The combination of extreme heat and drought that has scorched the Western United States and Canada over the past two weeks has killed hundreds of millions of mussels, clams and other marine animals, the New York Times reports. From a report: An estimated 1 billion small sea creatures died during the heat wave in the Salish Sea at the end of June, according to marine biologist Chris Harley, per the Washington Post. The sea creatures' deaths coincide with the heat wave that hit the Pacific Northwest last week, which led to more than a hundred human deaths. A study by an international team of climate researchers said the heat wave would have been "virtually impossible without human-caused climate change." Mussels attach themselves to rocks and other surfaces, but they generally can't survive temperatures over 100 degrees for extended periods of time, CNN reports.

Long-time Slashdot reader fahrbot-bot quotes LiveScience's exploration of the math: To start out 'small,' there are around 7 octillion, or 7x10^27 (7 followed by 27 zeros), atoms in an average human body, according to The Guardian. Given this vast sum of atoms in one person alone, you might think it would be impossible to determine how many atoms are in the entire universe. And you'd be right: Because we have no idea how large the entire universe really is, we can't find out how many atoms are within it.

However, it is possible to work out roughly how many atoms are in the observable universe — the part of the universe that we can see and study — using some cosmological assumptions and a bit of math.

[...]

Doing the math

To work out the number of atoms in the observable universe, we need to know its mass, which means we have to find out how many stars there are. There are around 10^11 to 10^12 galaxies in the observable universe, and each galaxy contains between 10^11 and 10^12 stars, according to the European Space Agency. This gives us somewhere between 10^22 and 10^24 stars. For the purposes of this calculation, we can say that there are 10^23 stars in the observable universe. Of course, this is just a best guess; galaxies can range in size and number of stars, but because we can't count them individually, this will have to do for now.

On average, a star weighs around 2.2x10^32 pounds (10^32 kilograms), according to Science ABC, which means that the mass of the universe is around 2.2x10^55 pounds (10^55 kilograms). Now that we know the mass, or amount of matter, we need to see how many atoms fit into it. On average, each gram of matter has around 10^24 protons, according to Fermilab, a national laboratory for particle physics in Illinois. That means it is the same as the number of hydrogen atoms, because each hydrogen atom has only one proton (hence why we made the earlier assumption about hydrogen atoms).

This gives us 10^82 atoms in the observable universe. To put that into context, that is 100,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 atoms.

This number is only a rough guess, based on a number of approximations and assumptions. But given our current understanding of the observable universe, it is unlikely to be too far off the mark.

From the Washington Post: When we are young, our skills tend to improve with age and experience. But once we are well into adulthood, it may start to feel as if it's all downhill. With every advancing year, we become slightly more forgetful, somewhat slower to respond, a little less energetic.

Yet there is at least one important exception: In the emotional realm, older people rule supreme.

For the past 20 years, Susan Turk Charles, a psychologist at the University of California at Irvine, has been monitoring the shifting moods, the sense of satisfaction, the moments of contemplation and the occasional outbursts of anger, sadness and despair of people of all ages — with a special interest in how we handle and experience emotions as we grow older. She and her colleagues have found that, on average, older people have fewer but more satisfying social contacts and report higher emotional well-being.... "I took a class from Laura Carstensen at Stanford, and she was the first to say that there was more development after age 18. She was finding that unlike physical fitness or cognition, where you may see slowing or declines, emotional regulation and experience are often as good, if not better, as we age... Some neuroscientists believe that because we're processing information a little slower with age, that makes us think before we act. We do see a decline with age in overall mass of the brain's frontal lobe, the part that is responsible for emotion regulation, complex reasoning and speed of processing. But researchers also find that older adults often exhibit greater prefrontal cortex activity than younger adults when processing emotions.

"A lot of work has found that older people have a positive bias, even without realizing they're doing this. Their default mode is 'Don't sweat the small stuff.' Older people more often let go of a situation they experience as negative, especially with friends and family. So it is picking their battles that we think older adults are better at..."

Q: Centenarians report overall high levels of emotional well-being. Some may wonder whether it might just be that people who have more positive attitudes, or encounter less adversity, live longer.

"It is true that people with satisfying relationships and positive emotions live longer. Researchers have looked at what could explain this, and they find that psychological well-being is related to lower levels of the stress hormone cortisol and better cardiovascular health."
Asked for suggestions, the researcher proposes an inner strategy that "takes you away from focusing on the future and reminds you that the present moment is the most important."

Long-time Slashdot reader schwit1 shares new from SciTechDaily: For the first time, University of Basel researchers have equipped an ultrathin semiconductor with superconducting contacts. These extremely thin materials with novel electronic and optical properties could pave the way for previously unimagined applications. Combined with superconductors, they are expected to give rise to new quantum phenomena and find use in quantum technology....

With a view to future applications in electronics and quantum technology, researchers are focusing on the development of new components that consist of a single layer (monolayer) of a semiconducting material. Some naturally occurring materials with semiconducting properties feature monolayers of this kind, stacked to form a three-dimensional crystal. In the laboratory, researchers can separate these layers — which are no thicker than a single molecule — and use them to build electronic components. These ultrathin semiconductors promise to deliver unique characteristics that are otherwise very difficult to control, such as the use of electric fields to influence the magnetic moments of the electrons. In addition, complex quantum mechanical phenomena take place in these semiconducting monolayers that may have applications in quantum technology...

A team of physicists, led by Dr. Andreas Baumgartner in the research group of Professor Christian Schönenberger at the Swiss Nanoscience Institute and the Department of Physics of the University of Basel, has now fitted a monolayer of the semiconductor molybdenum disulfide with superconducting contacts for the first time...

"In a superconductor, the electrons arrange themselves into pairs, like partners in a dance — with weird and wonderful consequences, such as the flow of the electrical current without a resistance," explains Baumgartner, the project manager of the study. "In the semiconductor molybdenum disulfide, on the other hand, the electrons perform a completely different dance, a strange solo routine that also incorporates their magnetic moments. Now we would like to find out which new and exotic dances the electrons agree upon if we combine these materials."
Mehdi Ramezani, lead author of the study, says that "In principle, the vertical contacts we've developed for the semiconductor layers can be applied to a large number of semiconductors."

UPDATE: Branson's done it. "In a live broadcast during the vehicle's descent, Branson called the trip, 'an experience of a lifetime,'" reports NBC News: Branson's flight took off Sunday morning at around 10:30 a.m. ET, although the launch time was delayed by around 90 minutes because of overnight weather conditions at Spaceport America...

Branson was joined on his flight by pilots Dave Mackay and Michael Masucci and three mission specialists, all of whom are employees of Virgin Galactic: Chief astronaut instructor Beth Moses, lead operations engineer Colin Bennett and government affairs vice president Sirisha Bandla.

Virgin Galactic is expected to conduct several additional test flights before beginning commercial operations with private customers next year. The company has said the suborbital joyrides will likely cost more than $250,000 each, but final pricing has not yet been announced...

"It's taken 17 years to get to this flight, and of course a lot of personal wealth has been poured into it, but it also shows that this takes tenacity," said Greg Autry, a space policy expert at Arizona State University.
Earlier in the day, Virgin Galactic's Twitter feed shared a nice clip of the astronauts arriving on the launch site.

CBS News streamed their own live coverage at the top of this web page (as well as in their CBSN app), but also reported on the other options: With typical Branson fanfare, Sunday's flight will be broadcast live across Virgin Galactic's social media platforms, featuring appearances by Stephen Colbert and retired Canadian space station astronaut Chris Hadfield, along with the performance of a new song by singer-songwriter Khalid. Even SpaceX founder Elon Musk plans to be watching. "Will see you there to wish you the best," he tweeted Saturday.
And what did Jeff Bezos have to say before Branson launched his history-making flight? "Wishing you and the whole team a successful and safe flight tomorrow. Best of luck!"

Saturday CBS News offered this description of Branson's hopes: Richard Branson, the globe-trotting media mogul and founder of Virgin Galactic, plans to rocket into space Sunday morning on a flight that would make him the first owner of a private space company to launch aboard one of his own spacecraft. If all goes well, he will beat rival Jeff Bezos of Blue Origin, who is set to launch on July 20. Branson, two company pilots and three Virgin Galactic crewmates are launching from Spaceport America, near Truth or Consequences, New Mexico, on what's expected to be at least an hour-long flight, reaching altitudes a little over 50 miles above the Earth.

In two hours, Richard Branson (and five other Virgin Galactic employees) will attempt a historic flight to the edge of outer space. Bloomberg points out it will be followed 9 days later by Jeff Bezos's rocket trip with Blue Origin on July 20.

"Yeah, there's a little bit of competition in the who's going first or when things are happening," Virgin President Mike Moses, a former space shuttle manager at NASA, told CBS News. "But it's really not a race. It's not a competition. I know that sounds maybe a little shallow or disingenuous, but it's not. "It's a small community. I know dozens of people who work at Blue Origin, I know dozens and dozens of people at SpaceX, and we all used to work together at NASA. And I wish every single one of them the best.... Because all of us together is what's going to get humans into space and our culture to recognize that space travel is the foundation for the future for everyone..."

"This has been a long journey for him," Mike Moses said of Branson. "He's like a kid in a candy store here in training this week. He's bouncing around, he's happy, excited. ... But that excitement is really infectious. And so the whole crew is feeling it."
CNN points out that Branson has "narrowly avoided being killed numerous times in his nearly 71 years," including dangerous stunts like bunjee jumping that left him bloody and injured, as well as accidents during long-distance balloon flights while attempting to set records.

Here's how Branson describes some of them in his second autobiography, "Finding My Virginity," which includes an appendix called "75 Close Shaves": 1972: Survived a fishing boat sinking on honeymoon with my first wife, Kristen, off Mexico. We decided to jump off the boat and swim for shore, while the others stayed put -- we were the only survivors.

1976: Flew a microlight aircraft by mistake. It was the first time I'd sat in it, I had no idea how to fly it and accidentally took off. I was pulling wires out desperately. I cut the engine and managed to crash-land into a field. My instructor died in an accident the next day...

1986: On my first time skydiving, there was one cord that opened the parachute and one that got rid of it. I pulled the wrong cord by mistake. I was falling through the air before an instructor managed to yank my spare ripcord...

1989: I decided to make an entrance to my wedding with Joan, dangling from a helicopter in an all-white suit. I dropped into the shallow end of the pool by mistake, smashed my legs, and spent the whole wedding hobbling.

Cho Jae-weon, an urban and environmental engineering professor at the Ulsan National Institute of Science and Technology (UNIST), has designed an eco-friendly toilet connected to a laboratory that uses excrement to produce biogas and manure. Reuters reports: The BeeVi toilet -- a portmanteau of the words bee and vision -- uses a vacuum pump to send feces into an underground tank, reducing water use. There, microorganisms break down the waste to methane, which becomes a source of energy for the building, powering a gas stove, hot-water boiler and solid oxide fuel cell. An average person defecates about 500g a day, which can be converted to 50 liters of methane gas, the environmental engineer said. This gas can generate 0.5kWh of electricity or be used to drive a car for about 1.2km (0.75 miles).

Cho has devised a virtual currency called Ggool, which means honey in Korean. Each person using the eco-friendly toilet earns 10 Ggool a day. Students can use the currency to buy goods on campus, from freshly brewed coffee to instant cup noodles, fruits and books. The students can pick up the products they want at a shop and scan a QR code to pay with Ggool.

An anonymous reader quotes a report from Stat News: Death rates are declining for more than half of the most common forms of cancer in the U.S., according to a sweeping annual analysis released Thursday. The new report -- released by the American Cancer Society, the National Cancer Institute, the Centers for Disease Control and Prevention, and other collaborators -- found that between 2014 and 2018, death rates dropped for 11 out of 19 of the most common cancers among men and 14 of the 20 most prevalent cancers among women.

Accelerating declines in lung cancer deaths may account for much of the overall progress seen in recent years, the authors of the report said. Over the past two decades, the death rate for lung cancer has declined even faster than the rate at which patients are diagnosed with the disease. And while part of the early success in preventing lung cancer can be attributed to the massive drop in smoking rates, the authors note the most recent downward trends seem to correspond with the approval of new treatments for non-small cell lung cancer that improved the likelihood of survival. Death rates from melanoma also saw an accelerated decline in the past decade, despite a growing number of diagnoses. Like in lung cancer, authors point to the introduction of novel treatments around the same time as the turnaround on the death rate. New targeted and immune checkpoint inhibitors were approved by the Food and Drug Administration in 2011, one year before major declines in death rates were seen in women and two years before they were seen in men.

While the report showed improved survival rates for many patients over recent years, others, such as prostate, colorectal, or female breast cancers, have seen progress stalled or stopped. Breast cancer continues to be one of the three deadliest cancers for women of all races, and the most frequently fatal cancer for Hispanic women. While the rates of death from breast cancer are declining, the pace of the decline has slowed over the past two decades, according to the report. And across the board, racial health disparities persist. Black women and white women are diagnosed with breast cancer at similar rates, but the mortality rate for Black women is 40% higher. Overall, cancer is more common among white individuals than Black individuals, but Black people die from cancer at higher rates. [The report] emphasized the importance of preventive measures for certain cancers, noting that while cancers related to smoking have continued to decrease, those related to excess body weight have increased. Early and consistent access to screenings has also been critical, as demonstrated by the apparent effect of adapted screening guidelines for colorectal cancer.

Yesterday, Moderna announced that the first set of volunteers in a clinical trial have received its mRNA-based seasonal flu vaccine. The Verge reports: Before the COVID-19 pandemic, mRNA vaccines were still largely experimental, even as they were heralded as the future of vaccine development. People who get an mRNA vaccine are injected with tiny snippets of genetic material from the target virus. Their cells use that genetic information to build bits of the virus, which the body's immune system learns to fight against. The high efficacy of the mRNA COVID-19 vaccines made by Moderna and Pfizer / BioNTech was a major endorsement for this type of vaccine. Now, pharmaceutical companies plan to use this technology to fight other types of infectious diseases, including flu.

The flu shots available each year in the United States are usually between 40 and 60 percent effective. The most common shots are made by growing the influenza virus in cells or chicken eggs, and then killing the virus so it's no longer dangerous. It takes a long time to grow the virus, so companies have to start making the shots around six months ahead of time, based on predictions around which strain of the flu will be circulating that year. Pharmaceutical companies hope that mRNA-based flu vaccines can be more effective than the traditional shots. Because they'd be faster to make, production wouldn't have to start so far in advance, and they could theoretically be more closely matched with the type of flu spreading each season.

To stay warm in frigid seas, the marine mammals rely on an unexpected use of the powerhouses of their cells. From a report: Sea otters run hot. It's not just a manner of speaking: Scientists have found that the furry mammals' metabolisms work at a rate three times what might normally be expected from a creature their size, burning swiftly through calories. They seem to be using much of that energy to generate heat, keeping themselves at a toasty 98.6 degrees Fahrenheit in the frigid ocean, where staying warm is a matter of life and death. But the details of their conversion of food and oxygen into vast reserves of heat have been obscure. Now researchers studying sea otters' muscles report that the feat involves using the mitochondria in their muscle cells in an unexpected way. Their study was published Thursday in the journal Science.

Unlike whales and polar bears, sea otters don't have a thick insulating layer of blubber, and their celebrated fur -- the thickest in the world, with up to 2.6 million hairs per square inch -- is not enough on its own to keep them alive in an ocean that can hover on the edge of freezing. Muscles generate heat as they contract, but scientists have known for some time there is another way that muscles can help animals keep warm, a cellular process with the delightful name of proton leak. Inside almost all animal cells, little pill-shaped organelles called mitochondria break down sugar molecules to extract energy. (Mitochondria are often called the powerhouses of the cell.) During the final stage of this process, protons pop through a membrane. In biology textbooks, the protons helpfully trickle through tiny spinning pores, driving them like water wheels to make adenosine triphosphate, a compound that serves as the molecular battery powering cellular processes.

The risk of pathogens spilling over from wildlife trade and farmed animals into humans should be key considerations in efforts to prevent the next pandemic, research suggests. From a report: Researchers have been assessing the risks of the different ways that disease-causing organisms jump from animals to humans in an effort to characterise and address the risk of the next pandemic. In a study published in the journal Biological Reviews, University of Cambridge scientists found that while the risk of another pandemic cannot be eliminated, systemic changes in the way we interact with animals, in general, could substantially minimise the probability.

The risks are not just linked to exotic wild animals, they caution. "There's a natural tendency, particularly in the western world, to imagine that this has nothing to do with us. It's something remote and exotic ⦠something that someone else has been doing," said the study's lead author Dr Silviu Petrovan, a veterinarian and wildlife expert at Cambridge. "I suppose what most people have in their minds is not the venison that they buy in Waitrose -- which, of course, is wildlife -- but rather something altogether more exotic."

Indian scientists have discovered a new plant species in Antarctica. From a report: Polar biologists stumbled upon a species of moss during an expedition to the ice-covered continent in 2017. Identification is laborious, and it took the scientists five years to confirm that the species had been discovered for the first time. The peer-reviewed paper describing this discovery has been accepted in the leading international journal, Journal of Asia-Pacific Biodiversity. The biologists, based in the Central University of Punjab, have named the specie Bryum Bharatiensis. Bharati is the Hindu goddess of learning and the name of one of India's Antarctic research stations. Prof Felix Bast, a biologist who was part of the six-month-long expedition to the continent - the 36th by Indian scientists - discovered the dark green specie at Larsemann Hills, overlooking the Southern Ocean, in January 2017. This is located near Bharati, one of the remotest research stations in the world.

An anonymous reader writes: One in five Americans uses a Fitbit, Apple Watch or other wearable fitness tracker. And over the past year, several studies have suggested that the devices -- which can continually collect data on heart rates, body temperature, physical activity and more -- could help detect early signs of Covid-19 symptoms. Now, research suggests that these wearables can also help track patients' recovery from the disease, providing insight into its long-term effects. In a paper published on Wednesday in the journal JAMA Network Open, researchers studying Fitbit data reported that people who tested positive for Covid-19 displayed behavioral and physiological changes, including an elevated heart rate, that could last for weeks or months. These symptoms lasted longer in people with Covid than in those with other respiratory illnesses, the scientists found.

The new study focuses on a subset of 875 Fitbit-wearing participants who reported a fever, cough, body aches or other symptoms of a respiratory illness and were tested for Covid-19. Of those, 234 people tested positive for the disease. The rest were presumed to have other kinds of infections. Participants in both groups slept more and walked less after they got sick, and their resting heart rates rose. But these changes were more pronounced in people with Covid-19. "There was a much larger change in resting heart rate for individuals who had Covid compared to other viral infections," said Jennifer Radin, an epidemiologist at Scripps who leads the DETECT trial. "We also have a much more drastic change in steps and sleep." The scientists also found that about nine days after participants with Covid first began reporting symptoms, their heart rates dropped. After this dip, which was not observed in those with other illnesses, their heart rates rose again and remained elevated for months. It took 79 days, on average, for their resting heart rates to return to normal, compared with just four days for those in the non-Covid group.

This prolonged heart rate elevation may be a sign that Covid-19 disrupts the autonomic nervous system, which regulates basic physiological processes. The heart palpitations and dizziness reported by many people who are recovering from Covid may be symptoms of this disruption. Sleep and physical activity levels also returned to baseline more slowly in those with Covid-19 compared to those with other ailments, Dr. Radin and her colleagues found. The researchers identified a small subset of people with Covid whose heart rates remained more than five beats per minute above normal one to two months after infection. Nearly 14 percent of those with the disease fell into this category, and their heart rates did not return to normal for more than 133 days, on average. These participants were also significantly more likely to report having had a cough, shortness of breath and body aches during the acute phase of their illness than did other Covid patients.

The UK's most powerful supercomputer, which its creators hope will make the process of preventing, diagnosing and treating disease better, faster and cheaper, is operational. The Guardian reports: Christened Cambridge-1, the supercomputer represents a $100m investment by US-based computing company Nvidia. The idea capitalizes on artificial intelligence (AI) -- which combines big data with computer science to facilitate problem-solving -- in healthcare. [...] Cambridge-1's first projects will be with AstraZeneca, GSK, Guy's and St Thomas' NHS foundation trust, King's College London and Oxford Nanopore. They will seek to develop a deeper understanding of diseases such as dementia, design new drugs, and improve the accuracy of finding disease-causing variations in human genomes.

A key way the supercomputer can help, said Dr Kim Branson, global head of artificial intelligence and machine learning at GSK, is in patient care. In the field of immuno-oncology, for instance, existing medicines harness the patient's own immune system to fight cancer. But it isn't always apparent which patients will gain the most benefit from these drugs -- some of that information is hidden in the imaging of the tumors and in numerical clues found in blood. Cambridge-1 can be key to helping fuse these different datasets, and building large models to help determine the best course of treatment for patients, Branson said.

An anonymous reader quotes a report from Phys.Org: Scientists at KAIST have fabricated a laser system that generates highly interactive quantum particles at room temperature. Their findings, published in the journal Nature Photonics, could lead to a single microcavity laser system that requires lower threshold energy as its energy loss increases. The system, developed by KAIST physicist Yong-Hoon Cho and colleagues, involves shining light through a single hexagonal-shaped microcavity treated with a loss-modulated silicon nitride substrate. The system design leads to the generation of a polariton laser at room temperature, which is exciting because this usually requires cryogenic temperatures.

The researchers found another unique and counter-intuitive feature of this design. Normally, energy is lost during laser operation. But in this system, as energy loss increased, the amount of energy needed to induce lasing decreased. Exploiting this phenomenon could lead to the development of high efficiency, low threshold lasers for future quantum optical devices. [...] The key is the design and materials. The hexagonal microcavity divides light particles into two different modes: one that passes through the upward-facing triangle of the hexagon and another that passes through its downward-facing triangle. Both modes of light particles have the same energy and path but don't interact with each other. However, the light particles do interact with other particles called excitons, provided by the hexagonal microcavity, which is made of semiconductors. This interaction leads to the generation of new quantum particles called polaritons that then interact with each other to generate the polariton laser. By controlling the degree of loss between the microcavity and the semiconductor substrate, an intriguing phenomenon arises, with the threshold energy becoming smaller as energy loss increases.

NASA's next big space telescope just took a big step forward toward its planned launch this fall. From a report: The $9.8 billion James Webb Space Telescope mission has passed a key launch review, keeping it on track to lift off atop an Ariane 5 rocket before the end of the year, European Space Agency (ESA) officials announced last week. "This major milestone, carried out with Arianespace, the Webb launch service provider, confirms that Ariane 5, the Webb spacecraft and the flight plan are set for launch," ESA officials wrote in a July 1 update. "It also specifically provides the final confirmation that all aspects of the launch vehicle and spacecraft are fully compatible."

While Webb is primarily a NASA mission, ESA and the Canadian Space Agency (CSA) are important partners. The CSA is providing the telescope's guidance sensor and one of its scientific instruments. ESA is contributing some science gear to the mission as well and is also providing launch services, procuring the Ariane 5 heavy lifter to get Webb off the ground. The launch will take place from Europe's Spaceport in Kourou, French Guiana. Mission teams are working toward a launch readiness date of Oct. 31, but liftoff is not expected to actually take place on Halloween. "The precise launch date following 31 October depends on the spaceport's launch schedule and will be finalized closer to the launch readiness date," ESA officials wrote in the same statement.

The University of Oxford this week started vaccinations of a novel HIV vaccine candidate as part of a Phase I clinical trial in the UK. From a report: The goal of the trial, known as HIV-CORE 0052, is to evaluate the safety, tolerability, and immunogenicity of the HIVconsvX vaccine -- a mosaic vaccine targeting a broad range of HIV-1 variants, making it potentially applicable for HIV strains in any geographical region. Thirteen healthy, HIV-negative adults, aged 18-65 and who are considered not to be at high risk of infection, will initially receive one dose of the vaccine followed by a further booster dose at four weeks. The trial is part of the European Aids Vaccine Initiative (EAVI2020), an internationally collaborative research project funded by the European Commission under Horizon 2020 health programme for research and innovation.

Professor Tomas Hanke, Professor of Vaccine Immunology at the Jenner Institute, University of Oxford, and lead researcher on the trial, said: 'An effective HIV vaccine has been elusive for 40 years. This trial is the first in a series of evaluations of this novel vaccine strategy in both HIV-negative individuals for prevention and in people living with HIV for cure.' While most HIV vaccine candidates work by inducing antibodies generated by B-cells, HIVconsvX induces the immune system's potent, pathogen obliterating T cells, targeting them to highly conserved and therefore vulnerable regions of HIV -- an "Achilles heel" common to most HIV variants.

An anonymous reader shares a report: As we carefully map the stars of our Milky Way, we're able to identify features that tell us of its history. These include local details, such as the stars that have passed through an area from which something would be able to detect Earth. And it includes far larger structures, like the trails of stars left behind by smaller galaxies that have merged with our own. But one feature we've discovered has been a bit confusing: trails of stars that are too small and thin to have come from a galaxy collision. There are dozens of them that we've not identified a source for. Their size suggests they came from a globular cluster, but there's no obvious mechanism for these clusters to eject stars at a rate sufficient to generate this sort of stream. Now, a team of researchers has suggested a not-so-obvious mechanism: Over time, clusters may become dominated by black holes that eject all the stars.

Globular clusters are dense groups of stars that orbit the Milky Way together. They're held in association by their mutual gravity. Complex interactions will inevitably eject some of the stars, but not at an appreciable rate, which makes the clusters extremely long-lived. The researchers started their work, however, by looking at an unusual globular cluster called Palomar 5. It has both extended tails of lost stars, and its total mass is relatively small, making it diffuse compared to other clusters we've studied. The lower density makes it easier for Palomar 5 to lose stars, but it could also have been caused by past star loss, creating a bit of a chicken-and-egg problem. So, the researchers decided to model globular cluster evolution and try to find a model that could produce something that looks like Palomar 5. The researchers created a model that takes a cluster of stars and models their gravitational interactions with each other and the Milky Way as they orbit the galactic center. Thanks to some help from a cluster of GPUs and the right software, they were able to run these simulations for billions of years. By changing the parameters, they could find which factors were associated with clusters that ended up looking like Palomar 5.

A team of Korean scientists may have found a way to desalinate seawater in minutes. An anonymous reader quotes a report from Interesting Engineering: When using membranes to filter seawater, the membrane must remain dry for long periods of time. If the membrane becomes wet, the filtration process becomes ineffective and allows large amounts of salt to pass through the membrane. For long term operations, progressive membrane wetting has been observed regularly, which be resolved by changing the membrane. Researcher Yunchul Woo and his team at the Korea Institute of Civil Engineering and Building Technology (KICT) have now developed a membrane that is less susceptible to wetting and is stable in the long term.

The membrane is made of nanofibers that have been fabricated into a three-dimensional hierarchical structure, This was achieved by using a type of nanotechnology called electrospinning. Using this technology, the researchers were able to fabricate a membrane that is highly hydrophobic -- i.e. water repellent. The hydrophobic nature of the membrane is helpful because it is designed to not allow water molecules to pass. Instead, a temperature difference is applied on the two sides of the membrane that causes water from one end to evaporate into water vapor. The membrane allows water vapor to pass, which then condenses onto the cooler side. Called, membrane distillation, this is a commonly used method of desalination using membranes. Since the salt particles are not converted to the gaseous state, they are left out on one side of the membrane, giving highly purified water on the other side. The Korean researchers also used silica aerogel in their membrane fabrication process which further enhanced the flow of water vapor through the membrane, providing quicker access to desalinated water. The team tested their technology for continuous operation for 30 days and found that the membrane continued to filter out 99.9 percent salt without any wetting issues. The study has been published in the Journal of Membrane Science.

NASA announced on Monday that Ingenuity's ninth flight was a success, as it undertook a "high-speed flight across unfriendly terrain." The Hill reports: Ingenuity flew for 166.4 seconds at a pace of 5 meters per second over a terrain of high slopes -- all new records for the helicopter. In preparation for the flight, NASA said, "First, we believe Ingenuity is ready for the challenge, based on the resilience and robustness demonstrated in our flights so far. Second, this high-risk, high-reward attempt fits perfectly within the goals of our current operational demonstration phase. A successful flight would be a powerful demonstration of the capability that an aerial vehicle (and only an aerial vehicle) can bring to bear in the context of Mars exploration -- traveling quickly across otherwise untraversable terrain while scouting for interesting science targets."