Physicists have proposed a new kind of atomic clock based on a revived superradiant laser concept that could produce an extraordinarily stable signal with a linewidth around 100 microhertz, potentially the narrowest ever for an optical laser. "The implications of this result could stretch well beyond timekeeping," reports Phys.org. "A laser immune to environmental frequency shifts would be a powerful tool in optical interferometry -- using interference patterns in light to make ultra-precise measurements." From the report: In a conventional laser, a mirrored cavity bounces light back and forth between atoms, building up a bright, coherent beam. A superradiant laser works differently: rather than relying on the cavity to maintain coherence, the atoms themselves act as single coordinated emitters, collectively synchronizing their light emission. Following early theoretical ideas emerged in the 1990s, the concept didn't gain concrete traction until 2008, when researchers at the University of Colorado proposed that superradiant lasers could serve as a new kind of atomic clock.

Atomic clocks work by using laser light to probe a very precise transition in an atom, causing electrons to transition between energy levels at an extraordinarily stable frequency. Because a superradiant laser stores its coherence in the atoms rather than the cavity, its output frequency is far less vulnerable to environmental disturbances like vibrations or temperature fluctuations. Yet although this concept was first demonstrated experimentally in 2012 in a pulsed regime, the influence of heating has so far held superradiant lasers back from their full potential. To keep the laser running continuously as an atomic clock requires, atoms must be constantly replenished with energy. Doing this atom-by-atom delivers random kicks that heat the atomic sample and disrupt the lasing process, confining it to brief pulses rather than a steady beam.

In their study, Reilly's team considered whether a modification to earlier theoretical concepts could make a continuous laser suitable for an atomic clock. In almost all previous studies, atoms were treated as simple two-level systems: an electron sitting in a ground state, occasionally jumping up to an excited state and back again. The team proposed that the heating problem could be solved by adding one extra ground state to the picture. In a two-level system, if both the pumping (re-energizing) and decay processes happen collectively through the cavity, the mathematics constrains the system in a way that prevents stable, continuous lasing. But with three levels available, pumping and decay can operate on entirely separate transitions, breaking that constraint and allowing the collective approach to work. The findings have been published in the journal Physical Review Letters.

An anonymous reader quotes a report from NPR: The Food and Drug Administration approved the first gene therapy to restore hearing for people who were born deaf. The decision, while only immediately affecting people born with a very rare form of genetic deafness, is being hailed as a milestone in the quest to treat hearing loss. "It's the first time in history there's a new drug for hearing loss," says Zheng-Yi Chen, an associate scientist at Mass Eye and Ear in Boston who was not involved in the development of the therapy approved by the FDA Thursday. But his research team reported very promising results with a similar approach Wednesday. "I think it's an historical event, a landmark, a great development for the whole field," he says of the approval. [...] The FDA's decision was based on the results from the treatment of 20 patients born with a defective version of a gene known as OTOF, which is necessary to transmit sound from the ears to the brain.

Doctors infused billions of adeno-associated viruses into the patients' ears by making a small incision behind the ear to open a small hole in the skull. The viruses carried a healthy version of the OTOF gene that had been split in half to fit inside the virus. The gene provides instructions to make the otoferlin protein, which is necessary for hair cells in the inner ear to transmit sound to the brain. Most of the patients began to hear for the first time within weeks, with the quality of their hearing improving over the following months, according to [Regeneron Pharmaceuticals, which developed the gene therapy and plans to offer it for free in the U.S. It should be available within weeks.]. The amount of hearing patients gained varied, but 80% achieved at least some significant hearing restoration and 42% ended up with normal hearing, which included the ability to hear whispers, Regeneron says. The hearing ability has lasted at least two years so far.

The treatment can only help patients with the very rare form of deafness that Smith was born with, which only affects about 50 children each year in the U.S. But similar gene therapies are showing promise for other forms of genetic deafness. And researchers hope someday gene therapy may help with common types of hearing loss, like from aging and loud noise.

An anonymous reader quotes a report from the Guardian: Nearly half of children in the United States are breathing dangerous levels of air pollution, according to a new report, as experts warned Donald Trump's expansive rollback of protections will make the situation worse. The 27th annual air quality report from the American Lung Association (ALA) released on Wednesday evaluates pollution across the country by grading levels of ground-level ozone -- also known as smog -- as well as year-round and short-term spikes in particle pollution, commonly referred to as soot. The report analyzed quality-assured data collected between 2022 and 2024. It found that 33.5 million children in the US -- 46% of those under 18 -- live in areas that received a failing grade for at least one measure of air pollution. The report also found that 7 million children, or 10% of all children in the US, live in communities that failed all three measures.

The report further found that communities of color are disproportionately exposed to unhealthy air. As a result, they are more likely to live with one or more chronic health conditions that make them more vulnerable to pollution, including asthma, diabetes, and heart disease. Although people of color make up 42.1% of the US population, they represent 54.2% of those living in counties with at least one failing grade, the report noted. It also found that a person of color is 2.42 times more likely than a white person to live in a community that fails all three pollution measures. Smog remains the most widespread pollutant affecting Americans' health. Between 2022 and 2024, 38% of the US population -- approximately 129.1 million people -- were exposed to ozone levels that put their health at risk. This marks the highest number recorded in the ALA's report in six years, and a 3.9 million increase from the previous year.

Several factors contributed to these unhealthy pollution levels, including extreme heat, drought and wildfires which have exposed a growing share of the population to harmful ozone, the report said. The regions most affected by high ozone levels include south-western states from California to Texas, as well as much of the midwest. This is mainly driven by smoke from Canada's 2023 wildfires crossing into the US, along with high temperatures and weather patterns that favored ozone formation in 2023 and 2024 -- particularly in southern states. More broadly, the report found that climate change is intensifying ozone pollution by boosting precursor emissions and creating atmospheric conditions such as higher temperatures and lower wind speeds that allow pollutants to build up and ozone to form. Another growing source of pollution: datacenters. The report notes how they rely on regional electricity grids where fossil fuels like methane gas and coal still account for a large portion of generation. Many datacenters also use dozens of large diesel-powered backup generators, which emit carcinogenic particulate matter.

"Children's lungs are still developing," said Will Barrett, assistant vice-president of the ALA's Nationwide Clean Air Policy. "For their body size, they're breathing more air. And also, kids play outdoors, they're more active, they're breathing in more outdoor air [...]. So, air pollution exposure in children can contribute to long-term developmental harm to their lungs, new cases of asthma, increased risks of respiratory illness and other health considerations later in life."

NASA's Curiosity rover has identified a diverse set of organic molecules on Mars, including a nitrogen-bearing compound similar in structure to DNA precursors. The finding strengthens the case that ancient organic material can survive in the Martian subsurface, though it does not prove past life because the compounds could also come from geology or meteorites. Phys.org reports: The study was led by Amy Williams, Ph.D., a professor of geological sciences at the University of Florida and a scientist on the Curiosity and Perseverance Mars rover missions. Curiosity landed on Mars in 2012 to find evidence that ancient Mars had conditions that could support microbial life billions of years ago; the Perseverance rover, which landed in 2021, was sent to look for signs of any ancient life that might have formed.

Among the 20-plus chemicals identified by the experiment, Curiosity spotted a nitrogen-bearing molecule with a structure similar to DNA precursors -- a chemical never before spotted on Mars. The rover also identified benzothiophene, a large, double-ringed, sulfurous chemical often delivered to planets by meteorites. "The same stuff that rained down on Mars from meteorites is what rained down on Earth, and it probably provided the building blocks for life as we know it on our planet," Williams said. The findings have been published in the journal Nature Communications.

Federal authorities are now reviewing a string of deaths and disappearances involving scientists tied to sensitive U.S. aerospace and nuclear work, though officials have not established any confirmed link between the cases. The FBI says it "is spearheading the effort to look for connections into the missing and deceased scientists," adding that it "is working with the Department of Energy, Department of War, and with our state ... and local law enforcement partners to find answers." The Republican-led House Oversight Committee also announced an investigation into the reports. CNN reports: A nuclear physicist and MIT professor fatally shot outside his Massachusetts residence. A retired Air Force general missing from his New Mexico home. An aerospace engineer who disappeared during a hike in Los Angeles. These are among at least 10 individuals connected to sensitive US nuclear and aerospace research who have died or disappeared in recent years, prompting concerns whether they are connected and fueling speculation online about the possibility of nefarious activity. [...]

The Defense Department said only that it would respond to the committee directly, and the Department of Energy referred questions to the White House. In a post on X, NASA said it is "coordinating and cooperating with the relevant agencies" in relation to the scientists. "At this time, nothing related to NASA indicates a national security threat," NASA spokesperson Bethany Stevens said.

The cases vary widely in circumstance. Some involve unsolved homicides, while others are missing persons cases with no signs of foul play. In at least two instances, families have pointed to preexisting medical conditions or personal struggles as explanations. Authorities have not established any links between the cases. The White House said last week it is also working with federal agencies to probe any potential links between the deaths and disappearances, with President Donald Trump referring to the matter as "pretty serious stuff." "The United States has thousands of nuclear scientists and nuclear experts," said Rep. James Walkinshaw, a Democrat who also serves on the Oversight Committee. "It's not the kind of nuclear program that potentially a foreign adversary could significantly impact by targeting 10 individuals."

Further reading: The 'Missing-Scientist' Story Is Unbelievably Dumb

NASA astronaut Reid Wiseman posted an out-of-this-world iPhone video on Sunday, showing Earth disappear behind the Moon at 8x zoom. "I could barely see the Moon through the docking hatch window but the iPhone was the perfect size to catch the view," said Wiseman, noting that this video is "uncropped, uncut with 8x zoom" and "quite comparable to the view of the human eye." The New York Times says the video marks the first time an "Earthset" has been captured on video.

"We've seen our fair share of remarkable images and videos from NASA's Artemis II mission around the Moon. Some of those were even captured on iPhone," notes 9to5Mac. "But Reid Wiseman, astronaut and commander for the Artemis II mission, just posted a new video that might take the crown for the most impressive yet."

SpaceNews reports: Blue Origin's New Glenn suffered a malfunction of its second stage on the rocket's third flight April 19, stranding its payload in an unrecoverable "off-nominal" orbit and dealing the company a setback as it seeks to increase its flight rate... AST SpaceMobile had planned to launch 45 to 60 satellites this year for its D2D constellation, but BlueBird 7 is the first to launch since BlueBird 6 launched on an Indian LVM3 rocket in December.
AST SpaceMobile still expects to have 45 satellites in orbit by the end of the year, the article notes. (In an earnings call in March, AST SpaceMobile's CEO had promised they'd soon start "stacking" satellites, "batched in groups of either three, four, six or eight in a single launch.") He'd added that "To support our launch cadence during 2026, we expect the New Glenn booster to be reused every 30 days or less..."

There's some good news there, SpaceNews points out, since today saw the first successful reflight of a New Glenn first stage rocket: The booster, called "Never Tell Me The Odds" by Blue Origin, touched down on the company's landing platform, Jacklyn, in the Atlantic Ocean nearly nine and a half minutes after liftoff. The booster launched NASA's ESCAPADE Mars mission on the NG-2 flight in November. However, the booster reuse on NG-3 was only partial since the stage's biggest component, its BE-4 engines, was new. "With our first refurbished booster we elected to replace all seven engines and test out a few upgrades including a thermal protection system on one of the engine nozzles," Dave Limp, chief executive of Blue Origin, said in an April 13 social media post. "We plan to use the engines we flew for NG-2 on future flights."
The satellite will now be "de-orbited", AST SpaceMobile said in a statement. (They added that "The cost of the satellite is expected to be recovered under the company's insurance policy.")

Thanks to long-time Slashdot reader schwit1 for sharing the news.

After 49 years of space travel, Voyager 1 "is running out of power," reports NPR: The spacecraft runs on a radioisotope thermoelectric generator — a device that converts heat from decaying plutonium into electricity. It carries no solar panels, no rechargeable batteries. Just the slow, steady release of nuclear warmth, which diminishes by about 4 watts each year. After nearly five decades, that decline has become critical.

During a routine maneuver in late February, Voyager 1's power levels fell unexpectedly, bringing the probe dangerously close to triggering an automatic fault-protection shutdown — a self-preservation response that would have forced engineers into a lengthy and risky recovery process. The team needed to act first. On April 17, mission engineers sent a sequence of commands to deactivate the Low-energy Charged Particles experiment, known as the LECP, which is one of Voyager 1's remaining science instruments. The LECP has measured ions, electrons, and cosmic rays originating from both our solar system and the galaxy beyond it, helping scientists map the structure of interstellar space in a way no other instrument could...

Voyager 1 now carries two operational science instruments: one that listens for plasma waves, and one that measures magnetic fields. Engineers believe the latest shutdown could buy the mission roughly another year of breathing room. The team is also developing a more sweeping power conservation plan they informally call "the Big Bang" — a coordinated swap of several powered components all at once, trading older systems for lower-power alternatives. If testing on Voyager 2, planned for May and June 2026, goes well, the same procedure will be attempted on Voyager 1 no sooner than July. If it works, there is even a slim chance the LECP could once more continue to work.

The engineers say they hope to keep at least one instrument operating on each spacecraft into the 2030s. It would leave both still reporting from places no machine has ever gone before.111
Voyager 1 is now 15 billion miles from Earth, the article points out. (Radio signals take 23 hours to arrive...)

Thanks to long-time Slashdot reader fahrbot-bot for sharing the article.

NBC News reports on a 16-person clinical trial of "personalized messenger RNA vaccines" which use the immune system to fight cancer cells. "The goal is not to eliminate existing tumors, but instead to stamp out lingering, undetected cancer cells, and later any new cells that form before they can cause a recurrence." Patients still have surgery to remove tumors. After that, the mRNA vaccines are personalized for each individual using genetic material taken from their unique tumor cells. In the clinical trial, after getting the vaccine, the patients also received chemotherapy, which is standard post-op treatment for operable pancreatic cancer... [The article notes that less than 13% of people diagnosed with pancreatic cancer live for more than five years, making it "one of the deadliest cancers."]

[E]xperts have long believed that people with pancreatic cancer could not generate an immune response against tumors. But after nine doses of the personalized vaccine, [clinical trial participant Donna] Gustafson is one of eight people in the 16-person Phase 1 trial who did just that, producing an army of immune cells called T cells that seek out and destroy tumor cells... [Dr. Vinod Balachandran, a vaccine center director who is leading the trial, said] it was unclear whether the immune response would last and lead to the patients living longer... New data collected during the trial's six-year follow-up period shows that it may. Those findings will be presented Monday at the American Association for Cancer Research's annual meeting in San Diego. Six years after treatment, Gustafson and six others who responded to the treatment are still alive...

More research is still needed. Genentech and BioNTech, the two drugmakers behind the vaccine, have already launched a larger Phase 2 clinical trial... Another team is working on an off-the-shelf vaccine that targets a protein called KRAS that is present in as many as 90% of pancreatic cancers. In a small, early trial, about 85% of the participants mounted an immune response to the protein.

After Artemis II's astronauts returned to earth, "NASA has Artemis III in its sights," reports the Associated Press: In a mission recently added to the docket for next year, Artemis III's yet-to-be -named astronauts will practice docking their Orion capsule with a lunar lander or two in orbit around Earth. Elon Musk's SpaceX and Jeff Bezos' Blue Origin are racing to have their company's lander ready first. Musk's Starship and Bezos' Blue Moon are vying for the all-important Artemis IV moon landing in 2028. Two astronauts will aim for the south polar region, the preferred location for [NASA Administrator Jared] Isaacman's envisioned $20 billion to $30 billion moon base. Vast amounts of ice are almost certainly hidden in permanently shadowed craters there — ice that could provide water and rocket fuel.

The docking mechanism for Artemis III's close-to-home trial run is already at Florida's Kennedy Space Center. The latest model Starship is close to launching on a test flight from South Texas, and a scaled-down version of Blue Moon will attempt a lunar landing later this year.

Slashdot reader smazsyr writes: A new review says we've had fructose wrong for decades. The nine authors, led by Richard Johnson at the University of Colorado Anschutz, argue that fructose "is not just another calorie." It is a signal. It tells the liver to make fat and brace for a famine that never comes. That made sense for a bear fattening up on autumn berries. It makes less sense for a person drinking soda in March.

The review reframes the WHO's sugar guideline, argues ScienceBlog.com, as "less a recommendation about calories and more a warning about a signalling molecule we have been dosing ourselves with, several times a day, for most of a century."

NASA has revived support for the European Space Agency's long-delayed Rosalind Franklin Mars rover mission. According to the space agency, the current plan is to launch via a SpaceX Falcon Heavy no earlier than 2028. Engadget reports: This is a partnership between NASA and the ESA, with the European agency providing the rover, the spacecraft and the lander. The US will provide braking engines for the lander, heater units for the rover's internal systems and, of course, assistance with the actual launch.

The rover will be outfitted with scientific instruments to look for signs of ancient life on the red planet. These include a state-of-the-art mass spectrometer and an organic molecule analyzer, which will come in handy as the vehicle collects samples at the Oxia Planum landing site. The mission has been stuck in development limbo since 2001, with delays caused by budget problems, technical issues, shifting international partners, and geopolitical fallout. After NASA dropped out, Russia stepped in, then was cut loose after invading Ukraine, and now -- despite NASA rejoining in 2024 and fresh political budget threats -- the rover is tentatively back on track for a 2028 launch.

An anonymous reader quotes a report from the Guardian: The critical Atlantic current system appears significantly more likely to collapse than previously thought after new research found that climate models predicting the biggest slowdown are the most realistic. Scientists called the new finding "very concerning" as a collapse would have catastrophic consequences for Europe, Africa and the Americas. The Atlantic meridional overturning circulation (Amoc) is a major part of the global climate system and was already known to be at its weakest for 1,600 years as a result of the climate crisis. Scientists spotted warning signs of a tipping point in 2021 and know that the Amoc has collapsed in the Earth's past.

Climate scientists use dozens of different computer models to assess the future climate. However, for the complex Amoc system, these produce widely varying results, ranging from some that indicate no further slowdown by 2100 to those suggesting a huge deceleration of about 65%, even when carbon emissions from fossil fuel burning are gradually cut to net zero. The research combined real-world ocean observations with the models to determine the most reliable, and this hugely reduced the spread of uncertainty. They found an estimated slowdown of 42% to 58% in 2100, a level almost certain to end in collapse.

The Amoc is a major part of the global climate system and brings sun-warmed tropical water to Europe and the Arctic, where it cools and sinks to form a deep return current. A collapse would shift the tropical rainfall belt on which many millions of people rely to grow their food, plunge western Europe into extreme cold winters and summer droughts, and add 50-100cm to already rising sea levels around the Atlantic. The slowdown has to do with the Arctic's rapidly rising temperatures from global warming. "Warmer water is less dense and therefore sinks into the depths more slowly," explains the Guardian. "This slowing allows more rainfall to accumulate in the salty surface waters, also making it less dense, and further slowing the sinking and forming an Amoc feedback loop."

The new research has been published in the journal Science Advances.

An anonymous reader quotes a report from Ars Technica: On Thursday, OpenAI announced it had developed a large language model specifically trained on common biology workflows. Called GPT-Rosalind after Rosalind Franklin, the model appears to differ from most science-focused models from major tech companies, which have generally taken a more generic approach that works for various fields. In a press briefing, Yunyun Wang, OpenAI's Life Sciences Product Lead, said the system was designed to tackle two major roadblocks faced by current biology researchers. One is the massive datasets created by decades of genome sequencing and protein biochemistry, which can be too much for any one researcher to take in. The second is that biology has many highly specialized subfields, each with its own techniques and jargon. So, for example, a geneticist who finds themselves working on a gene that's active in brain cells might struggle to understand the immense neurobiological literature.

Wang said the company had taken an LLM and trained it on 50 of the most common biological workflows, as well as on how to access the major public databases of biological information. Further training has resulted in a system that can suggest likely biological pathways and prioritize potential drug targets. "We're connecting genotype to phenotype through known pathways and regulatory mechanisms, infer likely structural or functional properties of proteins, and really leveraging this mechanistic understanding," Wang said. To address LLMs' tendencies toward sycophancy and overenthusiasm, OpenAI says it has tuned the model to be more skeptical, so it's more likely to tell you when something is a bad drug target. There was a lot of talk about GPT-Rosalind's "reasoning" and "expert-level" abilities. We were told that the former was defined as being able to work through complex, multi-step processes, while the latter was derived from the model's performance on a handful of benchmarks. Access to GPT-Rosalind is currently limited "due to concerns about the model's potential for harmful outputs if asked to do something like optimize a virus's infectivity," notes Ars. Only U.S.-based organizations can request access at the moment.

An anonymous reader quotes a report from the Guardian: We may appear to have little in common with sperm whales – enormous, ocean-dwelling animals that last shared a common ancestor with humans more than 90 million years ago. But the whales' vocalized communications are remarkably similar to our own, researchers have discovered. Not only do sperm whale have a form of "alphabet" and form vowels within their vocalizations but the structure of these vowels behaves in the same way as human speech, the new study has found.

Sperm whales communicate in a series of short clicks called codas. Analysis of these clicks shows that the whales can differentiate vowels through the short or elongated clicks or through rising or falling tones, using patterns similar to languages such as Mandarin, Latin and Slovenian. The structure of the whales' communication has "close parallels in the phonetics and phonology of human languages, suggesting independent evolution," the paper, published in the Proceedings B journal, states. Sperm whale coda vocalizations are "highly complex and represent one of the closest parallels to human phonology of any analyzed animal communication system," it added.

[...] The new study shows that "sperm whale communication isn't just about patterns of clicks -- it involves multiple interacting layers of structure," said Mauricio Cantor, a behavioral ecologist at the Marine Mammal Institute who was not involved in the research. "With this study, we're starting to see that these signals are organized in ways we didn't fully appreciate before." The latest discovery around sperm whale speech has inched forward the possibility of someday fully understanding the creatures and even communicating with them. Project CETI has set a goal of being able to comprehend 20 different vocalized expressions, relating to actions such as diving and sleeping, within the next five years. A future where we're able to fully understand what the whales are saying and be able to have a conversation with them is "totally within our grasp," said David Gruber, founder and president of Project CETI. "We've already got a lot further than I thought we could. But it will take time, and funding. At the moment we are like a two-year-old, just saying a few words. In a few years' time, maybe we will be more like a five-year-old."