Latest news with #Luque
Yahoo
25-05-2025
- Science
- Yahoo
Scientists question possible signs of life on exoplanet K2-18b in new study: 'We never saw more than insignificant hints'
When you buy through links on our articles, Future and its syndication partners may earn a commission. In 2023, scientists from Cambridge University reported what appeared to be very exciting news. NASA's James Webb Space Telescope, they said, had detected signs of a liquid water ocean — and possibly life — on the exoplanet K2-18b, a temperate sub-Neptune world located about 124 light-years away from Earth. Then, earlier this year, the same team announced what they called even stronger evidence for those potential signs of alien life. The signs were rooted in a tentative detection of dimethyl sulfide (DMS) — a molecule produced on Earth solely by marine life — and/or its close chemical relative DMDS, which is also a potential biosignature, in the atmosphere of the exoplanet. This finding, along with the possibility that K2-18b is a "Hycean world" with a liquid water ocean, sparked significant interest about its potential to support life. However, these results have sparked intense debate among astronomers. While recognizing this finding would be a groundbreaking achievement and a major testament to the James Webb Space Telescope's (JWST) capabilities if true, many scientists remain skeptical, questioning both the reliability of the detected DMS signature as well as whether DMS itself is a dependable sign of life in the first place. As such, many independent teams have been conducting follow-up studies about the original claims — and a newly published one only adds to the debate, suggesting the Cambridge scientists' DMS detection wasn't significant enough to warrant the publicity it received. "Among the physical sciences, astronomy enjoys a privileged position," Rafael Luque, a post doctoral researcher at the University of Chicago, told "It is more frequently covered in the media thanks to its visual appeal and the big philosophical and universal questions it addresses. It was therefore expected that — even if tentative — the detection of a potential biomarker in the atmosphere of an exoplanet would have extensive coverage." Luque and his colleagues, including fellow postdoctoral researchers Caroline Piaulet-Ghorayeb and Michael Zhang, remain unconvinced that what astronomers observed on K2-18b was in fact a credible signature indicating life. In a recent arxiv preprint — which is yet to be peer-reviewed — their team re-examined the validity of the original evidence. "This is how science works: evidence and counterevidence go hand in hand,' he stated. When scientists study data from different instruments separately, they might end up with conflicting results — it's like finding two different "stories" about a subject that don't match. "This is, in fact, what happened in the original team's papers," Zhang told "They inferred a much higher temperature from their MIRI (mid-infrared) data than from their NIRISS and NIRSpec (near-infrared) data. Fitting all the data with the same model ensures that we're not telling contradictory stories about the same planet." Thus, the team conducted a joint analysis of K2-18b using data from all three of the JWST's key instruments — the Near Infrared Imager and Slitless Spectrograph (NIRISS) and the Near Infrared Spectrograph (NIRSpec), which capture near-infrared light, and the Mid-Infrared Instrument (MIRI), which detects longer mid-infrared wavelengths. The goal was to ensure a consistent, planet-wide interpretation of K2-18b's spectrum that the team felt the original studies both lacked. "We reanalyzed the same JWST data used in the study published earlier this year, but in combination with other JWST observations of the same planet published […] two years ago," Piaulet-Ghorayeb told "We found that the stronger signal claimed in the 2025 observations is much weaker when all the data are combined." These signals may appear weaker when all data is combined because the initial "strong" detection may have been overestimated, the team says, due to being based on a limited initial data set. Combining data from multiple sources lets scientists cross-check and verify the strength — and validity — of a particular signal. "Different data reduction methods and retrieval codes always give slightly different results, so it is important to try multiple methods to see how robust the results are," explained Piaulet-Ghorayeb. "We never saw more than insignificant hints of either DMS or DMDS, and even these hints were not present in all data reductions." "Importantly, we showed that when testing a wider range of molecules that we expect to be produced abiotically in the atmosphere, the same observed spectral features can be reproduced without the need for DMS or DMDS," she continued. Molecules in an exoplanet's atmosphere are typically detected through spectral analysis, which identifies unique "chemical fingerprints" based on how the planet's atmosphere absorbs specific wavelengths of starlight as it passes — or transits — in front of its host star. This absorption leaves distinct patterns in the light spectrum that reveal the presence of different molecules. "Each molecule's signature is unique, but different molecules can have some features that fall in similar places because of their close molecular structures," explained Piaulet-Ghorayeb. The difference between DMS and ethane — a common molecule in exoplanet atmospheres — is just one sulfur atom, and current spectrometers, including those on the JWST, have impressive sensitivity, but still face limits. The distance to exoplanets, the faintness of signals, and the complexity of atmospheres mean distinguishing between molecules that differ by just one atom is extremely challenging. "It is widely recognized as a huge problem for biomarker detection, though not an insurmountable one, because different molecules do have subtly different absorption features," said Piaulet-Ghorayeb. "Until we can separate these signals more clearly, we have to be especially careful not to misinterpret them as signs of life." Beyond technical limitations, another source of skepticism is how the data has been interpreted statistically. Luque points out that the 2023 study described the detection of DMS as "tentative," reflecting the preliminary nature of the finding. However, the most recent 2025 paper reported that the detection of DMS and/or DMDS reached 3-sigma significance — a level that, while below the 5-sigma threshold required for a confirmed discovery, is generally considered moderate statistical evidence. "Surprisingly, this latest work was used to double down on the claim for DMS and even more complex molecules to be present. The detection, however, is not statistically significant nor robust, as we show in our work. Despite these uncertainties, the team is worried that media coverage has continued to spotlight bold claims about DMS and other molecules. "The [JWST] telescope is incredibly powerful, but the signals we're detecting are very small. As a community, we have to make sure that any claims we make about a planet's composition are robust to the choices made when processing the data from the telescope," said Piaulet-Ghorayeb. Related Stories: — Doubts over signs of alien life on exoplanet K2-18b are rising: 'This is evidence of the scientific process at work' — Does exoplanet K2-18b host alien life or not? Here's why the debate continues — The pursuit of truths: A letter on the boy who cried aliens (op-ed) "Researchers have the responsibility to double-check and verify, but the media is also responsible for duly reporting these follow-up works to the general public," added Luque. "Even if they have less catchy titles." "As Carl Sagan once said, 'extraordinary claims require extraordinary evidence,'" said Luque. "That threshold was not met by how the results were disseminated to the general public." Whether we'll ever get a clear answer about life on K2-18 b is uncertain — not just because of technological limits, but because the case for follow-ups with the JWST may simply not be strong enough. "JWST is continuing to observe K2-18b, and even though the new observations won't have the ability to detect life, we will soon find out more about the planet's atmosphere and interior," Zhang said.
Yahoo
24-05-2025
- Sport
- Yahoo
FIFA president cites 'discussions' for Ronaldo to play in Club World Cup
FIFA President Gianni Infantino addresses the FIFA 75th Congress at the Conmebol Convention Center in Luque, Paraguay, Thursday, May 15, 2025. (AP Photo/Fernando Calistro) FILE - Portugal's Cristiano Ronaldo gestures to the crowd after winning the UEFA Nations League soccer match between Portugal and Denmark, at the Jose Alvalade Stadium in Lisbon, March 23, 2025. (AP Photo/Armando Franca, File) FILE - Portugal's Cristiano Ronaldo gestures to the crowd after winning the UEFA Nations League soccer match between Portugal and Denmark, at the Jose Alvalade Stadium in Lisbon, March 23, 2025. (AP Photo/Armando Franca, File) FIFA President Gianni Infantino addresses the FIFA 75th Congress at the Conmebol Convention Center in Luque, Paraguay, Thursday, May 15, 2025. (AP Photo/Fernando Calistro) FILE - Portugal's Cristiano Ronaldo gestures to the crowd after winning the UEFA Nations League soccer match between Portugal and Denmark, at the Jose Alvalade Stadium in Lisbon, March 23, 2025. (AP Photo/Armando Franca, File) GENEVA (AP) — FIFA president Gianni Infantino says Cristiano Ronaldo might play in the Club World Cup because of a unique transfer window. Ronaldo's Saudi Arabian club Al Nassr also did not qualify for the tournament, but Infantino suggested that the Portugal star could switch to one of the 32 teams playing in the competition in the United States starting next month. Advertisement 'Cristiano Ronaldo might play in the Club World Cup,' Infantino told online streamer IShowSpeed. 'There are discussions with some clubs, so if any club is watching and is interested in hiring Ronaldo for the Club World Cup, who knows. Still a few weeks time, will be fun.' FIFA confirmed Wednesday that last-minute transfer signings are open to all teams going to tournament, which fueled more speculation that one of them will try to sign the 40-year-old Ronaldo on a short-term deal, potentially a loan. Such a move would be unprecedented in modern soccer though could appeal to FIFA by boosting the profile and ticket sales of an inaugural tournament being played in 11 U.S. cities. It has been unclear if many fans will travel to the U.S. for the 63-game tournament. A transfer for Ronaldo also would reunite him and Lionel Messi in the same competition for the first time since the 2022 World Cup in Qatar. Advertisement Last October, FIFA invited Messi's Inter Miami to enter the tournament in the slot that was expected to be reserved for the host nation's champion. Inter Miami led the regular season standings but was then eliminated in the MLS Cup playoffs. Speculative reports have linked Ronaldo to the one Saudi club that qualified, Al Hilal, the Brazilian club Palmeiras and Wydad of Morocco, even though that club is currently banned by FIFA from registering new signings. Transfers can be made from June 1-10 and again June 27-July 3 according to exceptional rules FIFA approved in October. 'The objective is to encourage clubs and players whose contracts are expiring to find an appropriate solution to facilitate the players' participation,' FIFA said in Wednesday's statement. ___ AP soccer:
USA Today
20-05-2025
- Sport
- USA Today
Vicente Luque seeks UFC 316 finish Kevin Holland to prove he's 'hungry for that title'
Vicente Luque seeks UFC 316 finish Kevin Holland to prove he's 'hungry for that title' Vicente Luque thinks he's now well past the brain bleed that threatened his career and is ready to show he's back to full form against Kevin Holland at UFC 316. After a more than yearlong hiatus from competition that end in mid-2023, Luque (23-10-1 MMA, 16-6 UFC) has won two of three fights since his comeback. His most recent performance saw him choke out Themba Gorimbo in 52 seconds at UFC 310 in December, setting him up for the June 7 showdown with fan favorite Holland at Prudential Center in Newark, N.J. (ESPN+ pay-per-view, ESPN, ESPN+). Although neither men occupy a top 15 spot in the UFC welterweight rankings, Luque knows the value Holland carries with his name, and he sees this matchup as a key stepping stone in where he needs to be. "It's one of the fights to get me back to the top," Luque told MMA Junkie Radio. "That's what I'm looking for. I want to get back into that mix in the top five. That's the goal for this year, and I think a fight against Holland – it's not easy to get a ranked opponent right now, and I don't want to wait. I've been waiting for a long time and I think that Holland is that kind of name who has been in the rankings in middleweight and welterweight. "He's a guy that everyone is backing and supporting and I think it's a fight that brings the hype, and it's win, if I go out there and pick up a good win against him, I think that sets me up for a great fight after that and moves me up the rankings. That's my goal to get back to that top five and get back to the title picture." Luque thinks the matchup with Holland is one that will bring out his most violent side. He already has the second-most finishes in UFC welterweight history with 14, and can tie Matt Brown's all-time record of 15 if he puts Holland away inside the distance. That is something Luque will be pushing hard for, and when it happen, he thinks he will be back in the rankings and start to gain traction as a title contender that he had earlier in his career. "He's not trying to stall, he's not trying to have a safe fight. That's what I like. That's what brings the best out of me. … My own game is I can knock you out, I can submit you. I'm a complete MMA fighter and more than anything, I'm always going for that finish. It's a style that really matches well." "We have all the ingredients to make a Fight of the Night, a Fight of the Year. To go out there and do what I do and show the UFC and everybody that I'm still hungry for that title. I'm climbing up. I'm just 33 years old. I feel like I'm still just getting better. That's what I'm going to show that night."
BreakingNews.ie
06-05-2025
- Health
- BreakingNews.ie
Maradona requested alcohol and ‘tore out his own IVs' in days after surgery
The director of the clinic where Diego Maradona had surgery two weeks before his death testified that the Argentine football star requested alcohol during the post-operative period and was difficult to deal with – which made his subsequent recovery in home care inadvisable. Pablo Dimitroff, medical director of the Olivos Clinic, said that neurosurgeon Leopoldo Luque – one of the seven health professionals on trial – requested 'a place' so the former player could undergo surgery in early November 2020. Advertisement Maradona had surgery for a haematoma that formed between his skull and brain and stayed in intensive care at Olivos between November 4-11. He then was sent recover to a private home where he died on November 25 of 2020 at the age of 60. The deficiencies in Maradona's home care are one of the prosecution's key pieces of evidence against the defendants. A cardiologist testified that he was against moving Maradona from the Olivos Clinic. Advertisement Mr Dimitroff said the surgery was not 'an emergency', although there were indicators 'that it was necessary at some point'. The operation was performed by a neurosurgeon at that centre and it was routine, according to the medical director. After the surgery, the former player displayed a 'difficult' temperament during his stay in intensive care and 'did not understand that he had to stay still', Mr Dimitroff said. He added that on November 6, Maradona had 'a complex psychomotor excitation episode' that resembled alcohol withdrawal, which was what he was demanding, the manager indicated. Advertisement 'We were dealing with an aggressive patient who tore out his own IVs; he was a very difficult patient to take home,' Mr Dimitroff stated. Mr Dimitroff explained that he discussed the situation with Mr Luque and Agustina Cosachov — Maradona's psychiatrist, who is also on trial — and with the former player's family. According to Mr Dimitroff, both Mr Luque and Ms Cosachov requested sedation for Maradona which was carried out at the clinic for approximately 24 hours.
Associated Press
06-05-2025
- Health
- Associated Press
Maradona requested alcohol and 'tore out his own IVs' in days after surgery
BUENOS AIRES, Argentina (AP) — The director of the clinic where Diego Maradona had surgery two weeks before his death in 2020 testified Tuesday that the Argentine soccer star requested alcohol during the post-operative period and was difficult to deal with, which made his subsequent recovery in home care inadvisable. Pablo Dimitroff, medical director of the Olivos Clinic, said that neurosurgeon Leopoldo Luque, one of the seven health professionals on trial requested 'a place' so the former player could undergo surgery in early November 2020. Maradona had surgery for a hematoma that formed between his skull and brain and stayed in intensive care at Olivos between Nov. 4-11. He then was sent recover to a private home where he died on Nov. 25 of 2020 at age 60. The deficiencies in Maradona's home care are one of the prosecution's key pieces of evidence against the defendants. A cardiologist testified that he was against moving Maradona from the Olivos Clinic. Dimitroff said the surgery was not 'an emergency,' although there were indicators 'that it was necessary at some point.' The operation was performed by a neurosurgeon at that center and it was routine, according to the medical director. After the surgery, the former player displayed a 'difficult' temperament during his stay in intensive care and 'did not understand that he had to stay still,' Dimitroff said. He added that on Nov. 6, Maradona had 'a complex psychomotor excitation episode' that resembled alcohol withdrawal, which was what he was demanding, the manager indicated. 'We were dealing with an aggressive patient who tore out his own IVs; he was a very difficult patient to take home,' Dimitroff stated. Dimitroff explained that he discussed the situation with Luque and Agustina Cosachov — Maradona's psychiatrist, who is also on trial — and with the former soccer player's family. According to Dimitroff, both Luque and Cosachov requested sedation for Maradona which was carried out at the clinic for approximately 24 hours. ___ AP soccer:
