Citing new research, the Associated Press reports that "modest gains in the fight to curb climate change have dialed back the most catastrophic of future heating."

That's the good news. But the same research "also confirmed that there's no chance to limit warming to the international goal set in 2015." Researchers' new list of seven plausible carbon pollution scenarios for the future are pushing aside two staples of climate policy: the extremes on either end. The extremes have become less probable in the past several years because of how we power our world. Carbon dioxide, released from the burning of gas, oil and coal, is chiefly responsible for warming. Increasing use of green energies, like solar, wind and geothermal, which don't emit carbon dioxide, have lowered top end carbon pollution projections. However, because those changes haven't been fast enough, the bottom end projections have risen.

The Paris climate agreement in 2015 set a goal of limiting warming to 1.5 degrees Celsius (2.7 degrees Fahrenheit) since pre-industrial times, or the mid-1800s, giving rise to the mantra "1.5 to stay alive," but now scientists say that even their best case scenario still shoots past that signature temperature mark. On the other end, those same new scenarios no longer include the coal-heavy future that would lead to 4.5 degrees Celsius (8.1 degrees Fahrenheit) of warming by 2100, a scary scenario that many scientific studies used in their future projections.

The new proposed worst case scenario has an end-of-the-century warming of about 3.5 degrees Celsius (6.3 degrees Fahrenheit), a full degree (1.8 degrees Fahrenheit) less than the old scenario, while the updated best case future is a couple tenths of a degree Celsius (0.36 degrees Fahrenheit) warmer than previously theorized, squeezing past the Paris goal, said climate scientist Detlef Van Vuuren of Utrecht University, lead author of a recent study laying out future scenarios. "There is kind of a narrowing of the futures. It cannot be as bad as we thought, but it cannot be as good as we hoped," said Johan Rockström, director of the Potsdam Institute for Climate Impact Research in Germany.

The scenarios include a "middle" one where by the end of the century the world warms 3 degrees Celsius (5.4 degrees Fahrenheit) above pre-industrial times, which is roughly the path society is currently on, scientists said... Because carbon pollution keeps rising globally and stays in the atmosphere for about century, the best case scenario is for warming to shoot past the 1.5 degree mark, peak at 1.7 degrees Celsius (3.1 degrees Fahrenheit) for maybe as long as 70 years, and eventually somehow come back down below 1.5 degrees if a technology can be designed to remove massive amounts of carbon from the air, said nine of the 10 scientists interviewed for this article. The world is warming at a pace of a tenth of a degree Celsius (nearly 0.2 degrees Fahrenheit) every five years, they said.

NASA plans to open competition for the contract to operate JPL for the first time in nearly a century, meaning Caltech's historic role managing the iconic deep-space lab could come to an end when its current agreement expires in 2028. According to JPL, Caltech has managed the lab since the its inception in the 1930s, and has done so for NASA since the agency was established in 1958. Space.com reports: According to the JPL statement, Caltech has been preparing for this possible transition since last summer, so the news "comes as no surprise." But the potential change is part of a larger shakeup for the agency. Earlier this morning, NASA announced a major reorganization, which is separate from the JPL news. "To support the agency's ambitious short- and long-term goals, NASA is taking action to increase specialization at centers and integrate mission directorates, elevating delivery of technically excellent work," the agency said in a statement today.

JPL is NASA's lead center for the robotic exploration of Mars and other deep-space locales. The agency has worked with JPL through Caltech as a manager for nearly 70 years. Though JPL still counts as one of NASA's field centers, it's run as a contracted FFRDC (federally funded research and development center). This status has allowed the lab to function slightly differently than other NASA centers; it has a unique sort of independence, though NASA has always had significant oversight of the lab. "As an FFRDC, JPL operates under a special contractual and governance framework designed to ensure that its work is performed in the public interest and aligned with national priorities," NASA has stated. "The FFRDC model enables NASA to retain access to this depth of capability while maintaining a clear separation between government decision-making authority and contractor execution responsibilities."

Opening up the competition for institutions beyond Caltech to operate JPL could mean significant changes for everything from day-to-day mission management to big NASA science programs. Until now, JPL and Caltech have been heavily intertwined, with mission personnel, scientists, leadership, and others working closely "across the pond" between JPL and Caltech. JPL mission and program meetings often include Caltech employees and sometimes even take place on its Pasadena campus.

SpaceX's upgraded Starship V3 launched today from Starbase, Texas, for the first time, successfully deploying 22 dummy Starlink satellites and completing a planned fiery splashdown in the Indian Ocean. Reuters reports: The towering vehicle, consisting of the upper-stage Starship astronaut vessel stacked atop a Super Heavy booster rocket, blasted off at about 5:30 p.m. CT on Friday (2230 GMT) from SpaceX facilities in Starbase, Texas, on the Gulf of Mexico near Brownsville. A live SpaceX webcast of the liftoff showed the rocketship, more than 40 stories tall, climbing from the launch tower as the Super Heavy's cluster of Raptor engines thundered to life in a ball of flames and billowing clouds of vapor and exhaust. The test ended about an hour later when the Starship vehicle made it through a blazing re-entry through Earth's atmosphere and splashed down into the Indian Ocean, nose up as planned, as SpaceX employees who gathered to watch a live webcast of the flight cheered. The lower-stage Super Heavy came down separately in the Gulf of Mexico about six minutes after blast-off.

The launch marked SpaceX's 12th Starship test flight since 2023 and the first ever for the V3 iteration of both the cruise vessel and its Super Heavy booster, as well as the first blast-off from a new launch pad designed for the more powerful rocket. During its suborbital cruise phase, Starship successfully released its payload of 20 mock Starlink satellites one by one, plus two actual modified satellites that scanned the spacecraft's heat shield and transmitted data back to operators on the ground during the vehicle's descent. Starship made it to its cruise phase despite the loss of one of its six upper-stage engines, and mission controllers opted not to attempt an inflight re-ignition of the engines before re-entry. But the vehicle did execute a return-landing burn at the very end of its flight, along with several aerodynamic maneuvers deliberately intended to place the spacecraft under maximum stress, and Starship completed those moves intact for its controlled final descent. You can watch a recorded livestream of the launch on YouTube.

A new Oxford Longevity Project report argues that individuals bear at least 80% of the responsibility for ill health in old age. "The report (PDF), launched at the Smart Ageing Summit in Oxford last week, argues that individuals have far greater control over their longevity than is commonly understood," reports The Guardian. "The authors call on the government to take legislative action on alcohol comparable to restrictions on smoking." From the report: Living Longer, Better -- the Oxford Longevity Project's first Age-less report -- was co-authored by an interdisciplinary panel of UK-based experts in medicine, physiology, ageing and education policy. It was sponsored by Oxford Healthspan. The report's authors, Sir Christopher Ball, Sir Muir Gray, Dr Paul Ch'en, Leslie Kenny and Prof Denis Noble, present the figure of 80% as a conservative estimate. [...] The claim, however, has been described as simplistic and said to neglect wider arguments about whether people are genuinely in control of individual choices when it comes to issues including poverty, pollution and healthcare access.

[...] Ball, however, pointed to research including the Landmark Twins Study, where researchers concluded at least 75% of human lifespan is determined by environmental and modifiable lifestyle factors. He also cited large-scale analysis led by Oxford Population Health using data from nearly 500,000 UK Biobank participants which found that environmental exposures and habits carry far greater weight in premature death and biological ageing than inherited genetics. The report's recommendations include avoiding processed foods, abstaining entirely from alcohol, prioritising sleep, not eating after 6.30pm, and cultivating what it calls "a not-meat mindset." On alcohol, it takes a position more forthright than current government guidance. "Alcohol is toxic, don't drink it," said Ball. "The report bravely says so -- whereas the government is afraid to tell the public the truth."

An anonymous reader quotes a report from TechCrunch: OpenAI claims its new reasoning model has produced an original mathematical proof disproving a famous unsolved conjecture in geometry, which was first posed by Paul Erdos in 1946. If this sounds familiar to you, it's because this isn't the first time OpenAI has made such a bold claim. Seven months ago, the AI giant's former VP Kevin Weil posted on X: "GPT-5 found solutions to 10 (!) previously unsolved Erds problems and made progress on 11 others."

It turns out, GPT-5 didn't actually solve those problems; it just found solutions that already existed in the literature. Taunts from rivals like Yann LeCun and Google DeepMind CEO Demis Hassabis followed, and Weil promptly took down his premature post. Today, at least, it seems OpenAI didn't make the same mistake twice. Alongside the announcement, the company published companion remarks (PDF) in support of the disproof from mathematicians like Noga Alon, Melanie Wood, and Thomas Bloom, who maintains the Erdos Problems website, and previously called Weil's post "a dramatic misrepresentation."

[...] The proof, per OpenAI, came from a new general-purpose reasoning model, not a system specifically designed to solve math problems or even this problem in particular. OpenAI says this is significant because it means AI systems are now more capable of holding together long, difficult chains of reasoning and connecting ideas across fields in ways researchers may not have previously explored. That has implications for biology, physics, engineering, and medicine.

NASA Administrator Jared Isaacman says he expects China to fly taikonauts around the moon in 2027, "ratcheting up perceptions of a space race between China and the United States," reports SpaceNews. He is using that prospect to argue for a revamped Artemis strategy and an accelerated path toward a U.S. lunar return. From the report: "The next time the world tunes in to watch astronauts fly around the moon, which will likely be sometime in 2027, they will be taikonauts, and America will no longer be the exclusive power to send humans into the lunar environment," he said. While Isaacman has frequently discussed a race with China to be the next to land humans on the moon, this was one of the first times he predicted a 2027 Chinese crewed circumlunar mission. He repeated the comments later in the day at an industry reception.

China has not publicly announced plans for such a mission, which, as Isaacman described it, would likely be similar to NASA's Artemis 2 mission in April. There have been rumors of a mission along those lines, though, and an expectation of a roadmap of missions leading to a Chinese crewed landing by the end of the decade. So far, all the crewed missions to fly around, orbit or land on the moon have been flown by NASA: nine Apollo missions from 1968 to 1972 and Artemis 2. All the astronauts on those missions have been Americans except for Canadian Space Agency astronaut Jeremy Hansen on Artemis 2.

Isaacman has used the threat that China could land astronauts on the moon before NASA returns there as a rationale for revamping the Artemis lunar exploration program. In February, he announced that Artemis 3, which was to be a lunar landing attempt in 2028, will instead be a test flight in low Earth orbit in 2027, followed by a landing on Artemis 4 in 2028. In March, he changed other elements of Artemis at the agency's Ignition event, including effectively canceling the lunar Gateway to focus resources instead on a lunar base, while calling for a much higher cadence of robotic lander missions.

Colossal Biosciences says it has grown chickens inside 3D-printed artificial eggshells. "The company says the egg technology could help conserve at-risk bird species," reports MIT Technology. "It could also play a role in a project to re-create the extinct giant moa, a flightless 12-foot-tall bird that once lived in New Zealand and laid four-liter eggs, larger than those of any living bird." From the report: The biotech company today claimed it has developed a "fully artificial egg" as part of its effort to resurrect extinct avian species, including birds like the dodo and the giant moa. But "artificial eggshell" would probably be a better description for the invention. It's an oval-shaped printed lattice, coated inside with a special silicone-based membrane that lets in oxygen, just as a real eggshell does. To generate birds, Colossal took recently laid chicken eggs and carefully poured their contents into the artificial shells, where they continued growing. A window on top lets researchers peek inside. "To see them all moving around in their artificial eggs was absolutely mind blowing," says Andrew Pask, the company's chief biology officer. "You really feel you can grow life outside of the womb."

[...] The work on the artificial eggshell was carried out in Dallas by Colossal's exogenous development team, or Exo Dev. That group is also trying to develop artificial wombs for mammals, starting with marsupials. "We're looking at every single facet of what's happening during a mammalian pregnancy to unpack exactly how we then go about recapitulating that," says Pask. For that team, an artificial eggshell is a relatively quick and easy technical win. That's because chickens are already an example of ex utero development. After an egg is laid, a small embryo sitting on top of the yolk starts growing, drawing nutrients from the yolk, the white, and even the shell, which provides calcium. (Colossal says it has to add ground-up calcium to the artificial eggs.)

In order to create a moa, Colossal will have to genetically alter another type of bird, changing potentially thousands of DNA letters. But so far, chickens are the only bird species that can be genetically engineered. And that's via a tricky process of editing stem cells that produce egg and sperm. Scientists have to add or delete DNA letters from these cells and then inject them back into an egg. The resulting bird will carry the genetic changes in its gonads -- and then be able to pass them on. Pask says Colossal's idea is that it could modify avian stem cells enough to produce moa-like sperm or eggs. But then you might have the odd situation of a chicken laying an egg with a moa embryo inside it. "You would have chickens making moa egg and moa sperm. But it's still a chicken egg," he says.

Astronomers using the James Webb Space Telescope have identified an ultra-faint galaxy seen just 800 million years after the Big Bang. The galaxy contains almost no heavy elements, shows signs of intense early stellar radiation, and could offer a rare glimpse into the first stages of galaxy formation. Phys.org reports: In a paper published in the journal Nature, a team of scientists led by Kimihiko Nakajima, an astronomer at Kanazawa University, Japan, describes how they used the telescope to study a part of the deep universe and discovered a faint galaxy called LAP1-B. "LAP1-B establishes a 'fossil in the making,' a direct high-redshift progenitor of the ancient ultra-faint dwarf galaxies observed in the local universe," they wrote. Because the galaxy is so small and distant, it would normally be impossible to see. However, it was spotted due to a phenomenon known as gravitational lensing, in which a massive cluster of closer galaxies acts like a giant magnifying glass, boosting the light from LAP1-B by 100 times.

The scientists realized that most of the light from the galaxy wasn't coming from the stars, but from glowing clouds of gas. They analyzed this light by splitting it into a spectrum and studying the emission lines, which revealed the chemical composition of the gas. They found that the galaxy contains almost no heavy elements, and its oxygen abundance is about 240 times lower than the sun's, making it one of the most primitive star-forming galaxies ever observed. The emission lines also revealed intense ionizing radiation, which is what scientists expect to see from the first generation of stars.

The team also measured an elevated carbon-to-oxygen ratio. This matches the predicted chemical signature for the first star explosions in history from Population III stars, the first stars to exist in the universe. The stars we see today are Population I stars, which formed later and contain more heavy elements. Another fascinating finding is that, after measuring the gas's motion and speed, the researchers concluded that the galaxy is held together by a massive cloud of invisible dark matter.

An anonymous reader quotes a report from the New York Times: The World Health Organization declared on Saturday that the spread of the Ebola virus in the Democratic Republic of Congo and Uganda was a global health emergency. The announcement was made a day after Africa's leading public health authority reported that an outbreak in a province in the northeast of the country was linked to dozens of suspected deaths. By Saturday, cases had also been confirmed in Kampala, the capital of Uganda, the W.H.O. said.

In Congo's Ituri province, where the outbreak was first identified, 246 suspected cases and 80 deaths attributed to the virus had been reported, although only eight cases had been definitively linked to the virus through laboratory testing. There is no approved vaccine and no therapeutics for the Bundibugyo species of Ebola behind the outbreak, according to the W.H.O. The scale of the outbreak could be far larger than has been detected and reported, the W.H.O. said in declaring a "public health emergency of international concern." It added that there were "significant uncertainties" about the precise number of people infected and the "geographic spread."

The W.H.O.'s declaration signals a public health risk requiring a coordinated international response, and is intended to prompt member countries to prepare for the virus to spread and to share vaccines, treatments and other resources needed to contain the outbreak. [...] The risk of the outbreak spreading is exacerbated by a humanitarian crisis, high population mobility and a large network of informal health care facilities in the area, the agency said. Containing an Ebola outbreak depends on the speed and scale of the public health response. The virus is transmitted through direct contact with the bodily fluids of an infected person, putting family members and caregivers at particular risk. Tracing people who may have come into contact with sufferers, isolating and treating victims promptly and safely, and burying the dead properly are all viewed as critical steps.

"We may have accidentally detected dark matter back in 2019," writes ScienceAlert.

"What if instead of trying to see dark matter, scientists attempted to hear it instead?" asks Space.com: New research suggests dark matter could leave a tiny but discernible imprint in the cacophony of ripples in spacetime called "gravitational waves" that ring through the cosmos when two black holes slam together and merge... Fortunately, when it comes to detecting gravitational waves from colliding black holes, humanity's instruments, such as LIGO (Laser Interferometer Gravitational-Wave Observatory), are getting more and more sensitive all the time...

Vicente and colleagues searched through data gathered by LIGO and its fellow gravitational wave detectors, KAGRA (Kamioka Gravitational Wave Detector) and Virgo, focusing on 28 of the clearest signals from merging black holes. Of these, 27 appeared to have come from mergers that occurred in the relative vacuum of space. One signal, however, GW190728, first heard on July 19, 2019, and the result of merging binary black holes with a combined mass of 20 times that of the sun and located an estimated 8 billion light-years away, seemed to carry the telltale trace of this merger occurring in a region of dense, "buttery" dark matter.

The team behind this research is quick to point out that this can't be considered a positive detection of dark matter, but does say it gives us a hint at what to look for and thus where to direct follow-up investigations... "We know that dark matter is around us. It just has to be dense enough for us to see its effects," said team leader Josu Aurrekoetxea, of the Massachusetts Institute of Technology (MIT) Department of Physics. "Black holes provide a mechanism to enhance this density, which we can now search for by analyzing the gravitational waves emitted when they merge."
They published their results this week in the journal Physical Review Letters.

Test scores "are lower than they were a decade ago in school districts across the U.S.," reports Times magazine, citing new data released Wednesday by Stanford researchers. "Reading scores were down roughly 0.6 grades in 2025 compared to 2015, and math scores were down about 0.4 grades. This means that students were 60% of one school year behind where their peers were in reading a decade earlier and 40% of one school year behind in math."

But Stanford's announcement notes that America's schools "were in a 'learning recession' for seven years before the COVID-19 pandemic, with student test scores in math and reading on a steady decline since 2013." This reversal ended two decades of progress, according to Sean Reardon, the Professor of Poverty and Inequality at Stanford Graduate School of Education, whose data forms the backbone of the new research... The study reframes the narrative of pandemic-era learning loss, arguing that the crisis of the last few years was an acceleration of a problem that was already underway. "The pandemic was the mudslide that followed seven years of erosion in student achievement," said Professor Tom Kane, faculty director of the Center for Education Policy Research at Harvard University, and a lead author of the report...

The study found that the slowdown in learning coincided with two major shifts in American childhood and education policy: the widespread dismantling of test-based accountability systems that defined the No Child Left Behind era and the rise of social media use among young people. Reading scores, in particular, suffered consistently, with the average annual loss in the years just before the pandemic being just as large as the loss during it... Today, 8th-grade reading scores on national assessments are at their lowest point since 1990.

Compounding the problem, chronic student absenteeism remains a major obstacle to improving learning. Though down from its pandemic peak, 23 percent of students were chronically absent in the 2024-25 school year, far above the pre-pandemic rate of 15 percent.
More context from Time magazine: Reading scores were down roughly 0.6 grades in 2025 compared to 2015, and math scores were down about 0.4 grades. This means that students were 60% of one school year behind where their peers were in reading a decade earlier and 40% of one school year behind in math...

"The decline started around the time that social media's use among teens was exploding, and this was also occurring in a number of other countries," says Thomas Kane, one of the authors of the Educational Scorecard report and a professor at Harvard University... [H]e maintains that it is at the core of the decline in reading achievement. He points out that social media use was shown to be heaviest among the lowest achieving students.
"Some states and school districts are making progress," notes the Associated Press, "largely by shifting toward phonics-based instruction and providing extra support for struggling readers."

And "The picture is also brighter in math. Almost every state in the analysis saw improvements in math test scores from 2022 to 2025."

Are statistical programmers coalescing around a handful of popular languages? That's the question asked by the CEO of software assessment site TIOBE, which every month estimates the popularity of programming languages based on their frequency in search results: This month, the programming language R matched its all-time high by reaching position #8 in the TIOBE index once again. This is not a coincidence. The statistical programming language market is clearly undergoing a major consolidation. The biggest winners are Python and R, while many long-established alternatives continue to lose momentum. The era in which the statistical computing landscape was fragmented across many niche languages and platforms appears to be coming to an end.

Several established players are steadily declining:

— MATLAB is close to dropping out of the TIOBE top 20.

— SAS is about to leave the top 30 for the first time since the TIOBE index began.

— Wolfram/Mathematica remains well below its historical peak and is losing further ground.

— SPSS dropped out of the top 100 last month....


Elsewhere in the index, Java and C++ swapped positions this month. Java gained momentum following the successful release of Java 26. Another notable riser is Zig, which is approaching the TIOBE top 30 for the first time. Zig's growing popularity appears to be driven by its rare combination of low-level performance, straightforward tooling, and relative ease of use compared to traditional systems programming languages.
Their estimate for the most popular programming languages in May:

1. Python
2. C
3. Java
4. C++
5. C#
6. JavaScript
7. Visual Basic
8. R
9. SQL
10. Delphi/Object Pascal

The five next most popular languages on their rankings are Fortran, Scratch, Perl, PHP, and then Rust at #15. Rust is up for positions from May of 2025 — while Go has dropped to #16, seven ranks lower than its May 2025 position of #7.

SpaceX has detailed major Starship V3 upgrades ahead of a launch targeted as early as May 19. The changes are meant to move Starship closer to its core goals: rapid reuse, Starlink deployment, orbital refueling, and eventually Moon and Mars missions. Longtime Slashdot reader schwit1 shares a report from Teslarati: Here is an explicit, broken-down list of the key changes, first starting with the changes to Super Heavy V3:

- Grid Fin Redesign: Reduced from four fins to three. Each fin is now 50% larger and stronger, repositioned for better catching and lifting performance. Fins are lowered on the booster to reduce heat exposure during hot staging, with hardware moved inside the fuel tank for protection.
- Integrated Hot Staging: Eliminates the old disposable interstage shield. The booster dome is now directly exposed to upper-stage engine ignition, protected by tank pressure and steel shielding. Interstage actuators retract after separation.
- New Fuel Transfer System: Massive redesign of the fuel transfer tube -- roughly the size of a Falcon 9 first stage -- enables simultaneous startup of all 33 Raptors for faster, more reliable flip maneuvers.
- Engine Bay/Thermal Protection: Engine shrouds removed entirely; new shielding added between engines. Propulsion and avionics are more tightly integrated. CO? fire suppression system deleted for a simpler, lighter aft section.
- Propellant Loading Improvements: Switched from one quick disconnect to two separate systems for added redundancy and reduced pad complexity.

Next, we have the changes to Starship V3:

- Completely Redesigned Propulsion System: Clean-sheet redesign supports new Raptor startup, larger propellant volume, and an improved reaction control system while reducing trapped or leaked propellant risk.
- Aft Section Simplification: Fluid and electrical systems rerouted; engine shrouds and large aft cavity deleted.
- Flap Actuation Upgrade: Changed from two actuators per flap to one actuator with three motors for better redundancy, mass efficiency, and lower cost.
- Faster Starlink Deployment: Upgraded PEZ dispenser enables quicker satellite release.
- Long-Duration Spaceflight Capability: New systems for long orbital coasts, orbital refueling, cryogenic fluid management, vacuum-insulated header tanks, and high-voltage cryogenic recirculation.
- Ship-to-Ship Docking + Refueling: Four docking drogues and dedicated propellant transfer connections added to support in-space refueling architecture.
- Avionics Upgrades: 60 custom avionics units with integrated batteries, inverters, and high-voltage systems (9 MW peak power). New multi-sensor navigation for precision autonomous flight. RF sensors measure propellant in microgravity. ~50 onboard camera views and 480 Mbps Starlink connectivity for low-latency communications. "Believe it or not, there's more," writes schwit1. "Two years ago, the biggest and most powerful rocket ever flown was Starship V1. Last year, it was Starship V2. V3 is about to become the biggest and most powerful rocket ever flown -- but don't worry, the company already has plans for V4."

A trio of preprint papers suggests the universe may not be perfectly uniform on the largest scales, finding tentative 2-to-4-sigma deviations from a core assumption of standard cosmology known as FLRW geometry. Live Science reports: The work combines observations of distant exploding stars and large-scale galaxy surveys to probe whether the universe truly follows a nearly 100-year-old mathematical framework known as Friedmann-Lemaitre-Robertson-Walker (FLRW) cosmology. The analyses revealed mild-but-intriguing deviations from the predictions of the standard model. "We saw a surprising violation of an FLRW curvature consistency test, hinting at new physics beyond the standard model," study co-author Asta Heinesen, a physicist at the Niels Bohr Institute in Copenhagen and Queen Mary University in London, told Live Science via email, referring to the assumption that the space's curvature is the same everywhere. "This could potentially be due to various effects, but more research is needed to address the cause of the FLRW violation that we see empirically."

[...] The analyses revealed small but potentially important departures from the predictions of standard FLRW cosmology. Depending on the dataset and analysis method, the discrepancy reached a statistical significance of about 2 to 4 sigma. In physics, sigma measures how likely a result is to arise purely by chance; a 5-sigma result is typically required before scientists claim a discovery, so the new findings remain tentative. Still, the results suggest that something unexpected may be affecting the geometry or expansion of the universe. "The main finding is that you can directly measure Dyer-Roeder and backreaction effects from available cosmological data, and clearly distinguish these effects from other alterations of the standard cosmological model, such as evolving dark energy and modified gravity theories," Heinesen said. "This was previously not possible in such a direct way, and this is what I think is the breakthrough in our work."

"If these indicated deviations from an FLRW geometry are real, it would signify that most of the cosmological solutions considered for solving the cosmological tensions -- evolving or interacting dark energy, new types of matter or energy, modified gravity and related ideas within the FLRW framework -- are ruled out," the researchers wrote. The next step will involve applying the new theoretical framework to larger and more precise datasets. "It is to apply our theoretical results to data to test the standard model and to produce constraints on the Dyer-Roeder and backreaction effects," Heinesen said.

fjo3 shares a report from Phys.org: Ever felt like mosquitoes bite you while ignoring everyone else? Scientists are now making progress in deciphering the complex chemical cocktail that makes particular people more enticing to these disease-spreading bloodsuckers. "It's not a misconception -- mosquitoes are attracted to some people more than others," Frederic Simard of France's Institute of Research for Development told AFP. "But we are not all magnets all the time," the medical entomologist added.

A range of sensory cues can cause mosquitoes to pick one human over another -- mainly the smell and heat our bodies give off, and the carbon dioxide we exhale. Female mosquitoes -- which are the only ones that bite -- detect these signals with finely tuned receptors, then choose their target accordingly. "We have known for over 100 years that mosquitoes are attracted by the carbon dioxide that we exhale -- this is the first signal that triggers their behavior" when they are dozens of meters away, Swedish scientist Rickard Ignell told AFP. Within around 10 meters, "mosquitoes will start detecting our odor, and in combination with carbon dioxide," this attracts them even more, said the senior author of a recent study on the subject. As they get closer, body temperature and humidity make particular humans even more enticing.

[...] For Ignell's recent study, the researchers released Aedes aegypti mosquitoes -- known for spreading yellow fever and dengue -- on 42 women in a lab, to see which ones they preferred. "We have shown that mosquitoes use a blend of odorous compounds (we identified 27 that the mosquitoes will detect, out of the possible 1,000) for their attraction to us," Ignell said. The woman the mosquitoes most liked to bite -- which included pregnant women in their second trimester -- produced a large amount of a particular compound made by a breakdown of the skin oil sebum. That even a small increase of this compound -- called "1-octen-3-ol", or mushroom alcohol -- made a difference came as a surprise, Ignell emphasized.