smaller and running them on less powerful processors," adds the report. "But these changes introduce dizzying graphics -- which inevitably causes more people to experience cybersickness."

"At the same time, a growing body of research suggests cybersickness is vastly more pervasive than previously thought -- perhaps afflicting more than half of all potential users." When Garrido conducted his own study of 92 people, the results indicated that more than 65 percent of people experienced symptoms of cybersickness -- a sharp contrast to the 2 percent estimate Garrido had been told.

He says that these results should be concerning for developers. "If people have this type of bad experience with something, they're not going to try it again," Garrido said.

Citing McDonald's shelved meat-free burger trial and a 70% dip in Beyond Meat's stock, The Guardian suggests plant-based meats may not interest Americans as much as investors thought. From the report: Getting meat eaters in the US to adopt plant-based alternatives has proven a challenge. Beyond Meat, which produces a variety of plant-based products, including imitations of ground beef, burgers, sausages, meatballs and jerky, has had a rough 12 months, with its stock dipping nearly 70%. Multiple chains that partnered with the company, including McDonald's, have quietly ended trial launches. In August, the company laid off 4% of its workforce after a slowdown in sales growth. Last week, its chief operating officer was reportedly arrested for biting another man on the nose during a road rage confrontation. It's a dramatic reversal of fortune. Just two years ago, Beyond Meat, its competitor Impossible Foods and the plant-based meat industry at large seemed poised to start a food revolution.

For a time, Wall Street went vegetarian. In 2019 Beyond Meat was valued at over $10 billion, more than Macy's or Xerox. The most bullish investors believed that plant-based meat would make up 15% of all meat sales by 2030. But the reality of Americans' interest in plant-based meat has proven more complicated than investors thought, and the adoption of meat alternatives has been slower than what was once hoped. Today Beyond Meat is valued at just over $900 million. The sobering story is similar to those experienced by many new ventures that see exhilarating hype after a flood of Silicon Valley venture capital cash, fueled by excitement about innovation. Bill Gates backed Beyond Meat, and a number of venture capital firms that typically invest in tech startups funneled money to startups making plant-based meat. Even the meat industry's biggest players have, ironically, invested in companies coming up with plant-based meat. While eating plant-based meat (or no meat at all) has been shown to be the most effective thing individual consumers can do to fight climate change, "consumers seem hesitant to adapt their behavior when the environment -- not their health or wallets -- is the sole beneficiary," reports The Guardian. "Despite the increasing alarm over climate change, the number of Americans who are vegetarian or vegan has remained relatively stable over the last 20 years."

"Even when participants in a study conducted at Purdue University in Indiana were given information about the carbon footprint of meat production, participants were more likely to go with regular meat over a plant-based alternative."

An anonymous reader quotes a report from Ars Technica: In January this year, an undersea volcano in Tonga produced a massive eruption, the largest so far this century. The mixing of hot volcanic material and cool ocean water created an explosion that sent an atmospheric shockwave across the planet and triggered a tsunami that devastated local communities and reached as far as Japan. The only part of the crater's rim that extended above water was reduced in size and separated into two islands. A plume of material was blasted straight through the stratosphere and into the mesosphere, over 50 km above the Earth's surface. We've taken a good look at a number of past volcanic eruptions and studied how they influence the climate. But those eruptions (most notably that of Mount Pinatubo) all came from volcanoes on land. Hunga Tonga may be the largest eruption we've ever documented that took place under water, and the eruption plume contained unusual amounts of water vapor -- so much of it that it actually got in the way of satellite observations at some wavelengths. Now, researchers have used weather balloon data to reconstruct the plume and follow its progress during two circuits around the globe.

Your vocabulary word of the day is radiosonde, which is a small instrument package and transmitter that can be carried into the atmosphere by a weather balloon. There are networks of sites where radiosondes are launched as part of weather forecasting services; the most relevant ones for Hunga Tonga are in Fiji and Eastern Australia. A balloon from Fiji was the first to take instruments into the eruption plume, doing so less than 24 hours after Hunga Tonga exploded. That radiosonde saw increasing levels of water as it climbed through the stratosphere from 19 to 28 kilometers of altitude. The water levels had reached the highest yet measured at the top of that range when the balloon burst, bringing an end to the measurements. But shortly after, the plume started showing up along the east coast of Australia, which again registered very high levels of water vapor. Again, water reached to 28 km in altitude but gradually settled to lower heights over the next 24 hours.

The striking thing was how much of it there was. Compared to normal background levels of stratospheric water vapor, these radiosondes were registering 580 times as much water even two days after the eruption, after the plume had some time to spread out. There was so much there that it still stood out as the plume drifted over South America. The researchers were able to track it for a total of six weeks, following it as it spread out while circling the Earth twice. Using some of these readings, the researchers estimated the total volume of the water vapor plume and then used the levels of water present to come up with a total amount of water put into the stratosphere by the eruption. They came up with 50 billion kilograms. And that's a low estimate, because, as mentioned above, there was still water above the altitudes where some of the measurements stopped. The recent findings appear in a new study published in the journal Science.

A pair of researchers who previously identified what may be the first known interstellar meteor to impact Earth have now presented evidence of a second object that could have originated beyond the solar system, before it burned up in our planet's skies and potentially fell to the surface, according to a new study. Motherboard reports: Amir Siraj, a student in astrophysics at Harvard University, and astronomer Avi Loeb, who serves as Harvard's Frank B. Baird Jr. Professor of Science, suggest that a fast-moving meteor that burst into a fireball hundreds of miles off the coast of Portugal on March 9, 2017, is an "additional interstellar object candidate" that they call interstellar meteor 2 (IM2) in a study posted to the preprint server arXiv this week. The paper has not been peer-reviewed. In addition to their potential origin beyond the solar system, these objects appear to be extraordinarily robust, as they rank as the first- and third-highest meteors in material strength in a NASA catalog that has collected data about hundreds of fireballs.

"We don't have a large enough sample to say how much stronger interstellar objects are than solar system objects, but we can say that they are stronger," Siraj said in an email. "The odds of randomly drawing two objects in the top 3 out of 273 is 1 in 10 thousand. And when we look at the specific numbers relative to the distribution of objects, we find that the Gaussian odds are more like 1 in a million." This makes IM2 "an outlier in material strength," Loeb added in a follow-up call with Siraj. "To us, it means that the source is different from planetary systems like the solar system."

Loeb has attracted widespread attention in recent years over his speculation that the first interstellar object ever identified, known as 'Oumuamua, was an artifact of alien technology. Spotted in 2017, 'Oumuamua sped through the solar system and was up to a quarter-mile in scale, making it much larger than the interstellar meteor candidates identified by Siraj and Loeb, which are a few feet across. Loeb's claims of an artificial origin for 'Oumuamua have provoked substantial pushback from many scientists who do not consider a technological explanation to be likely. Loeb also thinks these interstellar meteor candidates could be alien artifacts, though he and Siraj present a mind-boggling natural explanation for the strangely robust objects in the study: The meteors may be a kind of interstellar shrapnel produced by the explosions of large stars, called supernovae. [...] Loeb, of course, is keeping his mind open. "We don't say, necessarily, that it is artificial," Loeb said in the call, referring to the supernovae explanation. But, he added, "obviously, there is a possibility that a spacecraft was designed to sustain such harsh conditions as passing through the Earth's atmosphere, so we should allow for that."

An anonymous reader quotes a report from Scientific American: Vultures are hard birds for humans to love. They are an obligate scavenger, meaning they get all their food from already dead prey -- and that association has cast them as a harbinger of death since ancient times. But in reality, vultures are nature's flying sanitation crew. And new research adds to that positive picture by detailing these birds' role in a surprising process: mitigating greenhouse gas emissions. With their impressive vision and the range they can cover in their long, soaring flights, the 22 species of vultures found around the world are often the first scavengers to discover and feed on a carcass. This cleanup provides a vital service to both ecosystems and humans: it keeps nutrients cycling and controls pathogens that could otherwise spread from dead animals to living ones.

Decaying animal bodies release greenhouse gases, including carbon dioxide and methane. But most of these emissions can be prevented if vultures get to the remains first, a new study in Ecosystem Services shows. It calculates that an individual vulture eats between 0.2 and one kilogram (kg) of carcass per day, depending on the vulture species. Left uneaten, each kg of naturally decomposing carcass emits about 0.86 kg of CO2 equivalent. This estimate assumes that carcasses not eaten by vultures are left to decay. But many carcasses are composted or buried by humans, which result in more emissions than natural decay, so vulture consumption can avert even more emissions when replacing those methods. The avoided emissions may not sound like much, but multiply those estimates by the estimated 134 million to 140 million vultures around the world, and the number becomes more impressive: tens of millions of metric tons of emissions avoided per year.

But this ecosystem service is not evenly distributed around the world. It occurs mostly in the Americas, says the study's lead author Pablo Plaza, a biologist at the National University of Comahue in Argentina. Three species found only in the Americas -- the Black, Turkey and Yellow-headed vultures -- are responsible for 96 percent of all vulture-related emissions mitigation worldwide, Plaza and his colleagues found. Collectively, vultures in the Americas keep about 12 million metric tons of CO2 equivalent out of the atmosphere annually. Using estimates from the U.S. Environmental Protection Agency, that is akin to taking 2.6 million cars off the road each year. The situation outside of the Americas stands in stark contrast. "The decline in vulture populations in many regions of the world, such as Africa and Asia, has produced a concomitant loss of the ecosystem services vultures produce," Plaza says.

Specks of dust that a Japanese space probe retrieved from an asteroid about 186 million miles (300m kilometers) from Earth have revealed a surprising component: a drop of water. The discovery offers new support for the theory that life on Earth may have been seeded from outer space. The Guardian reports: The findings are in the latest research to be published from analysis of 5.4 grammes of stones and dust that the Hayabusa-2 probe gathered from the asteroid Ryugu. "This drop of water has great meaning," the lead scientist, Tomoki Nakamura of Tohoku University, told reporters before publication of the research in the journal Science on Friday. "Many researchers believe that water was brought [from outer space], but we actually discovered water in Ryugu, an asteroid near Earth, for the first time."

Hayabusa-2 was launched in 2014 on its mission to Ryugu, and returned to Earth's orbit two years ago to drop off a capsule containing the sample. The precious cargo has already yielded several insights, including organic material that showed some of the building blocks of life on Earth, amino acids, may have been formed in space. The team's latest discovery was a drop of fluid in the Ryugu sample "which was carbonated water containing salt and organic matter," Nakamura said. That bolsters the theory that asteroids such as Ryugu, or its larger parent asteroid, could have "provided water, which contains salt and organic matter" in collisions with Earth, he said. "We have discovered evidence that this may have been directly linked to, for example, the origin of the oceans or organic matter on Earth." "The fact that water was discovered in the sample itself is surprising," given its fragility and the chances of it being destroyed in outer space, said Kensei Kobayashi, an astrobiology expert and professor emeritus at Yokohama National University. "It does suggest that the asteroid contained water, in the form of fluid and not just ice, and organic matter may have been generated in that water."