An anonymous reader quotes a report from Reuters: SpaceX's workhorse Falcon 9 rocket was grounded by the U.S. Federal Aviation Administration (FAA) on Friday after one broke apart in space and doomed its payload of Starlink satellites, the first failure in more than seven years of a rocket relied upon by the global space industry. Roughly an hour after Falcon 9 lifted off from the Vandenberg Space Force Base in California on Thursday night, the rocket's second stage failed to reignite and deployed its 20 Starlink satellites on a shallow orbital path where they will soon reenter and burn up in Earth's atmosphere.

The attempt to reignite the engine "resulted in an engine RUD for reasons currently unknown," SpaceX CEO Elon Musk wrote early on Friday on his social media platform X, using an industry acronym for Rapid Unscheduled Disassembly that usually means explosion. The Falcon 9 will be grounded until SpaceX investigates the cause of the failure, fixes the rocket and receives the agency's approval, the FAA said in a statement. That process could take several weeks or months, depending on the complexity of the failure and SpaceX's plan to fix it. Musk said SpaceX was updating the software of the Starlink satellites to force their on-board thrusters to fire harder than usual to avoid a fiery atmospheric re-entry. "Unlike a Star Trek episode, this will probably not work, but it's worth a shot," Musk said.

The satellites' altitude is so shallow that Earth's gravity is pulling them 3 miles (5 km) closer toward the atmosphere with each orbit, SpaceX later said, confirming they would inevitably "re-enter Earth's atmosphere and fully demise." SpaceX said the second stage's failure occurred after engineers detected a leak of liquid oxygen, a propellant. The mishap occurred on Falcon 9's 354th mission. It was the first Falcon 9 failure since 2016, when a rocket exploded on a launch pad in Florida and destroyed its customer payload, an Israeli communications satellite. The failure "breaks a success streak of more than 300 straight missions," notes Reuters.

"We knew this incredible run had to come to an end at some point," Tom Mueller, SpaceX's former vice president of propulsion who designed Falcon 9's engines. "... The team will fix the problem and start the cycle again."

Scientists say "a reservoir of disease" is being created after discovering bacteria that naturally occur in rivers are becoming resistant to antibiotics due to the impact of sewage. From a report: Researchers at the University of Suffolk said bacterial strains found on the non-tidal section of the River Deben in Suffolk had acquired resistance by exchanging DNA with antibiotic resistant E. coli. Some bacteria have become resistant to the antibiotic carbapenem, which is used as the last line of defence in fighting infections already resistant to traditional antibiotics. Dr Nick Tucker, a microbiologist leading the research, described the discovery as "particularly worrying."

"Organisms that are currently low risk are being mixed with pathogenic organisms from sewage," he said. "We're needlessly adding pathogenic and virulence genes to bacteria found in the environment, and that could be creating a reservoir of disease." The team has been working closely with citizen scientists from the Deben Climate Centre, who have been taking water samples for two years. They have also been working with scientists at the government's CEFAS laboratories, who have helped identify the new strains that are being screened for their resistance to six of the most commonly-used antibiotics. The River Deben rises in Debenham, Suffolk, before flowing through Woodbridge and down to the North Sea.

The Conversation: Reading and writing articles published in academic journals and presented at conferences is a central part of being a researcher. When researchers write a scholarly article, they must cite the work of peers to provide context, detail sources of inspiration and explain differences in approaches and results. A positive citation by other researchers is a key measure of visibility for a researcher's own work. But what happens when this citation system is manipulated? A recent Journal of the Association for Information Science and Technology article by our team of academic sleuths -- which includes information scientists, a computer scientist and a mathematician -- has revealed an insidious method to artificially inflate citation counts through metadata manipulations: sneaked references.

People are becoming more aware of scientific publications and how they work, including their potential flaws. Just last year more than 10,000 scientific articles were retracted. The issues around citation gaming and the harm it causes the scientific community, including damaging its credibility, are well documented. Citations of scientific work abide by a standardized referencing system: Each reference explicitly mentions at least the title, authors' names, publication year, journal or conference name, and page numbers of the cited publication. These details are stored as metadata, not visible in the article's text directly, but assigned to a digital object identifier, or DOI -- a unique identifier for each scientific publication.

References in a scientific publication allow authors to justify methodological choices or present the results of past studies, highlighting the iterative and collaborative nature of science. However, we found through a chance encounter that some unscrupulous actors have added extra references, invisible in the text but present in the articles' metadata, when they submitted the articles to scientific databases. The result? Citation counts for certain researchers or journals have skyrocketed, even though these references were not cited by the authors in their articles.

A group of astronomers want to change the definition of a planet. Their new proposed definition wouldn't bring Pluto back into the planetary fold, but it could reclassify thousands of celestial bodies across the universe. From a report: The International Astronomical Union's (IAU) current definition of a planet, established in 2006, includes only celestial bodies that are nearly round, are gravitationally dominant and orbit our Sun. This Sun-centric definition excludes all of the bodies we've discovered outside our solar system, even if they may fit all other parameters. They are instead considered exoplanets. Those behind the new proposal critiqued the IAU's definition in an upcoming paper in the Planetary Science Journal, arguing it's vague, not quantitative and unnecessarily exclusionary.

Their new proposal would instead classify planets based on their mass, considering a planet to be any celestial body that:
1. orbits one or more stars, brown dwarfs or stellar remnants and,
is more massive than 10ÂÂ kilograms (kg) and,
is less massive than 13 Jupiter masses (2.5 X 10^28Âkg).

Aryan Kapoor, a high schooler from JRD Propulsion, successfully developed a model rocket with SpaceX-style vertical landing capabilities. The three-year effort was made possible by a thrust-vector control and clever landing gear design. Hackaday reports: He started in 2021 with none of the basic skills needed to pull off something like this, but it seems like he quickly learned the ropes. His development program was comprehensive, with static test vehicles, a low-altitude hopper, and extensive testing of the key technology: thrust-vector control. His rocket uses two solid-propellant motors stacked on top of each other, one for ascent and one for descent and landing. They both live in a 3D printed gimbal mount with two servos that give the stack plus and minus seven degrees of thrust vectoring in two dimensions, which is controlled by a custom flight computer with a barometric altimeter and an inertial measurement unit. The landing gear is also clever, using rubber bands to absorb landing forces and syringes as dampers. You can watch the first successful test flight and landing on YouTube.

The idea that night owls who don't go to bed until the early hours struggle to get anything done during the day may have to be revised. From a report: It turns out that staying up late could be good for our brain power as research suggests that people who identify as night owls could be sharper than those who go to bed early. Researchers led by academics at Imperial College London studied data from the UK Biobank study on more than 26,000 people who had completed intelligence, reasoning, reaction time and memory tests.

They then examined how participants' sleep duration, quality, and chronotype (which determines what time of day we feel most alert and productive) affected brain performance. They found that those who stay up late and those classed as "intermediate" had "superior cognitive function," while morning larks had the lowest scores. Going to bed late is strongly associated with creative types.

A recent study has exposed a method of artificially inflating citation counts through "sneaked references," which are extra citations included in metadata but not in the actual text of articles. This manipulation, uncovered in journals by Technoscience Academy, distorts citation metrics that are critical for research funding and academic promotions. The Conversation reports: The investigation began when Guillaume Cabanac, a professor at the University of Toulouse, wrote a post on PubPeer, a website dedicated to post-publication peer review, in which scientists discuss and analyze publications. In the post, he detailed how he had noticed an inconsistency: a Hindawi journal article that he suspected was fraudulent because it contained awkward phrases had far more citations than downloads, which is very unusual. The post caught the attention of several sleuths who are now the authors of the JASIST article. We used a scientific search engine to look for articles citing the initial article. Google Scholar found none, but Crossref and Dimensions did find references. The difference? Google Scholar is likely to mostly rely on the article's main text to extract the references appearing in the bibliography section, whereas Crossref and Dimensions use metadata provided by publishers.

To understand the extent of the manipulation, we examined three scientific journals that were published by the Technoscience Academy, the publisher responsible for the articles that contained questionable citations. [...] In the journals published by Technoscience Academy, at least 9% of recorded references were "sneaked references." These additional references were only in the metadata, distorting citation counts and giving certain authors an unfair advantage. Some legitimate references were also lost, meaning they were not present in the metadata. In addition, when analyzing the sneaked references, we found that they highly benefited some researchers. For example, a single researcher who was associated with Technoscience Academy benefited from more than 3,000 additional illegitimate citations. Some journals from the same publisher benefited from a couple hundred additional sneaked citations.

We wanted our results to be externally validated, so we posted our study as a preprint, informed both Crossref and Dimensions of our findings and gave them a link to the preprinted investigation. Dimensions acknowledged the illegitimate citations and confirmed that their database reflects Crossref's data. Crossref also confirmed the extra references in Retraction Watch and highlighted that this was the first time that it had been notified of such a problem in its database. The publisher, based on Crossref's investigation, has taken action to fix the problem. To combat this practice of "sneaked references," the authors suggest several measures: rigorous verification of metadata by publishers and agencies like Crossref, independent audits to ensure data reliability, and increased transparency in managing references and citations.

Longtime Slashdot reader ArchieBunker shares a report from TIME Magazine: On an evening in December 2023, 43-year-old small business owner Sarah Rosenkranz collapsed in her home in Granbury, Texas and was rushed to the emergency room. Her heart pounded 200 beats per minute; her blood pressure spiked into hypertensive crisis; her skull throbbed. "It felt like my head was in a pressure vise being crushed," she says. "That pain was worse than childbirth." Rosenkranz's migraine lasted for five days. Doctors gave her several rounds of IV medication and painkiller shots, but nothing seemed to knock down the pain, she says. This was odd, especially because local doctors were similarly vexed when Indigo, Rosenkranz's 5-year-old daughter, was taken to urgent care earlier that year, screaming that she felt a "red beam behind her eardrums." It didn't occur to Sarah that these symptoms could be linked. But in January 2024, she walked into a town hall in Granbury and found a room full of people worn thin from strange, debilitating illnesses. A mother said her 8-year-old daughter was losing her hearing and fluids were leaking from her ears. Several women said they experienced fainting spells, including while driving on the highway. Others said they were wracked by debilitating vertigo and nausea, waking up in the middle of the night mid-vomit. None of them knew what, exactly, was causing these symptoms. But they all shared a singular grievance: a dull aural hum had crept into their lives, which growled or roared depending on the time of day, rattling their windows and rendering them unable to sleep. The hum, local law enforcement had learned, was emanating from a Bitcoin mining facility that had recently moved into the area -- and was exceeding legal noise ordinances on a daily basis.

Over the course of several months in 2024, TIME spoke to more than 40 people in the Granbury area who reported a medical ailment that they believe is connected to the arrival of the Bitcoin mine: hypertension, heart palpitations, chest pain, vertigo, tinnitus, migraines, panic attacks. At least 10 people went to urgent care or the emergency room with these symptoms. The development of large-scale Bitcoin mines and data centers is quite new, and most of them are housed in extremely remote places. There have been no major medical studies on the impacts of living near one. But there is an increasing body of scientific studies linking prolonged exposure to noise pollution with cardiovascular damage. And one local doctor -- ears, nose, and throat specialist Salim Bhaloo -- says he sees patients with symptoms potentially stemming from the Bitcoin mine's noise on an almost weekly basis. "I'm sure it increases their cortisol and sugar levels, so you're getting headaches, vertigo, and it snowballs from there," Bhaloo says. "This thing is definitely causing a tremendous amount of stress. Everyone is just miserable about it." "By the end of 2024, we intend to have replaced the majority of air-cooled containers with immersion cooling, with no expansion required," said a representative for Marathon Digital Holdings, the company that owns the mine. "Initial sound readings on immersion containers indicate favorable results in sound reduction and compliance with all relevant state noise ordinances." They did not answer questions about the health impacts their mining site was causing.

"We're living in a nightmare," said Rosenkranz. She clocked the hum at 72 decibels in Indigo's bedroom in the dead of night. "Indigo's room directly faces the mine, which sits about a mile and a half away," notes TIME. She had to be pulled from her school after she developed so many ear infections from the sound.

The report also said a resident's dog "started going bald and developed debilitating anxiety shortly after the Bitcoin mine began operating four blocks away." TIME added: "Directly next door, Tom Weeks' dog Jack Rabbit Slim started shaking and hyperventilating uncontrollably for hours on end; a vet placed him on the seizure medication Gabapentin. Rosenkranz's chickens stopped laying eggs for months. And Jerry and Patricia Campbell's centuries-old oak tree, which had served as the family's hub and protector for generations of backyard family reunions and even a wedding, died suddenly three months ago."

OpenAI CEO Sam Altman and businesswoman Arianna Huffington have announced they're working on an "AI health coach" via Thrive AI Health. According to a Time magazine op-ed, the two executives said that the bot will be trained on "the best peer-reviewed science" alongside "the personal biometric, lab, and other medical data you've chosen to share with it." The Verge reports: The company tapped DeCarlos Love, a former Google executive who previously worked on Fitbit and other wearables, to be CEO. Thrive AI Health also established research partnerships with several academic institutions and medical centers like Stanford Medicine, the Rockefeller Neuroscience Institute at West Virginia University, and the Alice L. Walton School of Medicine. (The Alice L. Walton Foundation is also a strategic investor in Thrive AI Health.) Thrive AI Health's goal is to provide powerful insights to those who otherwise wouldn't have access -- like a single mother looking for quick meal ideas for her gluten-free child or an immunocompromised person in need of instant advice in between doctor's appointments. [...]

The bot is still in its early stages, adopting an Atomic Habits approach. Its goal is to gently encourage small changes in five key areas of your life: sleep, nutrition, fitness, stress management, and social connection. By making minor adjustments, such as suggesting a 10-minute walk after picking up your child from school, Thrive AI Health aims to positively impact people with chronic conditions like heart disease. It doesn't claim to be ready to provide real diagnosis like a doctor would but instead aims to guide users into a healthier lifestyle. "AI is already greatly accelerating the rate of scientific progress in medicine -- offering breakthroughs in drug development, diagnoses, and increasing the rate of scientific progress around diseases like cancer," the op-ed read.

Starting this fall, most students at Johns Hopkins' medical school will attend tuition-free thanks to a $1 billion donation from billionaire Mike Bloomberg. From a report: The generous gift is intended to address "twin challenges of declining levels of health and education," Bloomberg said in a letter Monday. The donation will cover the full cost of tuition for medical students from families earning less than $300,000, Bloomberg Industries announced Monday. It will also cover living expenses and other fees for students from families earning up to $175,000.

Currently, nearly two-thirds of medical students at the school qualify for financial aid. Johns Hopkins' medical students graduate with an average student loan debt of about $104,000. The donation will also increase financial aid at some of the university's other graduate schools, including the schools of nursing and public health.

A controversial organ retrieval technique is gaining traction across the U.S., promising to alleviate chronic organ shortages but also sparking intense ethical debates, NPR reports. Normothermic regional perfusion, now used by half of the nation's organ procurement organizations, restores blood flow to organs after cardiac death. Proponents argue it increases viable organ supply and improves transplant outcomes. Critics, however, question whether the procedure blurs the definition of death.

An anonymous reader quotes a report from The Guardian: Air pollution exposure can significantly decrease the chance of a live birth after IVF treatment, according to research that deepens concern about the health impacts of toxic air on fertility. Pollutant exposure has previously been linked to increased miscarriage rates and preterm births, and microscopic soot particles have been shown to travel through the bloodstream into the ovaries and the placenta. The latest work suggests that the impact of pollution begins before conception by disrupting the development of eggs. "We observed that the odds of having a baby after a frozen embryo transfer were more than a third lower for women who were exposed to the highest levels of particulate matter air pollution prior to egg collection, compared with those exposed to the lowest levels," said Dr Sebastian Leathersich, a fertility specialist and gynaecologist from Perth who is due to present the findings on Monday at the European Society of Human Reproduction and Embryology annual meeting in Amsterdam. [...]

The study analyzed fertility treatments in Perth over an eight-year period, including 3,659 frozen embryo transfers from 1,836 patients, and tracked whether outcomes were linked to the levels of fine particulate matter, known as PM10. The overall live birthrate was about 28% per transfer. However, the success rates varied in line with exposure to pollutants in the two weeks leading up to egg collection. The odds of a live birth decreased by 38% when comparing the highest quartile of exposure to the lowest quartile. "These findings suggest that pollution negatively affects the quality of the eggs, not just the early stages of pregnancy, which is a distinction that has not been previously reported," Leathersich said. The team now plan to study cells directly to understand why pollutants have a negative effect. Previous work has shown that the microscopic particles can damage DNA and cause inflammation in tissues. The report notes that the link between air pollution and live birth "was apparent despite excellent overall air quality during the study period, with PM10 and PM2.5 levels exceeding WHO guidelines on just 0.4% and 4.5% of the study days."

It adds: "Australia is one of just seven countries that met the WHO's guidelines in 2023, and this study is the latest to show evidence of harm even at relatively low levels of pollution."

The study has been published in the journal Human Reproduction.

The world has baked for 12 consecutive months in temperatures 1.5C (2.7F) greater than their average before the fossil fuel era, new data shows. Temperatures between July 2023 and June 2024 were the highest on record, scientists found, creating a year-long stretch in which the Earth was 1.64C hotter than in preindustrial times. From a report: The findings do not mean world leaders have already failed to honour their promises to stop the planet heating 1.5C by the end of the century -- a target that is measured in decadal averages rather than single years -- but that scorching heat will have exposed more people to violent weather. A sustained rise in temperatures above this level also increases the risk of uncertain but catastrophic tipping points.

Carlo Buontempo, director of the Copernicus Climate Change Service, which analysed the data, said the results were not a statistical oddity but a "large and continuing shift" in the climate. "Even if this specific streak of extremes ends at some point, we are bound to see new records being broken as the climate continues to warm," he said. "This is inevitable unless we stop adding greenhouse gases into the atmosphere and the oceans." Copernicus, a scientific organisation that belongs to the EU's space programme, uses billions of measurements from satellites, ships, aircraft and weather stations to track key climate metrics. It found June 2024 was hotter than any other June on record and was the 12th month in a row with temperatures 1.5C greater than their average between 1850 and 1900. Because temperatures in some months had "relatively small margins" above 1.5C, the scientists said, datasets from other climate agencies may not confirm the 12-month temperature streak.

A Wall Street Journal analysis has revealed that private insurers in the government's Medicare Advantage program, including UnitedHealth Group, have made numerous questionable diagnoses leading to increased taxpayer-funded payments between 2018 and 2021.

The investigation found instances where patients were diagnosed with conditions they did not have, such as diabetic cataracts and HIV, often without their knowledge. These diagnoses resulted in higher payments from Medicare to the insurers. The Centers for Medicare and Medicaid Services said they are implementing changes to ensure "taxpayer dollars are appropriately spent." The story adds: In all, Medicare paid insurers about $50 billion for diagnoses added just by insurers in the three years ending in 2021, the Journal's analysis showed.

"Russia has finally admitted that American astronauts did, in fact, land on the moon," reports Newsweek: Head of Russian Space Corporation Roscosmos, Yuri Borisov, accepted the truth of the U.S. putting a man on the moon in an address to the State Duma, Intellinews has reported.

"As for whether the Americans were on the Moon or not, I have one fact to share," he was reported to have said. "I was personally interested in this matter. At one time, they provided us with a portion of the lunar soil that the astronauts brought back during their expedition." Previous polling revealed that just under half of Russians believe America's 1969 moon landing was a government hoax. However, Borisov said that tests performed on the samples by the Russian Academy of Scientists confirmed their authenticity.

They lived 378 days in a "mock Mars habitat" in Houston, reports Engadget. But today the four volunteers for NASA's yearlong simulation will finally emerge from their 1,700-square-foot habitat at the Johnson Space Center that was 3D-printed from materials that could be created with Martian soil.

And you can watch the "welcome home" ceremony's livestream starting at 5 p.m. EST on NASA TV (also embedded in Engadget's story). More det ails from NASA: For more than a year, the crew simulated Mars mission operations, including "Marswalks," grew and harvested several vegetables to supplement their shelf-stable food, maintained their equipment and habitat, and operated under additional stressors a Mars crew will experience, including communication delays with Earth, resource limitations, and isolation.
One of the mission's crew members told the Houston Chronicle they were "very excited to go back to 'Earth,' but of course there is a bittersweet aspect to it just like any time you reach the completion of something that has dominated one's life for several years."

Various crew members left behind their children or long-term partner for this once-in-a-lifetime experience, according to an earlier article, which also notes that NASA is paying the participants $10 per hour "for all waking hours, up to 16 hours per day. That's as much as $60,480 for the 378-day mission."

Engadget points out there are already plans for two more one-year "missions" — with the second one expected to begin next spring...

I'm curious. Would any Slashdot readers be willing to spend a year in a mock Mars habitat?

New York City announced a "major citywide initiative" to increase "math achievement" among students, according to the mayor's office.

93 middle schools and 420 high schools will implement an "Illustrative Math" curriculum (from an education nonprofit founded in 2011) combined with intensive teacher coaching, starting this fall. "The goal is to ensure that all New York City students develop math skills," according to the NYC Solves web site (with the mayor's office noting "years of stagnant math scores.") Long-time Slashdot reader theodp writes: The NYC Public Schools further explained, "As part of the NYC Solves initiative, all high schools will use Illustrative Mathematics and districts will choose a comprehensive, evidence-based curricula for middle school math instruction from an approved list. Each curriculum has been reviewed and recommended by EdReports, a nationally recognized nonprofit organization."

The About page for Illustrative Mathematics (IM) lists The Bill & Melinda Gates Foundation as a Philanthropic Supporter [as well as the Chan Zuckerberg Initiative and The William and Flora Hewlett Foundation], and lists two Gates Foundation Directors as Board members... A search of Gates Foundation records for "Illustrative Mathematics" turns up $25 million in committed grants since 2012, including a $13.9 million grant to Illustrated Mathematics in Nov. 2022 ("To support the implementation of high-quality instructional materials and practices for improving students' math experience and outcomes") and a $425,000 grant just last month to Educators for Excellence ("To engage teacher feedback on the implementation of Illustrative Mathematics curriculum and help middle school teachers learn about the potential for math high-quality instructional materials and professional learning in New York City").

EdReports, which vouched for the Illustrative Mathematics curriculum (according to New York's Education Department), has received $10+ million in committed Gates Foundation grants. The Gates Foundation is also a very generous backer of NYC's Fund for Public Schools, with grants that included $4,276,973 in October 2023 "to support the implementation of high-quality instructional materials and practices for improving students' math experience and outcomes."

Chalkbeat reported in 2018 on a new focus on high school curriculum by the Gates Foundation ("an area where we feel like we've underinvested," said Bill Gates). The Foundation made math education its top K-12 priority in Oct. 2022 with a $1.1 billion investment. Also note this May 2023 blog post from $14+ million Gates Foundation grantee Educators for Excellence, a New York City nonprofit. The blog post touts the key role the nonprofit had played in a year-long advocacy effort that ultimately "secured a major win" ending the city's curricula "free-for-all" and announced "a standardized algebra curriculum from Illustrative Mathematics will also be piloted at 150 high schools."

As the NY Times reported back in 2011, behind "grass-roots" school advocacy, there's Bill Gates!

Longtime Slashdot reader Baron_Yam shares a report from Phys.Org, with the caption: "It's not sequestration, but it is a closed carbon loop and can store energy from renewable sources to be released when they are not collecting energy." From the report: Carbon in the atmosphere is a major driver of climate change. Now researchers from McGill University have designed a new catalyst for converting carbon dioxide (CO2) into methane -- a cleaner source of energy -- using tiny bits of copper called nanoclusters. While the traditional method of producing methane from fossil fuels introduces more CO2 into the atmosphere, the new process, electrocatalysis, does not. "On sunny days you can use solar power, or when it's a windy day you can use that wind to produce renewable electricity, but as soon as you produce that electricity you need to use it," says Mahdi Salehi, Ph.D. candidate at the Electrocatalysis Lab at McGill University. "But in our case, we can use that renewable but intermittent electricity to store the energy in chemicals like methane."

By using copper nanoclusters, says Salehi, carbon dioxide from the atmosphere can be transformed into methane and once the methane is used, any carbon dioxide released can be captured and "recycled" back into methane. This would create a closed "carbon loop" that does not emit new carbon dioxide into the atmosphere. The research, published recently in the journal Applied Catalysis B: Environment and Energy, was enabled by the Canadian Light Source (CLS) at the University of Saskatchewan (USask). The team plans to continue refining their catalyst to make it more efficient and investigate its large-scale, industrial applications. Their hope is that their findings will open new avenues for producing clean, sustainable energy.

An anonymous reader quotes a report from CNN: Deep inside Earth is a solid metal ball that rotates independently of our spinning planet, like a top whirling around inside a bigger top, shrouded in mystery. This inner core has intrigued researchers since its discovery by Danish seismologist Inge Lehmann in 1936, and how it moves -- its rotation speed and direction -- has been at the center of a decades-long debate. A growing body of evidence suggests the core's spin has changed dramatically in recent years, but scientists have remained divided over what exactly is happening -- and what it means. Part of the trouble is that Earth's deep interior is impossible to observe or sample directly. Seismologists have gleaned information about the inner core's motion by examining how waves from large earthquakes that ping this area behave. Variations between waves of similar strengths that passed through the core at different times enabled scientists to measure changes in the inner core's position and calculate its spin.

"Differential rotation of the inner core was proposed as a phenomenon in the 1970s and '80s, but it wasn't until the '90s that seismological evidence was published," said Dr. Lauren Waszek, a senior lecturer of physical sciences at James Cook University in Australia. But researchers argued over how to interpret these findings, "primarily due to the challenge of making detailed observations of the inner core, due to its remoteness and limited available data," Waszek said. As a result, "studies which followed over the next years and decades disagree on the rate of rotation, and also its direction with respect to the mantle," she added. Some analyses even proposed that the core didn't rotate at all.

One promising model proposed in 2023 described an inner core that in the past had spun faster than Earth itself, but was now spinning slower. For a while, the scientists reported, the core's rotation matched Earth's spin. Then it slowed even more, until the core was moving backward relative to the fluid layers around it. At the time, some experts cautioned that more data was needed to bolster this conclusion, and now another team of scientists has delivered compelling new evidence for this hypothesis about the inner core's rotation rate. Research published June 12 in the journal Nature not only confirms the core slowdown, it supports the 2023 proposal that this core deceleration is part of a decades-long pattern of slowing down and speeding up. The new findings also confirm that the changes in rotational speed follow a 70-year cycle, said study coauthor Dr. John Vidale, Dean's Professor of Earth Sciences at the University of Southern California's Dornsife College of Letters, Arts and Sciences.

No leap second will be added to universal time in 2024, the International Earth Rotation and Reference Systems Service (IERS) has announced. From a report: An additional second has previously been added to the universal time as displayed by atomic clocks (UTC) when this measurement has become out of sync with the rotation of the Earth (UT1).

But in a statement released on Thursday, the IERS, which enacts changes to UTC on behalf of the International Telecommunications Union (ITU), said the difference between UTC and UT1 is not great enough to warrant a change. Changes in the relationship between UTC and UT1 sometimes occur because the Earth does not always spin at the same speed, with natural events such as earthquakes often causing small changes.