Tag Archives: Unravels

Asteroid Collision Near a Nearby Star Unravels Cosmic Mystery

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Composite image of Fomalhaut’s dust belt (center hidden). The inset displays dust cloud cs1 taken in 2012 together with dust cloud cs2 from 2023.

NASA, ESA, Paul Karas/University of California, Berkeley

Around the star Fomalhaut, asteroids are involved in collisions that generate massive dust clouds. This is the first time astronomers are witnessing these events, offering insights into the early days of our solar system.

Fomalhaut has had its share of unusual findings. In 2008, Paul Kalas, based on observations from the Hubble Space Telescope in 2004 and 2005, reported a potential giant planet orbiting the young star. Over the years, however, the nature of this peculiar object, dubbed Fomalhaut b, has sparked heated debates. It could either be a planet slightly larger than Jupiter or simply a cloud of debris.

Now, Kalas and his team have revisited Fomalhaut using Hubble. “In 2023, we utilized the same equipment as before, and Fomalhaut b was undetectable. It was effectively gone,” says Kalas, “What appeared was a new Fomalhaut b.”

This new bright feature, named Fomalhaut CS2 (short for “circumstellar light source”), cannot be a planet, as it would have been identified earlier. The leading theory is that it represents a dust cloud resulting from the collision of two large asteroids or planetesimals, each approximately 60 kilometers in diameter. The disappearance of Fomalhaut b implies that it may have been a similar dust cloud all along.

“These sources exhibit noise and instability, so we’re still far from drawing definitive conclusions,” notes David Kipping at Columbia University. “Yet, all existing evidence aligns well with a broader narrative of collisions between protoplanets in nascent systems.”

Interestingly, it’s unexpected to observe such a significant break twice. “The hypothesis suggests that we shouldn’t witness such impacts more than once every 100,000 years, if not even more infrequently. And yet, for some unexplained reason, we seem to observe it twice within 20 years,” Kalas explains. “Fomalhaut lights up like a holiday tree and it’s astounding.”

This might indicate that collisions among planetesimals are occurring more frequently than previously thought, particularly around relatively young stars like Fomalhaut. Kalas and his team plan to conduct further observations over the next three years utilizing both Hubble and the more powerful James Webb Space Telescope (JWST) to track the behavior of Fomalhaut CS2 and attempt to pick up faint signals from Fomalhaut b.

This presents a rare opportunity to witness these collisions first-hand. “To comprehend these violent phenomena, we no longer need to rely solely on theoretical models; we can observe them in real time,” Kalas states. Further observations may enlighten us not only about young planetary systems generally but also about our own early solar system’s position in the cosmic landscape.

“We have long pondered whether the collisions that formed our moon are typical of what occurs throughout the universe, and now we have strong evidence suggesting they are indeed common,” Kipping remarked. “Perhaps we are not as unique as some may assume.”

Exploring the Mysteries of the Universe: Cheshire, England

Join a weekend with some of science’s brightest minds as you delve into the mysteries of the universe, featuring a tour of the renowned Lovell Telescope.

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Source: www.newscientist.com

Ancient DNA unravels the evolutionary history of Australian dingoes

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Dingoes are found across most of the Australian continent.

Dominique Jeanmaire/Getty Images/iStockphoto

Analysis of ancient dingo DNA suggests that Australia's native wild dogs arrived in two migration waves between 3,000 and 8,000 years ago, and show little evidence of interbreeding with domestic dogs.

Sally Wasef Researchers from the Queensland University of Technology in Australia looked at 42 ancient dingo specimens, ultimately obtaining nine complete genomes, including the oldest genome of any Australian species sequenced to date, as well as mitochondrial DNA from 16 animals.

The DNA recovered dates from 400 to 2,700 years ago and was collected from across the continent. The researchers compared this ancient data with DNA from 11 modern dingoes, six New Guinea singing dogs, and 372 domestic dogs, wolves, and other canines collected in previous studies.

The analysis confirmed that Australia's two main dingo populations – those concentrated on the east and west coasts – diverged at least 3,000 years ago, and because the east coast dingoes are more closely related to the singing dogs of New Guinea than are the west coast dingoes, it is possible that dingoes migrated to Australia in two waves.

Because no DNA from ancient New Guinea singing dogs was found, the researchers could not rule out the possibility that the singing dogs were descended from dingoes that migrated to New Guinea from Australia.

People have long known that dingoes descended from wolves, but “without ancient DNA we couldn't figure that out,” Wassef said.

Since Europeans arrived in Australia, dingoes have been hunted and killed as a threat to the livestock industry.

In recent years, there have been a number of dingo attacks on humans on K'gari Island, also known as Fraser Island, off the coast of Queensland, leading to the animals being euthanized.

Analysis of ancient DNA found no evidence that the K'gari dingoes interbred with domestic dogs. “It's been suggested that dingoes interbred with domestic dogs to provide an excuse to kill them,” Wassef said. “Our results don't show evidence of widespread interbreeding.”

To protect K'gari dingoes' gene pool, Wassef said the practice of euthanizing dingoes may need to be reconsidered: “K'gari dingoes already suffer from inbreeding and killing individuals would significantly reduce their DNA.”

“This study is exciting because it provides some of the data we need to investigate the evolutionary relationships between dingoes, New Guinea singing dogs, dog populations around the world and wolves,” Kylie Cairns At the University of New South Wales, Sydney.

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Source: www.newscientist.com

New Study Unravels the Varied Emotional Purpose of Dreams in Different Locations

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Dreaming is a complex neurophysiological experience that is influenced by the sociocultural environment, and recent research has compared the dreams of forager communities in Tanzania and the Democratic Republic of the Congo with those in Europe and North America, and has Differences in tone and simulation of real-life situations became apparent. This study shows that dreams reflect social norms and values, suggesting a link between dream content and an individual’s sociocultural life.

A study conducted by researchers at the University of Geneva (UNIGE) and the University of Toronto revealed that dreams have a variety of emotional functions.

Why do we dream? This phenomenon is rooted in neurophysiological processes in the brain and manifests as multifaceted, often emotionally charged experiences that can mimic aspects of reality to varying degrees. However, the definitive reason for dreaming remains unclear. A new study jointly conducted by the University of Geneva (UNIGE), the University of Toronto and the University Hospitals of Geneva (HUG) compares the dreams of her two hunting communities in Tanzania and the Democratic Republic of the Congo with those of individuals living in Africa. did. Europe and North America.

It showed that the first two groups not only produced more threatening dreams but also more cathartic and socially oriented dreams than the Western group.These results will be read scientific reportshows how strong the link between sociocultural environment and dream function is.

Dreams are hallucinatory experiences common to all humankind. This occurs most often during a paradoxical phase of sleep known as the rapid eye movement (REM) phase. However, it can occur during any sleep stage.

What is the physiological, emotional and cultural function of dreams? Do they regulate our emotions? Does it prepare us to deal with certain situations? Recent theories suggest that during “functional” dreaming, individuals simulate more threatening or social situations, which may have an evolutionary advantage in promoting adaptive behavior in real-life situations. It suggests that it is possible.

Dream results vary depending on environment and population studied

To test these theories, researchers from UNIGE and the University of Toronto compared the dream content of the Bayaka people of the Democratic Republic of the Congo and the Hadza people of Tanzania, two communities that approximate a hunter-gatherer lifestyle. . Ancestry – Ancestry of a diverse group of individuals living in Europe and North America (Switzerland, Belgium, Canada), including healthy participants and patients with mental disorders.

Bayaka and Hadza dream stories were collected over two months in the field by anthropologists from the University of Toronto. Data on dreams in Western groups comes from previous studies published between 2014 and 2022.

“We found that Bayaka and Hadza dreams are very dynamic. They often begin in dangerous, life-threatening situations, whereas the Western groups we observed In contrast, in clinical populations, such as patients suffering from nightmares or social anxiety, dreams may be intense but do not involve cathartic emotional resolution. “The latter group seems to lack the adaptive function of dreaming,” says Lampros, a private professor and group leader in the Department of Psychiatry and Basic Neuroscience at UNIGE School of Medicine, and HUG’s attending physician.・Mr. Perogamvros explains. The Center for Sleep Medicine led the study.

A mirror that reflects social structure

The researchers found that among the responses Native Americans have when faced with threats in dreams, those related to social support are very frequent. For example, an indigenous person reports a dream in which he was run over by a buffalo in the middle of the bush and was rescued by a member of his community. Or someone may have a dream where they fall into a well and one of their friends saves them. These dreams contain their own emotional resolutions.‘

“Social bonds are necessarily very strong among the Bayaka and Hadza people. Daily life and the division of labor are typically more egalitarian when compared to the more individualistic societies of Europe and North America. This kind of dependence on social connections and community means that the best way for them to process the emotional content associated with threats in their dreams is to take advantage of the social relationships they have. “In fact, these relationships are emotional tools used to process life’s challenges,” says John, an associate professor of evolutionary anthropology at the University of Toronto in Mississauga and lead author of the study. David Samson explains. Therefore, the research team suggests that there is a close relationship between the function of dreams and the social norms and values ​​of each specific society studied.

“However, this study makes it difficult to infer a causal relationship between dreams and daytime activity. Nor should we conclude that dreams in Western populations have no emotional function.”・Mr. Perogamvros added. In fact, in 2019, the same research team found that “bad dreams” in Western people, dreams with negative content that are not nightmares, are often simulations of our fears, and that once we wake up, we are faced with our fears. published a study showing that they are preparing to do so. I’m awake. “There appears to be more than one type of ‘functional’ dream. This study shows that there is a strong link between our sociocultural lives and the function of dreams,” the researchers said. concludes.

Reference: “Evidence for the Emotionally Adaptive Function of Dreams: A Cross-Cultural Study” David R. Samson, Alice Clerge, Nour Abbas, Jeffrey Senese, Marika S. Sarma, Sheena Lou-Levi, Ibrahim A.・Mabulla, Audax ZP Mabulla, Valcy Miegacanda, Francesca Borghese, Pauline Henkarz, Sophie Schwartz, Virginie Starpenich, Lee T. Gettler, Adam Boyett, Alyssa N. Crittenden, Lampros Perroganvros, 2023 October 2nd, scientific report.
DOI: 10.1038/s41598-023-43319-z

Source: scitechdaily.com