Philippa Kaur

More stories

  • 150 Shares149 Views

    in Humans

    Curly hair may have evolved to protect early humans from the sun

    In the first study to look at the evolution of hair types, researchers found tightly coiled hair provides a trade-off of shielding the head from the sun while minimising unwanted insulating

    Humans

    14 February 2023

    By Michael Le Page
    Hair type has previously been studied by researchers in fields such as cosmetics and forensics, but not from an evolutionary perspectiveMireya Acierto/Getty Images
    Hair that is tightly coiled offers the best protection against the sun’s potentially damaging rays, which could explain why this trait evolved in early humans in Africa and straighter hair emerged as some humans moved into cooler areas.
    It has long been suggested that the reason our body hair became so fine that it is sometimes barely visible, while our scalp hair remained thick, is to prevent our heads … More

  • 125 Shares129 Views

    in Space & Astronomy

    The James Webb telescope spotted the earliest known ‘quenched’ galaxy

    The James Webb Space Telescope has spotted the earliest known galaxy to abruptly stop forming stars.

    The galaxy, called GS-9209, quenched its star formation more than 12.5 billion years ago, researchers report January 26 at arXiv.org. That’s only a little more than a billion years after the Big Bang. Its existence reveals new details about how galaxies live and die across cosmic time.

    “It’s a remarkable discovery,” says astronomer Mauro Giavalisco of the University of Massachusetts Amherst, who was not involved in the new study. “We really want to know when the conditions are ripe to make quenching a widespread phenomenon in the universe.” This study shows that at least some galaxies quenched when the universe was young.

    Science News headlines, in your inbox

    Headlines and summaries of the latest Science News articles, delivered to your email inbox every Thursday.

    Thank you for signing up!

    There was a problem signing you up.

    GS-9209 was first noticed in the early 2000s. In the last few years, observations with ground-based telescopes identified it as a possible quenched galaxy, based on the wavelengths of light it emits. But Earth’s atmosphere absorbs the infrared wavelengths that could confirm the galaxy’s distance and that its star-forming days were behind it, so it was impossible to know for sure.

    So astrophysicist Adam Carnall and colleagues turned to the James Webb Space Telescope, or JWST. The observatory is very sensitive to infrared light, and it’s above the blockade of Earth’s atmosphere (SN: 1/24/22). “This is why JWST exists,” says Carnall, of the University of Edinburgh. JWST also has much greater sensitivity than earlier telescopes, letting it see fainter, more distant galaxies. While the largest telescopes on the ground could maybe see GS-9209 in detail after a month of observing, “JWST can pick this stuff up in a few hours.”

    Using JWST observations, Carnall and colleagues found that GS-9209 formed most of its stars during a 200-million-year period, starting about 600 million years after the Big Bang. In that cosmically brief moment, it built about 40 billion solar masses’ worth of stars, about the same as the Milky Way has.

    That quick construction suggests that GS-9209 formed from a massive cloud of gas and dust collapsing and igniting stars all at once, Carnall says. “It’s pretty clear that the vast majority of the stars that are currently there formed in this big burst.”

    Astronomers used to think this mode of galaxy formation, called monolithic collapse, was the way that most galaxies formed. But the idea has fallen out of favor, replaced by the notion that large galaxies form from the slow merging of many smaller ones (SN: 5/17/21).

    “Now it looks like, at least for this object, monolithic collapse is what happened,” Carnall says. “This is probably the clearest proof yet that that kind of galaxy evolution happens.”

    Subscribe to Science News

    Get great science journalism, from the most trusted source, delivered to your doorstep.

    As to what caused the galaxy’s star-forming frenzy to suddenly stop, the culprit appears to be an actively feeding black hole. The JWST observations detected extra emission of infrared light associated with a rapidly swirling mass of energized hydrogen, which is a sign of an accreting black hole. The black hole appears to be up to a billion times the mass of the sun.

    To reach that mass in less than a billion years after the birth of the universe, the black hole must have been feeding even faster earlier on in its life, Carnall says (SN: 3/16/18). As it gorged, it would have collected a glowing disk of white-hot gas and dust around it.

    “If you have all that radiation spewing out of the black hole, any gas that’s nearby is going to be heated up to an incredible extent, which stops it from falling into stars,” Carnall says.

    More observations with future telescopes, like the planned Extremely Large Telescope in Chile, could help figure out more details about how the galaxy was snuffed out. More

  • 113 Shares179 Views

    in Humans

    Early hominin Paranthropus may have used sophisticated stone tools

    Stone tools discovered in Kenya are the oldest Oldowan-type implements found, dating back at least 2.6 million years, and they may have been made by our relative Paranthropus

    Humans

    9 February 2023

    By Michael Marshall
    Reconstruction of Paranthropus, an early hominin whose teeth were found alongside stone tools at Nyayanga, KenyaELISABETH DAYNES/SCIENCE PHOTO LIBRARY
    A set of stone tools found in Kenya is the oldest of its kind, and one of the oldest known to have been made by ancient hominins. The find adds to the evidence for widespread tool use relatively early in human evolution.
    The artefacts were found with two teeth belonging to hominins called Paranthropus. They weren’t thought to make tools because their teeth were well-suited to chewing food, but the new find suggests they actually did make and use stone tools.
    The finds come from Nyayanga on the north-eastern shore of Lake Victoria in Kenya. Tom Plummer at Queens College, City University of New York first learned of them more than 20 years ago, when he was working at another archaeological dig nearby. There, team member Blasto Onyango at the National Museums of Kenya in Nairobi mentioned a different site with similar tools. “We surveyed,” says Plummer, “we saw some material on the surface”, but it took until 2015 to begin full excavations.Advertisement
    The team has since recovered 330 stone artefacts. They include the heavy cores of pebbles, used for pounding, and sharp cutting flakes that had been removed from them. The tools are a type known as Oldowan, named for Oldupai gorge in Tanzania where the first examples were found.
    Based on analyses of the sediments in which the Nyayanga tools were found, and the types of fossils found with them, the team estimates they are between just over 3 million and 2.6 million years old. “We think it’s in the older end of that range,” says Plummer. This would make them the oldest Oldowan tools on record. Previously, the oldest known examples were those from Ledi-Geraru in Ethiopia, which are from 2.6 million years ago.
    The Nyayanga tools were used to process a variety of foods, says Rahab Kinyanjui, also at the National Museums of Kenya. The team found bones of hippopotamus-like animals, some of which had cut marks on them, suggesting the tools were used for butchery. The heavier implements were also used to pound plant materials like tubers and fruit.
    Early Oldowan stone tools from Nyayanga, KenyaT.W. Plummer, J.S. Oliver, and E. M. Finestone, Homa Peninsula Paleoanthropology Project
    Finding evidence of Oldowan tool use this early in Kenya, and 1300km from Ledi-Geraru in Ethiopia, suggests stone tool use was already widespread, says Plummer. In line with this, stone tools have been found in Algeria from 2.4 million years ago.
    The use of such implements is primarily associated with the Homo genus, which includes our own species Homo sapiens, as well as older ones like Homo erectus. The oldest purported Homo remains are 2.8 million years old, but none have been found at Nyayanga. The only hominin remains there so far are of Paranthropus.
    Paranthropus lived alongside other hominins, including Homo, for over a million years. However, it is generally thought that they have no living descendants. Compared with other hominins from the same time, they looked less like us: in particular, they had very large teeth, perhaps for grinding up tough plant foods.
    “The thing about Paranthropus is they’ve got a really specialised anatomy,” says Plummer. “They’ve got the biggest jaws and teeth of any primate that ever lived, for their weight.” He says it is unlikely that a tool-using animal would need such powerful chewing apparatus. Nevertheless, it is the only hominin found at Nyayanga so far, so he says it is worth seriously considering that Paranthropus made and used the tools.
    Others are less hesitant. “People are very shy about saying that it was not Homo something, Homo habilis or whatever, making tools,” says Margherita Mussi of the Italo-Spanish Archaeological Mission at Melka Kunture and Balchit, based in Rome. She points out that several modern primates sometimes make crude stone tools, including chimpanzees and various monkeys. “So why not a Paranthropus?”

    If that is true, it would fit with other evidence that species of Homo were not the only hominins that made stone tools. The oldest known stone tools of any kind, at 3.3 million years old, are from Lomekwi in Kenya. They are cruder than Oldowan versions and were made in a different way: by hitting rocks on the ground, rather than by hitting a rock held in the hand.
    “We have no genus Homo at that time,” says Sonia Harmand at Stony Brook University in New York, one of the discoverers of the Lomekwi tools. “We already know that the first stone tools were probably not made by Homo.” Australopithecus species are likely candidates.
    For the later Nyayanga tools, there were probably late Australopithecus, early Paranthropus and early Homo in the region. “We have to imagine it’s all these species probably sharing the same territory or the same environment at the same time,” says Harmand.
    Studies like these suggest tool use goes back further than we thought, says Plummer. “We’re going to be pushing tool use further back in time,” he says. Furthermore, “tool use was more important earlier on than we realised”.
    In line with this, Mussi and her colleagues showed last month that some hominins were making obsidian tools in organised “workshops” 1.2 million years ago, 500,000 years earlier than thought. “I think that we are systematically under-evaluating hominins,” says Mussi.

    Sign up to Our Human Story, a free monthly newsletter on the revolution in archaeology and human evolution

    More on these topics: More

  • 138 Shares129 Views

    in Humans

    Marvel's Midnight Suns review: Meet your heroes in new strategy game

    In Marvel’s Midnight Suns, you are in charge of a team of superheroes who fight villains but also hang out. Who wouldn’t want to go fishing with Spider-Man or play video games with Wolverine, asks Jacob Aron

    Humans

    8 February 2023

    By Jacob Aron
    Try explaining Doctor Strange’s powers in terms of science2K Games
    Marvel’s Midnight Suns
    Firaxis Games
    PC, PlayStation 4 and 5, Xbox One and Series S/X, Nintendo Switch
    WHILE we wait for a rash of new games to arrive (see my previous column), I have been mopping up a few from last year that I hadn’t yet managed to finish.
    The one that has been occupying most of my time is Marvel’s Midnight Suns, which puts you in charge of a team of famous superheroes. You play as a new character … More

  • 113 Shares149 Views

    in Humans

    Don't Miss: Marvel's Ant Man and the Wasp: Quantumania

    New Scientist’s weekly round-up of the best books, films, TV series, games and more that you shouldn’t miss

    Humans

    8 February 2023

    Disney
    Watch
    Ant-Man and the Wasp: Quantumania stars Paul Rudd (pictured above) as petty thief-turned-Avenger Scott Lang in a new Marvel movie. Set in the Quantum Realm, Lang faces Kang the Conqueror. On general release 17 February.

    Read
    This Won’t Hurt says Marieke Bigg, tongue firmly in cheek, as she explains how medicine fails women, from research to diagnosis and treatment. Today’s landscape, she argues, was designed for men. On sale from 16 February.

    Visit
    Unlocking the mysteries of the heart is a talk by Sian Harding based on her book The Exquisite Machine. … More

  • 138 Shares189 Views

    in Humans

    A three-year drought may have brought down the ancient Hittite empire

    Wood from a burial chamber in modern Turkey reveals there was a sudden severe drought around the time Hittite cities were abandoned 3000 years ago

    Humans

    8 February 2023

    By Clare Wilson
    A burial mound in Gordion, an archaeological site in Turkey, which was the source of wood samples that gave a record of the climate centuries beforeJohn Marston
    A three-year-drought may have led to the fall of the Hittite empire in the Middle East 3000 years ago.
    The finding comes from analysing timber used to make the burial chamber of a later ruler, who may have been the father of King Midas, referred to in Greek legends.
    The sudden drought “would have undoubtedly caused mass problems with food provision. That would have affected the tax base of the empire pretty dramatically,” says Sturt Manning at Cornell University in Ithaca, New York.Advertisement
    The Hittite empire, which encompassed most of what is now Turkey and lasted nearly five centuries, was one of the major geopolitical forces of the ancient world, with a mastery of ironwork, a cuneiform writing system and an army that could take on neighbouring Egypt.
    Ancient texts and archaeological discoveries suggest that around 1200 BC, cities began being abandoned and the empire splintered into independent states that were later overwhelmed by Assyrians from the east.
    Several causes have been proposed, including disease, famine, a centuries-long shift to a drier climate, as well as earlier invasions by mysterious groups named “Sea Peoples” in Egyptian texts.
    Now, Manning’s team has found evidence of a sharp and severe drought from a huge chamber tomb built in the city of Gordion in 748 BC. As the tomb’s mound is much bigger than others nearby, and was made about the time the local King Midas took the throne, some archaeologists say it could have been made for Midas’s father, the previous ruler – although nothing to identify the occupant remains.
    Wood sample showing reduced growth for three consecutive yearsBrita Lorentzen
    Clues to the fall of the Hittites, centuries earlier, come from the juniper logs making up the burial chamber. The logs were taken from 18 trees, which were growing from the period 1775 to 748 BC.
    Less rainfall means less tree growth, which shows up as narrower gaps between tree rings. The logs show there were 80 instances of two or more consecutive years with low rainfall, and one of these was the three years from 1198 to 1196 BC – just when Hittite cities started being abandoned.
    This was supported by another kind of test, measuring the ratio of different forms of carbon from samples of the wood. This shows gradually increasing dryness of the atmosphere between 1300 and 1200 BC, then spikes of dryness from 1222 to 1195 BC.
    “Most traditional societies had some storage that would have helped them through one bad harvest,” says Manning. “By the time you get to a third one in a row, it’s become a crisis.”
    Alan Greaves at the University of Liverpool in the UK, who wasn’t involved in the research, says the results shed new light on the climate changes at the time. “How do you pay for soldiers, how do you pay for artisans to make things?” he says. “A short, sharp drought would be enough to topple a very centralised state based heavily on grain and the gathering in and distribution of agricultural goods.”

    More on these topics: More

  • 125 Shares149 Views

    in Space & Astronomy

    The Kuiper Belt’s dwarf planet Quaoar hosts an impossible ring

    The dwarf planet Quaoar has a ring that is too big for its metaphorical fingers. While all other rings in the solar system lie within or near a mathematically determined distance of their parent bodies, Quaoar’s ring is much farther out.

    “For Quaoar, for the ring to be outside this limit is very, very strange,” says astronomer Bruno Morgado of the Federal University of Rio de Janeiro. The finding may force a rethink of the rules governing planetary rings, Morgado and colleagues say in a study published February 8 in Nature.

    Science News headlines, in your inbox

    Headlines and summaries of the latest Science News articles, delivered to your email inbox every Thursday.

    Thank you for signing up!

    There was a problem signing you up.

    Quaoar is an icy body about half the size of Pluto that’s located in the Kuiper Belt at the solar system’s edge (SN: 8/23/22). At such a great distance from Earth, it’s hard to get a clear picture of the world.

    So Morgado and colleagues watched Quaoar block the light from a distant star, a phenomenon called a stellar occultation. The timing of the star winking in and out of view can reveal details about Quaoar, like its size and whether it has an atmosphere.

    The researchers took data from occultations from 2018 to 2020, observed from all over the world, including Namibia, Australia and Grenada, as well as space. There was no sign that Quaoar had an atmosphere. But surprisingly, there was a ring. The finding makes Quaoar just the third dwarf planet or asteroid in the solar system known to have a ring, after the asteroid Chariklo and the dwarf planet Haumea (SN: 3/26/14; SN: 10/11/17).

    Even more surprisingly, “the ring is not where we expect,” Morgado says.

    Known rings around other objects lie within or near what’s called the Roche limit, an invisible line where the gravitational force of the main body peters out. Inside the limit, that force can rip a moon to shreds, turning it into a ring. Outside, the gravity between smaller particles is stronger than that from the main body, and rings will coalesce into one or several moons.

    “We always think of [the Roche limit] as straightforward,” Morgado says. “One side is a moon forming, the other side is a ring stable. And now this limit is not a limit.”

    For Quaoar’s far-out ring, there are a few possible explanations, Morgado says. Maybe the observers caught the ring at just the right moment, right before it turns into a moon. But that lucky timing seems unlikely, he notes.

    Maybe Quaoar’s known moon, Weywot, or some other unseen moon contributes gravity that holds the ring stable somehow. Or maybe the ring’s particles are colliding in such a way that they avoid sticking together and clumping into moons.

    The particles would have to be particularly bouncy for that to work, “like a ring of those bouncy balls from toy stores,” says planetary scientist David Jewitt of UCLA, who was not involved in the new work.

    The observation is solid, says Jewitt, who helped discover the first objects in the Kuiper Belt in the 1990s. But there’s no way to know yet which of the explanations is correct, if any, in part because there are no theoretical predictions for such far-out rings to compare with Quaoar’s situation.

    That’s par for the course when it comes to the Kuiper Belt. “Everything in the Kuiper Belt, basically, has been discovered, not predicted,” Jewitt says. “It’s the opposite of the classical model of science where people predict things and then confirm or reject them. People discover stuff by surprise, and everyone scrambles to explain it.”

    More observations of Quaoar, or more discoveries of seemingly misplaced rings elsewhere in the solar system, could help reveal what’s going on.

    “I have no doubt that in the near future a lot of people will start working with Quaoar to try to get this answer,” Morgado says. More

  • 138 Shares129 Views

    in Humans

    Neolithic complex dubbed ‘Stonehenge of the North’ opens to UK public

    Two sections of the Thornborough Henges near Ripon, UK, have been donated to the public body Historic England in an effort to preserve the millennia-old monuments

    Humans

    3 February 2023

    By Madeleine Cuff
    The central of the three Thornborough HengesHistoric England
    Thornborough Henges, a Neolithic complex near Ripon in North Yorkshire, UK, known as the “Stonehenge of the North”, has been donated to public ownership and is now open to visitors.  
    The site dates from 3500 to 2500 BC and features three earth circles, each 4 metres high and 200 metres across. The earthworks were probably used as ceremonial gathering places and trading centres by early Britons, archaeologists believe. 
    Two of the three henges have been donated to the public body Historic England by building firm Tarmac. They are now under the care of the charity English Heritage and are free for the public to visit. Lightwater Holdings, a local company, has also donated parts of the wider monument. Advertisement
    The henges are “a link to our ancient ancestors, through thousands of years, inspiring a sense of wonder and mystery”, Duncan Wilson at Historic England said in a statement.
    “We are thrilled to have acquired this highly significant site for the nation, ensuring that these magnificent monuments are safe and will be preserved for generations to come.” 
    The southern and central hengesHistoric England
    The transfer of ownership means the two earthworks will be removed from Historic England’s risk register. They have been on the register since 2009, over concerns the sites were being eroded by livestock and rabbits.  
    Today, all three henges are visible as large, circular banks, but thousands of years ago, they would have stood above wetlands. They may have been covered in a sulphate mineral known as gypsum, creating white landmarks visible for miles.  
    The site’s opening to the public will bring its story to new audiences, according to Kate Mavor at English Heritage. “Thornborough Henges is one of the most important ancient sites in Britain and yet almost completely unknown. We are looking forward to sharing its significance, its stories and its secrets with the public,” she said in a statement. 

    More on these topics: More