Science

Peacock Feathers Can Be Lasers (science.org) 33

sciencehabit shares a report from Science.org: Peacocks have a secret hidden in their brightly colored tail feathers: tiny reflective structures that can amplify light into a laser beam. After dyeing the feathers and energizing them with an external light source, researchers discovered they emitted narrow beams of yellow-green laser light. They say the study, published this month in Scientific Reports, offers the first example of a laser cavity in the animal kingdom. [...]

Scientists have long known that peacock feathers also exhibit "structural color" -- nature's pigment-free way to create dazzling hues. Ordered microstructures within the feathers reflect light at specific frequencies, leading to their vivid blues and greens and iridescence. But Florida Polytechnic University physicist Nathan Dawson and his colleagues wanted to go a step further and see whether those microstructures could also function as a laser cavity. After staining the feathers with a common dye and pumping them with soft pulses of light, they used laboratory instruments to detect beams of yellow-green laser light that were too faint to see with the naked eye. They emerged from the feathers' eyespots, at two distinct wavelengths. Surprisingly, differently colored parts of the eyespots emitted the same wavelengths of laser light, even though each region would presumably vary in its microstructure.

Just because peacock feathers emit laser light doesn't mean the birds are somehow using this emission. But there are still ramifications, Dawson says. He suggests that looking for laser light in biomaterials could help identify arrays of regular microstructures within them. In medicine, for example, certain foreign objects -- viruses with distinct geometric shapes, perhaps -- could be classified and identified based on their ability to be lasers, he says. The work also demonstrates how biological materials could one day yield lasers that could be put safely into the human body to emit light for biosensing, medical imaging, and therapeutics. "I always like to think that for many technological achievements that benefit humans," Dawson says, "some organism somewhere has already developed it through some evolutionary process."

NASA

India Launches NASA-ISRO Satellite To Track Climate Threats From Space (reuters.com) 21

India launched the $1.5 billion NISAR radar imaging satellite on Wednesday from the Satish Dhawan Space Centre, marking the first joint mission between NASA and the Indian Space Research Organisation. The satellite uses dual radar frequencies -- NASA's L-band and ISRO's S-band -- to detect Earth surface changes as small as one centimeter from its 747-kilometer orbit.

NISAR will map the entire planet every 12 days using a 240-kilometer-wide radar swath, providing data for climate monitoring and disaster response that will be freely available to users worldwide.
Science

Famous Double-Slit Experiment Holds Up When Stripped To Its Quantum Essentials (mit.edu) 23

Longtime Slashdot reader ndsurvivor shares a report from MIT: MIT physicists have performed an idealized version of one of the most famous experiments in quantum physics. Their findings demonstrate, with atomic-level precision, the dual yet evasive nature of light. They also happen to confirm that Albert Einstein was wrong about this particular quantum scenario. The experiment in question is the double-slit experiment, which was first performed in 1801 by the British scholar Thomas Young to show how light behaves as a wave. Today, with the formulation of quantum mechanics, the double-slit experiment is now known for its surprisingly simple demonstration of a head-scratching reality: that light exists as both a particle and a wave. Stranger still, this duality cannot be simultaneously observed. Seeing light in the form of particles instantly obscures its wave-like nature, and vice versa.

[...] Now, MIT physicists have performed the most "idealized" version of the double-slit experiment to date. Their version strips down the experiment to its quantum essentials. They used individual atoms as slits, and used weak beams of light so that each atom scattered at most one photon. By preparing the atoms in different quantum states, they were able to modify what information the atoms obtained about the path of the photons. The researchers thus confirmed the predictions of quantum theory: The more information was obtained about the path (i.e. the particle nature) of light, the lower the visibility of the interference pattern was. They demonstrated what Einstein got wrong. Whenever an atom is "rustled" by a passing photon, the wave interference is diminished. "Einstein and Bohr would have never thought that this is possible, to perform such an experiment with single atoms and single photons," says Wolfgang Ketterle, the John D. MacArthur Professor of Physics and leader of the MIT team. "What we have done is an idealized Gedanken experiment." Their results appear in the journal Physical Review Letters.

Medicine

A Pill for Sleep Apnea Could Be on the Horizon 61

Promising Phase 3 trial results from Apnimed suggest a potential game-changing oral pill for sleep apnea could offer a simpler, more tolerable alternative for keeping airways open during sleep. The New York Times reports: For decades, the primary treatment for sleep apnea has been continuous positive airway pressure (or CPAP). Before bed, those with the condition put on a face mask that is connected to a CPAP machine, which keeps the airway open by forcing air into it. The machines are effective, but many find them so noisy, cumbersome or uncomfortable that they end up abandoning them. Now, a more appealing option may be on the way, according to a news release from Apnimed, a pharmaceutical company focused on treating sleep apnea. On Wednesday, the company announced a second round of positive Phase 3 clinical trial results for a first-of-its-kind oral pill that can be taken just before bedtime to help keep a person's airway open.

The full results have not yet been released, or published in a peer-reviewed journal. But the findings build on past, similarly positive conclusions from trials and studies. Sleep experts say that what they're seeing in reports so far makes them think the pill could be a game changer. Dr. Phyllis Zee, a sleep doctor and researcher at Northwestern Medicine who was not involved with the trial, said that if approved, the drug could transform the lives of many. That includes not only those who can't tolerate CPAP machines, but also those who can't -- or prefer not to -- use other interventions, such as other types of oral devices or weight loss medications. (Excess weight is a risk factor for sleep apnea.)
Space

Distorted Sound of the Early Universe Suggests We Are Living In a Giant Void (phys.org) 49

A new study analyzing distorted sound waves from the early universe suggests we may live in a massive cosmic void "with roughly 20% lower than the average density of matter," writes Indranil Banik in an article for The Conversation. "Not every physicist is convinced that this is the case. But our recent paper analyzing distorted sounds from the early universe, published in the Monthly Notices of the Royal Astronomical Society, strongly backs up the idea." Slashdot reader alternative_right shares an excerpt from the report: My colleagues and I previously argued that the Hubble tension might be due to our location within a large void. That's because the sparse amount of matter in the void would be gravitationally attracted to the more dense matter outside it, continuously flowing out of the void. In previous research, we showed that this flow would make it look like the local universe is expanding about 10% faster than expected. That would solve the Hubble tension. But we wanted more evidence. And we know a local void would slightly distort the relation between the BAO angular scale and the redshift due to the faster moving matter in the void and its gravitational effect on light from outside.

So in our new paper, Vasileios Kalaitzidis and I set out to test the predictions of the void model using BAO measurements collected over the last 20 years. We compared our results to models without a void under the same background expansion history. In the void model, the BAO ruler should look larger on the sky at any given redshift. And this excess should become even larger at low redshift (close distance), in line with the Hubble tension. The observations confirm this prediction. Our results suggest that a universe with a local void is about one hundred million times more likely than a cosmos without one, when using BAO measurements and assuming the universe expanded according to the standard model of cosmology informed by the CMB.

Our research shows that the ACDM model without any local void is in "3.8 sigma tension" with the BAO observations. This means the likelihood of a universe without a void fitting these data is equivalent to a fair coin landing heads 13 times in a row. By contrast, the chance of the BAO data looking the way they do in void models is equivalent to a fair coin landing heads just twice in a row. In short, these models fit the data quite well. In the future, it will be crucial to obtain more accurate BAO measurements at low redshift, where the BAO standard ruler looks larger on the sky -- even more so if we are in a void. The average expansion rate so far follows directly from the age of the universe, which we can estimate from the ages of old stars in the Milky Way. A local void would not affect the age of the universe, but some proposals do affect it. These and other probes will shed more light on the Hubble crisis in cosmology.

Science

Ageing Accelerates at Around Age 50 - Some Organs Faster Than Others (nature.com) 57

A new analysis of protein changes across human tissues has identified an aging acceleration point around age 50, with blood vessels showing the most dramatic deterioration. Researchers examined tissue samples from eight body systems in 76 people of Chinese ancestry aged 14 to 68 who died from accidental brain injury, finding age-related increases in 48 disease-associated proteins.

Between ages 45 and 55, the most significant shift occurred in the aorta, the body's main artery carrying oxygenated blood from the heart. The team identified one aortic protein that triggers accelerated aging signs when administered to mice. Early aging changes appeared around age 30 in the adrenal gland, which produces various hormones. The study, published in Cell, adds to mounting evidence that aging occurs in waves rather than following a steady progression.
Space

Astronomers Use Black Holes to Pinpoint Earth's Location. But are Phones and Wifi Blocking the View? (space.com) 45

Measuring earth's position (or "geodesy") requires using telescopes that track radiation from distant black holes. Their signals "pass cleanly through the atmosphere and we can receive them during day and night and in all weather conditions," writes a senior scientist at the University of Tasmania.

But there's a problem... Radio waves are also used for communication on Earth — including things such as wifi and mobile phones... [A] few narrow lanes are reserved for radio astronomy. However, in previous decades the radio highway had relatively little traffic. Scientists commonly strayed from the radio astronomy lanes to receive the black hole signals. To reach the very high precision needed for modern technology, geodesy today relies on more than just the lanes exclusively reserved for astronomy.

In recent years, human-made electromagnetic pollution has vastly increased. When wifi and mobile phone services emerged, scientists reacted by moving to higher frequencies. However, they are running out of lanes. Six generations of mobile phone services (each occupying a new lane) are crowding the spectrum... Today, the multitude of signals are often too strong for geodetic observatories to see through them to the very weak signals emitted by black holes. This puts many satellite services at risk.

To keep working into the future — to maintain the services on which we all depend — geodesy needs some more lanes on the radio highway. When the spectrum is divided up via international treaties at world radio conferences, geodesists need a seat at the table. Other potential fixes might include radio quiet zones around our essential radio telescopes. Work is also underway with satellite providers to avoid pointing radio emissions directly at radio telescopes. Any solution has to be global. For our geodetic measurements, we link radio telescopes together from all over the world, allowing us to mimic a telescope the size of Earth. The radio spectrum is primarily regulated by each nation individually, making this a huge challenge.

But perhaps the first step is increasing awareness. If we want satellite navigation to work, our supermarkets to be stocked and our online money transfers arriving safely, we need to make sure we have a clear view of those black holes in distant galaxies — and that means clearing up the radio highway.

China

'Serious Delays' Hit Satellite Mega-Constellations of China's Starlink Rivals (scmp.com) 29

"A Chinese mega-constellation of communications satellites is facing serious delays," reports the South China Morning Post, "that could jeopardise its ambitions to compete with SpaceX's Starlink for valuable orbital resources." Only 90 satellites have been launched into low Earth orbit for the Qianfan broadband network — also known as the Thousand Sails Constellation or G60 Starlink — well short of the project's goal of 648 by the end of this year... Shanghai Yuanxin Satellite Technology, the company leading the project, plans to deploy more than 15,000 satellites by 2030 to deliver direct-to-phone internet services worldwide. To stay on track, Yuanxin — which is backed by the Shanghai municipal government — would have to launch more than 30 satellites a month to achieve its milestones of 648 by the end of 2025 for regional coverage and 1,296 two years later for global connectivity.
The New York Times reports that "the other megaconstellation, Guowang, is even farther behind. Despite plans to launch about 13,000 satellites within the next decade, it has 34 in orbit." A constellation has to launch half of its satellites within five years of successfully applying for its frequencies, and complete the full deployment within seven years, according to rules set by the International Telecommunication Union, a United Nations agency that allocates frequencies. The Chinese megaconstellations are behind on these goals. Companies that fail to hit their targets could be required to reduce the size of their megaconstellations.
Meanwhile SpaceX "has about 8,000 Starlink satellites in orbit and is expanding its lead every month," the Times writes, citing data from the U.S. Space Force and the nonprofit space-data group CelesTrak. (The Times has even created an animation showing Starlink's 8,000 satellites in orbit.) Researchers for the People's Liberation Army predict that the network will become "deeply embedded in the U.S. military combat system." They envision a time when Starlink satellites connect U.S. military bases and serve as an early missile-warning and interception network....

One of the major reasons for China's delay is the lack of a reliable, reusable launcher. Chinese companies still launch satellites using single-use rockets. After the satellites are deployed, rocket parts tumble back to Earth or become space debris... Six years after [SpaceX's] Falcon 9 began launching Starlink satellites, Chinese firms still have no answer to it... The government has tested nearly 20 rocket launchers in the "Long March" series.

Moon

Asteroid 2024 YR4 Spared The Earth. What Happens if It Hits the Moon Instead in 2032? (cnn.com) 22

Remember asteroid 2024 YR4 (which at one point had a 1 in 32 chance of hitting Earth, before ending up at "impact probability zero")? CNN reports that asteroid is now "zooming beyond the reach of telescopes on its orbit around the sun."

"But as scientists wait for it to reappear, its revised trajectory is now drawing attention to another possible target: the moon." The latest observations of the asteroid in early June, before YR4 disappeared from view, have improved astronomers' knowledge of where it will be in seven years by almost 20%, according to NASA. That data shows that even with Earth avoiding direct impact, YR4 could still pose a threat in late 2032 by slamming into the moon. ["The asteroid's probability of impacting the Moon has slightly increased from 3.8% to 4.3%," writes NASA, and "it would not alter the Moon's orbit."]
CNN calls the probabiliy "small but decent enough odds for scientists to consider how such a scenario might play out." The collision could create a bright flash that would be visible with the naked eye for several seconds, according to Wiegert, lead author of a recent paper submitted to the American Astronomical Society journals analyzing the potential lunar impact. The collision could create an impact crater on the moon estimated at 1 kilometer wide (0.6 miles wide), Wiegert said... It would be the largest impact on the moon in 5,000 years and could release up to 100 million kilograms (220 million pounds) of lunar rocks and dust, according to the modeling in Wiegert's study... Particles the size of large sand grains, ranging from 0.1 to 10 millimeters in size, of lunar material could reach Earth between a few days and a few months after the asteroid strike because they'll be traveling incredibly fast, creating an intense, eye-catching meteor shower, Wiegert said.

"There's absolutely no danger to anyone on the surface," Wiegert said. "We're not expecting large boulders or anything larger than maybe a sugar cube, and our atmosphere will protect us very nicely from that. But they're traveling faster than a speeding bullet, so if they were to hit a satellite, that could cause some damage...." Hundreds to thousands of impacts from millimeter-size debris could affect Earth's satellite fleet, meaning satellites could experience up to 10 years' equivalent of meteor debris exposure in a few days, Wiegert said... While a temporary loss of communication and navigation from satellites would create widespread difficulties on Earth, Wiegert said he believes the potential impact is something for satellite operators, rather than the public, to worry about.

"Any missions in low-Earth orbit could also be in the pathway of the debris, though the International Space Station is scheduled to be deorbited before any potential impact," reports CNN.

And they add that Wiegert also believes even small pieces of debris (tens of centimeters in size) "could present a hazard for any astronauts who may be present on the moon, or any structures they have built for research and habitation... The moon has no atmosphere, so the debris from the event could be widespread on the lunar surface, he added."
Science

Controversial 'Arsenic Life' Paper Retracted After 15 Years (nature.com) 21

"So far, all lifeforms on Earth have a phosphorous-based chemistry, particularly as the backbone of DNA," writes longtime Slashdot reader bshell. "In 2010, a paper was published in Science claiming that arsenic-based bacteria were living in a California lake (in place of phosphorous). That paper was finally retracted by the journal Science the other day." From a report: : Some scientists are celebrating the move, but the paper's authors disagree with it -- saying that they stand by their data and that a retraction is not merited. In Science's retraction statement, editor-in-chief Holden Thorp says that the journal did not retract the paper when critics published take-downs of the work because, back then, it mostly reserved retractions for cases of misconduct, and "there was no deliberate fraud or misconduct on the part of the authors" of the arsenic-life paper. But since then, Science's criteria for retracting papers have expanded, he writes, and "if the editors determine that a paper's reported experiments do not support its key conclusions," as is the case for this paper, a retraction is now appropriate.

"It's good that it's done," says microbiologist Rosie Redfield, who was a prominent critic of the study after its publication in 2010 and who is now retired from the University of British Columbia in Vancouver, Canada. "Pretty much everybody knows that the work was mistaken, but it's still important to prevent newcomers to the literature from being confused." By contrast, one of the paper's authors, Ariel Anbar, a geochemist at Arizona State University in Tempe, says that there are no mistakes in the paper's data. He says that the data could be interpreted in a number of ways, but "you don't retract because of a dispute about data interpretation." If that's the standard you were to apply, he says, "you'd have to retract half the literature."

Earth

Study Finds 'Pressure Point' In the Gulf Could Drive Hurricane Strength (phys.org) 33

alternative_right shares a report from Phys.org: Driven by high temperatures in the Gulf, Hurricane Ian rapidly intensified from a Category 3 to Category 5 before making landfall in Southwest Florida on September 28, 2022. The deadly storm caught many by surprise and became the costliest hurricane in state history. Now, researchers from the University of South Florida say they've identified what may have caused Ian to develop so quickly. A strong ocean current called the Loop Current failed to circulate water in the shallow region of the Gulf. As a result, subsurface waters along the West Coast of Florida remained unusually warm during the peak of hurricane season. [...]

The researchers found that if the Loop Current reaches an area near the Dry Tortugas, which they call the "pressure point," it can flush warm waters from the West Florida Shelf and replace it with cold water from deeper regions of the Gulf. This pressure point is where the shallow contours of the seafloor converge, forcing cold water to the surface in a process known as upwelling. In the months leading up to Hurricane Ian, the Loop Current did not reach the pressure point, leaving the waters on the shelf unmixed, which caused both the surface and subsurface waters on the West Florida Shelf to remain warm throughout summer.
The findings have been published in Geophysical Research Letters.
Science

Clean Cyclists Now Outperform Doped Champions of Tour de France's Past (theatlantic.com) 57

Current Tour de France competitors are faster than the sport's notorious doping-era champions, according to an analysis. Tadej Pogacar produced approximately 7 watts per kilogram for nearly 40 minutes during a crucial mountain stage in last year's Tour de France. Jonas Vingegaard, generated more than 7 watts per kilogram for nearly 15 minutes during a failed attack attempt. Lance Armstrong, at his blood-doped peak two decades ago, averaged an estimated 6 watts per kilogram and took nearly six minutes longer than Pogacar on the same Pyrenees climb in 2004.

The performance gains stem from multiple technological advances. Every rider now uses power meters that provide real-time performance data. Nutrition has shifted from minimal fueling to constant calorie replenishment with precisely measured food intake. Equipment undergoes extensive wind tunnel testing to reduce drag coefficients. Teams use apps like VeloViewer to preview race courses and weather forecasting to optimize wheel selection. "The bias is in favor of clean athletes: that you can be clean and win," said Travis Tygart, chief executive of the U.S. Anti-Doping Agency.
Science

Air Pollution Raises Risk of Dementia, Say Cambridge Scientists (theguardian.com) 34

Exposure to certain forms of air pollution is linked to an increased risk of developing dementia, according to the most comprehensive study of its kind. From a report: The illness is estimated to affect about 57 million people worldwide, with the number expected to increase to at least 150m cases by 2050. The report, which was produced by researchers at the Medical Research Council's epidemiology unit at the University of Cambridge involved a systematic review of 51 studies.

It drew on data from more than 29 million participants who had been exposed to air pollutants for at least a year. Although air pollution has already been identified as a risk factor for dementia, the research, which is the most comprehensive study of its kind to date, found there to be a positive and statistically-significant association between three types of air pollutant and dementia.

Space

Largest-Ever Supernova Catalog Provides Further Evidence Dark Energy Is Weakening (space.com) 18

Scientists using the largest-ever catalog of Type 1a supernovas -- cosmic explosions from white dwarf "vampire stars" -- have uncovered further evidence that dark energy may not be constant. While the findings are still preliminary, they suggest the mysterious force driving the universe's expansion could be weakening, which "would have ramifications for our understanding of how the cosmos will end," reports Space.com. From the report: By comparing Type 1a supernovas at different distances and seeing how their light has been redshifted by the expansion of the universe, the value for the rate of expansion of the universe (the Hubble constant) can be obtained. Then, that can be used to understand the impact of dark energy on the cosmos at different times. This story is fitting because it was the study of 50 Type 1a supernovas that first tipped astronomers off to the existence of dark energy in the first place back in 1998. Since then, astronomers have observed a further 2,000 Type 1a supernovas with different telescopes. This new project corrects any differences between those observations caused by different astronomical instruments, such as how the filters of telescopes drift over time, to curate the largest standardized Type 1a supernova dataset ever. It's named Union3.

Union3 contains 2,087 supernovas from 24 different datasets spanning 7 billion years of cosmic time. It builds upon the 557 supernovas catalogued in an original dataset called Union2. Analysis of Union3 does indeed seem to corroborate the results of DESI -- that dark energy is weakening over time -- but the results aren't yet conclusive. What is impressive about Union3, however, is that it presents two separate routes of investigation that both point toward non-constant dark energy. "I don't think anyone is jumping up and down getting overly excited yet, but that's because we scientists are suppressing any premature elation since we know that this could go away once we get even better data," Saul Perlmutter, study team member and a researcher at Berkeley Lab, said in a statement. "On the other hand, people are certainly sitting up in their chairs now that two separate techniques are showing moderate disagreement with the simple Lambda CDM model."

And when it comes to dark energy in general, Perlmutter says the scientific community will pay attention. After all, he shared the 2011 Nobel Prize in Physics for discovering this strange force. "It's exciting that we're finally starting to reach levels of precision where things become interesting and you can begin to differentiate between the different theories of dark energy," Perlmutter said.

Medicine

Scientists Are Developing Artificial Blood That Could Save Lives In Emergencies (npr.org) 42

Scientists at the University of Maryland are developing ErythroMer, a freeze-dried artificial blood substitute made from hemoglobin encased in fat bubbles, designed to be shelf-stable for years and reconstituted with water in emergencies. With promising animal trial results and significant funding from the Department of Defense, the team aims to begin human testing within two years. NPR reports: "The No. 1 cause of preventable death on the battlefield is hemorrhage still today," says Col. Jeremy Pamplin, the project manager at the Defense Advanced Research Projects Agency. "That's a real problem for the military and for the civilian world." [Dr. Allan Doctor, a scientist at the University of Maryland working to develop the artificial blood substitute] is optimistic his team may be on the brink of solving that problem with ... ErythroMer. Doctor co-founded KaloCyte to develop the blood and serves on the board and as the firm's chief scientific officer.

"We've been able to successfully recapitulate all the functions of blood that are important for a resuscitation in a system that can be stored for years at ambient temperature and be used at the scene of an accident," he says. [...] Doctor's team has tested their artificial blood on hundreds of rabbits and so far it looks safe and effective. "It would change the way that we could take care of people who are bleeding outside of hospitals," Doctor says. "It'd be transformative." [...]

While the results so far seem like cause for optimism, Doctor says he still needs to prove to the Food and Drug Administration that his artificial blood would be safe and effective for people. But he hopes to start testing it in humans within two years. A Japanese team is already testing a similar synthetic blood in people. "I'm very hopeful," Doctor says.
While promising, some experts remain cautious, noting that past attempts at artificial blood ultimately proved unsafe. "I think it's a reasonable approach," says Tim Estep, a scientist at Chart Biotech Consulting who consults with companies developing artificial blood. "But because this field has been so challenging, the proof will be in the clinical trials," he adds. "While I'm overall optimistic, placing a bet on any one technology right now is overall difficult."
Medicine

An Inventor Is Injecting Bleach Into Cancerous Tumors - and Wants to Bring the Treatment To the US (wired.com) 110

A Chinese inventor with no medical training is charging cancer patients $20,000 to inject highly concentrated chlorine dioxide -- a toxic bleach solution -- directly into their tumors, and is working with a former pharmaceutical executive to bring the unproven treatment to the United States, Wired reports.

Xuewu Liu uses injections containing 20,000 parts per million of chlorine dioxide, significantly higher than the 3,000 ppm concentrations typically found in oral bleach solutions peddled by pseudoscience promoters. One patient told WIRED her tumor grew faster after Liu's injections and suspects the treatment caused her cancer to spread to her skin.
Earth

'Boiling Frog' Effect Makes People Oblivious To Threat of Climate Crisis, Shows Study (theguardian.com) 186

An anonymous reader shares a report: Surveys show that the increasing number of extreme climate events, including floods, wildfires and hurricanes, has not raised awareness of the threats posed by climate change. Instead, people change their idea of what they see as normal. This so-called "boiling frog effect" makes gradual change difficult to spot.

Researchers at Carnegie Mellon University in Pennsylvania wondered if climate change could be made more obvious by presenting it in binary terms. Local newspaper archives describing ice skating on Lake Carnegie when it froze in winter inspired a simple experiment. Some test subjects were shown temperature graphs of a fictional town's winter conditions; others had a chart showing whether or not a fictional lake froze each year. The result, published in Nature, showed those who receiving the second graphic consistently saw climate change as more real and imminent.

Binary data gives a clearer impression of the "before" and "after." The disappearing ice is more vivid and dramatic than a temperature trace, even though the underlying data is the same. "We are literally showing them the same trend, just in different formats," says Rachit Dubey, a co-author of the study. These results should help drive more effective ways of communicating the impact of climate change in future by finding simple binary, black-and-white examples of its effects.

Science

Physicists Blow Up Gold With Giant Lasers, Accidentally Disprove Renowned Physics Model (gizmodo.com) 81

Physicists at SLAC National Accelerator Laboratory superheated gold to over 33,000F using giant lasers and X-rays -- far exceeding the limits set by long-standing physics models. From the report: In an experiment presented today in Nature, researchers, for the first time ever, demonstrated a way to directly measure the temperature of matter in extreme states, or conditions with intensely high temperatures, pressures, or densities. Using the new technique, scientists succeeded in capturing gold at a temperature far beyond its boiling point -- a procedure called superheating -- at which point the common metal existed in a strange limbo between solid and liquid. The results suggest that, under the right conditions, gold may have no superheating limit. If true, this could have a wide range of applications across spaceflight, astrophysics, or nuclear chemistry, according to the researchers.

The study is based on a two-pronged experiment. First, the scientists used a laser to superheat a sample of gold, suppressing the metal's natural tendency to expand when heated. Next, they used ultrabright X-rays to zap the gold samples, which scattered off the surface of the gold. By calculating the distortions in the X-ray's frequency after colliding with the gold particles, the team locked down the speed and temperature of the atoms.

The experimental result seemingly refutes a well-established theory in physics, which states that structures like gold can't be heated more than three times their boiling point, 1,948 degrees Fahrenheit (1,064 degrees Celsius). Beyond those temperatures, superheated gold is supposed to reach the so-called "entropy catastrophe" -- or, in more colloquial terms, the heated gold should've blown up. The researchers themselves didn't expect to surpass that limit. The new result disproves the conventional theory, but it does so in a big way by far overshooting the theoretical prediction, showing that it's possible to heat gold up to a jaw-dropping 33,740 degrees F (18,726 degrees C). [...] The team is already applying the technique to other materials, such as silver and iron, which they happily report produced some promising data.

Science

Sweet Spot For Daily Steps Is Lower Than Often Thought, New Study Finds (theconversation.com) 80

A massive review of over 160,000 people's step counts has revealed that meaningful health benefits begin far below the popular 10,000-step myth. The new study found that health benefits start at as low as 2,500 daily steps, with the biggest gains capping around 7,000. "People hitting 7,000 daily steps had a 47% lower risk of dying prematurely than those managing just 2,000 steps, plus extra protection against heart disease, cancer and dementia," reports The Conversation. From the report: The findings come from the biggest review of step counts and health ever done. Researchers gathered data from 57 separate studies tracking more than 160,000 people for up to two decades, then combined all the results to spot patterns that individual studies might miss. This approach, called a systematic review, gives scientists much more confidence in their conclusions than any single study could.

So where did that magic 10,000 number come from? A pedometer company called Yamasa wanted to cash in on 1964 Tokyo Olympics fever. It launched a device called Manpo-kei -- literally "10,000 steps meter." The Japanese character for 10,000 resembles a walking person, while 10,000 itself is a memorable round number. It was a clever marketing choice that stuck. At that time, there was no robust evidence for whether a target of 10,000 steps made sense. Early research suggested that jumping from a typical 3,000 to 5,000 daily steps to 10,000 would burn roughly 300 to 400 extra calories a day. So the target wasn't completely random -- just accidentally reasonable.

This latest research paper looked across a broad spectrum -- not just whether people died, but heart disease, cancer, diabetes, dementia, depression and even falls. The results tell a fascinating story. Even tiny increases matter. Jump from 2,000 to 4,000 steps daily and your death risk drops by 36%. That's a substantial improvement. But here's where it gets interesting. The biggest health benefits happen between zero and 7,000 steps. Beyond that, benefits keep coming, but they level off considerably. Studies have found meaningful benefits starting at just 2,517 steps per day. For some people, that could be as little as a 20-minute stroll around the block. Age changes everything, too. If you're over 60, you hit maximum benefits at 6,000 to 8,000 daily steps. Under 60? You need 8,000 to 10,000 steps for the same protection. Your 70-year-old neighbor gets 77% lower heart disease risk at just 4,500 steps daily.

The real secret of why fitness targets often fail? People give up on them. Research comparing different step goals found a clear pattern. Eighty-five per cent of people stuck with 10,000 daily steps. Bump it to 12,500 steps and only 77% kept going. Push for 15,000 steps and you lose nearly a third of people.

United States

US To Withdraw From UNESCO Again (nature.com) 118

The United States will withdraw from UNESCO for the second time in eight years, with the departure taking effect December 31, 2026. The State Department announced the decision yesterday, ending the country's brief two-year return to the Paris-based United Nations science and cultural organization. The US previously withdrew from UNESCO in 2017, cutting off more than 22% of the agency's funding. The American contribution now represents 8% of UNESCO's current $900 million annual budget, making the financial impact less severe than the earlier withdrawal.

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