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Dark Energy Could Be Responsible for Mysterious Experiment Signals, Researchers Say – Gizmodo

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The XENON1T Time Projection Chamber TPC in a clean room.
Photo: XENON1T / Purdue University

A team of physicists at the University of Cambridge suspects that dark energy may have muddled results from the XENON1T experiment, a series of underground vats of xenon that are being used to search for dark matter.

Dark matter and dark energy are two of the most discussed quandaries of contemporary physics. The two darks are placeholder names for mysterious somethings that seem to be affecting the behavior of the universe and the stuff in it. Dark matter refers to the seemingly invisible mass that only makes itself known through its gravitational effects. Dark energy refers to the as-yet unexplained reason for the universe’s accelerating expansion. Dark matter is thought to make up about 27% of the universe, while dark energy is 68%, according to NASA.

Physicists have some ideas to explain dark matter: axions, WIMPs, SIMPs, and primordial black holes, to name a few. But dark energy is a lot more enigmatic, and now a group of researchers working on XENON1T data says an unexpected excess of activity could be due to that unknown force, rather than any dark matter candidate. The team’s research was published this week in Physical Review D.

The XENON1T experiment, buried below Italy’s Apennine Mountains, is set up to be as far away from any noise as possible. It consists of vats of liquid xenon that will light up if interacted with by a passing particle. As previously reported by Gizmodo, in June 2020 the XENON1T team reported that the project was seeing more interactions than it ought to be under the Standard Model of physics, meaning that it could be detecting theorized subatomic particles like axions—or something could be screwy with the experiment.

“These sorts of excesses are often flukes, but once in a while they can also lead to fundamental discoveries,” said Luca Visinelli, a researcher at Frascati National Laboratories in Italy and a co-author of the study, in a University of Cambridge release. “We explored a model in which this signal could be attributable to dark energy, rather than the dark matter the experiment was originally devised to detect.”

“We first need to know that this wasn’t simply a fluke,” Visinelli added. “If XENON1T actually saw something, you’d expect to see a similar excess again in future experiments, but this time with a much stronger signal.”

Despite constituting so much of the universe, dark energy has not yet been identified. Many models suggest that there may be some fifth force besides the known four known fundamental forces in the universe, one that is hidden until you get to some of the largest-scale phenomena, like the universe’s ever-faster expansion.

Axions shooting out of the Sun seemed a possible explanation for the excess signal, but there were holes in that idea, as it would require a re-think of what we know about stars. “Even our Sun would not agree with the best theoretical models and experiments as well as it does now,” one researcher told Gizmodo last year.

Part of the problem with looking for dark energy are “chameleon particles” (also known as solar axions or solar chameleons), so-called for their theorized ability to vary in mass based on the amount of matter around them. That would make the particles’ mass larger when passing through a dense object like Earth and would make their force on surrounding masses smaller, as New Atlas explained in 2019. The recent research team built a model that uses chameleon screening to probe how dark energy behaves on scales well beyond that of the dense local universe.

“Our chameleon screening shuts down the production of dark energy particles in very dense objects, avoiding the problems faced by solar axions,” said lead author Sunny Vagnozzi, a cosmologist at Cambridge’s Kavli Institute for Cosmology, in a university release. “It also allows us to decouple what happens in the local very dense Universe from what happens on the largest scales, where the density is extremely low.”

The model allowed the team to understand how XENON1T would behave if the dark energy were produced in a magnetically strong region of the Sun. Their calculations indicated that dark energy could be detected with XENON1T.

Since the excess was first discovered, ​​the XENON1T team “tried in any way to destroy it,” as one researcher told The New York Times. The signal’s obstinacy is as perplexing as it is thrilling.

“The authors propose an exciting and interesting possibility to expand the scope of the dark matter detection experiments towards the direct detection of dark energy,” Zara Bagdasarian, a physicist at UC Berkeley who was unaffiliated with the recent paper, told Gizmodo in an email. “The case study of XENON1T excess is definitely not conclusive, and we have to wait for more data from more experiments to test the validity of the solar chameleons idea.”

The next generation of XENON1T, called XENONnT, is slated to have its first experimental runs later this year. Upgrades to the experiment will hopefully seal out any noise and help physicists home in on what exactly is messing with the subterranean detector.

More: What Is Dark Matter and Why Hasn’t Anyone Found It Yet?

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Guilt, grief and anxiety as young people fear for climate’s future

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Overwhelmed, sad, guilty are some of the emotions young people say they feel when they think of  Climate Change and their concerns world leaders will fail to tackle it.

Broadly referred to as climate anxiety, research has stacked up to measure its prevalence ahead of the U.N. talks in Glasgow, which begin at the end of the month to thrash out how to put the 2015 Paris Agreement on curbing climate change into effect.

One of the biggest studies to date, funded by Avaaz, an online campaign network, and led by Britain’s University of Bath, surveyed 10,000 young people aged 16-25 years in 10 countries. It published its results in September.

It found around three quarters of those surveyed considered the future frightening, while a lack of action by governments and industry left 45% experiencing climate anxiety and distress that affected their daily lives and functioning.

Elouise Mayall, an ecology student at Britain’s University of East Anglia and member of the UK Youth Climate Coalition, told Reuters she had felt guilty and overwhelmed.

“What I’d be left with is maybe the sense of shame, like, ‘how dare you still want lovely things when the world is ending and you don’t even know if you’re going to have a safe world to grow old in’.”

She spoke of conflicting emotions.

“You might have sadness, there might be fear, there might be a kind of overwhelm,” she said. “And maybe even sometimes a quite like wild optimism.”

Caroline Hickman, a psychotherapist and lecturer at the University of Bath and one of the co-authors of the research published in September, is working to help young people manage climate-related emotions.

“They’re growing up with the grief and the fear and the anxiety about the future,” she told Reuters.

“SENSE OF MEANING”

London-based psychiatrist Alastair Santhouse sees climate change, as well as COVID-19, as potentially adding to the burden, especially for those pre-disposed to  anxiety .

For now, climate anxiety alone does not normally require psychiatric help. Painful as it is, it can be positive, provided it does not get out of control.

“Some anxiety about climate change is motivating. It’s just a question of how much anxiety is motivating and how much is unacceptable,” said Santhouse, author of a book that tackles how health services struggle to cope with complex mental issues.

“The worry is that as climate change sets in, there will be a more clear cut mental health impact,” he added.

Among some of the world’s communities that are already the most vulnerable, extreme weather events can also cause problems such as post traumatic stress disorder.

Leading climate campaigner Greta Thunberg, 18, has experienced severe climate anxiety.

“It’s a quite natural response, because, as you see, as the world is today, that no one seems to care about what’s happening, I think it’s only human to feel that way,” she said.

For now, however, she is hopeful because she is doing everything she possibly can.

“When you take action, you also get a sense of meaning that something is happening. If you want to get rid of that anxiety, you can take action against it,” she said.

 

(Reporting by Barbara Lewis; Editing by Alison Williams)

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Rocket failure mars U.S. hypersonic weapon test as others succeed

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The Pentagon ‘s hypersonic weapon programs suffered a setback on Thursday when a booster rocket carrying a hypersonic weapon failed, people briefed on the test result said.

The test was intended to validate aspects of one of the Pentagon’s hypersonic glide vehicles in development, two of the people said.

Hypersonic glide vehicles are launched from a rocket in the upper atmosphere before gliding to a target at speeds of more than five times the speed of sound, or about 3,853 miles (6,200 kilometers) per hour.

In a separate series of tests conducted on Wednesday, the U.S. Navy and Army tested hypersonic weapon component prototypes. That test successfully “demonstrated advanced hypersonic technologies, capabilities, and prototype systems in a realistic operating environment,” the Pentagon said in a statement.

The United States and its global rivals have quickened their pace to build hypersonic weapons – the next generation of arms that rob adversaries of reaction time and traditional defeat mechanisms.

U.S. President Joe Biden expressed concern on Wednesday about Chinese hypersonic missiles, days after a media report that Beijing had tested a nuclear-capable hypersonic glide weapon.

Glide bodies are different from their air-breathing hypersonic weapon cousins which use scramjet engine technology and the vehicle’s high speed to forcibly compress incoming air before combustion to enable sustained flight at hypersonic speeds. An air-breathing hypersonic weapon was successfully tested in September.

Companies such as Lockheed Martin and Raytheon Technologies are working to develop the hypersonic weapon capability for the United States.

(Reporting by Mike Stone and Idrees Ali in Washington; Editing by Sandra Maler)

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Patagonian fossils show Jurassic dinosaur had the herd mentality | Saltwire – SaltWire Network

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By Will Dunham

(Reuters) – A vast trove of fossils unearthed in Argentina’s southern Patagonia region is offering the oldest-known evidence that some dinosaurs thrived in a complex and well-organized herd structure, with adults caring for the young and sharing a communal nesting ground.

Scientists said on Thursday the fossils include more than 100 dinosaur eggs and the bones of about 80 juveniles and adults of a Jurassic Period plant-eating species called Mussaurus patagonicus, including 20 remarkably complete skeletons. The animals experienced a mass-death event, probably caused by a drought, and their bodies were subsequently buried by wind-blown dust, the researchers said.

“It is a pretty dramatic scene from 193 million years ago that was frozen in time,” said paleontologist Diego Pol of the Egidio Feruglio Paleontological Museum in Trelew, Argentina, who led the research published in the journal Scientific Reports.

Mussaurus, which grew to about 20 feet (6 meters) long and about 1.5 tons, possessed a long neck and tail, with a small head. It was bipedal as an adult but newborns were quadrupedal. Mussaurus lived early in the Jurassic, the second of three periods comprising the age of dinosaurs. It was a relatively large beast for its time – much bigger than contemporaneous meat-eating dinosaurs. Dinosaurs became true giants later in the Jurassic.

“The site is one of a kind,” Pol said. “It preserves a dinosaur nesting ground including delicate and tiny dinosaur skeletons as well as eggs with embryos inside. The specimens we have found showed that herd behavior was present in long-necked dinosaurs since their early history. These were social animals, and we think this may be an important factor to explain their success.”

The animals were found to have been grouped by age at the time of their deaths, with hatchlings and eggs in one area while skeletons of juveniles were clustered nearby. The eggs were arranged in layers within trenches. Adults were found alone or in pairs.

This phenomenon, called “age segregation,” signals a complex social structure, the researchers said, including adults that foraged for meals and cared for the young. The researchers suspect that members of the herd returned to the same spot during successive seasons to form breeding colonies.

“The young were staying with the adults at least until they reached adulthood. It could be that they stayed in the same herd after reaching adulthood, but we don’t have information to corroborate that hypothesis,” said paleontologist and study co-author Vincent Fernandez of the Natural History Museum in London.

Herd behavior also can protect young and vulnerable individuals from attack by predators.

“It’s a strategy for the survival of a species,” Fernandez said.

The oldest previous evidence for dinosaur herd behavior was from about 150 million years ago.

The nesting ground was situated on the dry margins of a lake featuring ferns and conifers in a warm but seasonal climate. The eggs are about the size of a chicken’s, and the skeleton of a hatchling fits in the palm of a human hand. The adults got as heavy as a hippo.

A scanning method called high-resolution X-ray computed tomography confirmed that the embryos inside the eggs indeed were of Mussaurus.

Mussaurus was a type of dinosaur called a sauropodomorph, which represented the first great success story among herbivorous dinosaurs. Sauropodomorphs were an evolutionary forerunner to a group called sauropods known for long necks and tails and four pillar-like legs.

The largest land animals in Earth’s history were the sauropod successors of sauropodomorphs, as exemplified by a later denizen of Patagonia called Argentinosaurus that reached perhaps 118 feet (36 meters) in length and upwards of 70 tons.

(Reporting by Will Dunham in Washington, Editing by Rosalba O’Brien)

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