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    A cosmic census triples the known number of black holes in dwarf galaxies

    A colossal census of the cosmos has more than tripled the number of active black holes known to reside in miniature galaxies and found the biggest haul of middleweight black holes to date.

    The survey turned up about 2,500 dwarf galaxies with actively feeding black holes at their centers, up from about 500 known before, researchers report in a paper submitted October 31 to arXiv.org. The team also found nearly 300 new intermediate-mass black hole candidates, an increase from about 70 previous possible detections (SN: 9/2/20). More

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    DNA analysis rewrites the stories of people buried in Pompeii

    Plaster casts of people who died in Pompeii. DNA tests show the adult on the right was a male unrelated to the small child on his lap.Archeological Park of Pompei
    Pompeii’s plaster cast human figures aren’t who they were assumed to be, genetic tests have revealed, highlighting the way idealised stories can be projected onto archaeological evidence.
    The analysis also reveals that the demography of Pompeii was also far more complicated and diverse than previously thought.
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    When Vesuvius erupted in AD 79, it buried several Roman towns, including Pompeii. Many of Pompeii’s residents were completely smothered in compacted ash during the eruption and, as their bodies decayed, cavities formed that perfectly preserved their positions in their final moments.
    In the 19th century, archaeologists developed a method of pouring plaster into the cavities to make life-like casts. Since then, more than 100 of these casts have been made, preserving the victims’ shapes along with any remaining bones that hadn’t decayed over the centuries.
    However, it has long been known that many of the plaster casts were manipulated into different poses and sometimes placed together to add to the drama of the Pompeii story, says Valeria Amoretti at the Archaeological Park of Pompeii in Naples, Italy.
    To learn more about who these people were, Amoretti and her colleagues examined 14 of the plaster casts and extracted DNA from bones in five of them.
    What they found has completely altered the established interpretations of who they were. An adult wearing a golden bracelet with a child on their lap was long believed to be the child’s mother. The DNA analysis shows they are actually an adult male who is biologically unrelated to the child. A nearby figure, formerly interpreted as being the father, was also unrelated to the supposed mother and child.
    Another pair, who were thought to be sisters or a mother and daughter who died in an embrace, included at least one genetic male and were also unlikely to have been related.
    The genetic analysis further revealed that the people of Pompeii had diverse ancestry, with components related to modern eastern Mediterranean, Levantine and North African Jewish populations.

    Amoretti says it is no surprise that the Roman world was multicultural, and that the Mediterranean and its ports united people.
    “But it is extremely interesting to discover the extent of this melting pot, even in an average provincial town like Pompeii, and to have scientific proof of it from ancient DNA,” she says.
    Alissa Mittnik at Harvard University says the study highlights the importance of applying science before interpreting archaeology at face value.
    “Ultimately, it reminds us that the most intuitive, dramatic or sensational explanations do not always hold true, encouraging us to stay aware of and question our preconceived notions,” she says.

    Topics:archaeology More

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    A star winked out of sight. Could it be a ‘failed supernova’? 

    Some massive stars may go out with a fizzle, not a bang.

    A star that winked out of view could be a “failed supernova,” a stellar explosion that petered out instead of fully detonating, a new study reports. If real, the failed supernova would mark the birth of a black hole.

    At the ends of their lives, massive stars explode in dazzling outbursts known as supernovas, kicked off when the star’s core collapses. But sometimes, scientists suspect, there’s not enough oomph for a full explosion, resulting in a star that switches off without fireworks.  More

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    Ancient Egyptians shaped sheep’s horns – and we don’t know why

    Sheep skulls modified by ancient Egyptians so that their horns grew upward instead of outwardB. De Cupere
    Sheep with deformed horns are among the more mysterious animal remains discovered at an ancient Egyptian burial site dating back to around 3700 BC. They also represent the oldest physical evidence of humans modifying the horns of livestock.
    “The sheep were deliberately made ‘special’ by castration,” says Wim Van Neer at the Royal Belgian Institute of Natural Sciences. “In addition, their horns were directed upward, and in one case, the horns were removed.” More

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    Before the Stone Age: Were the first tools made from plants not rocks?

    Bitter/iStock
    There are few things more irritating in everyday life than getting something stuck between your teeth. Thankfully, we can reach for a toothpick – and it seems our ancient ancestors did the same. In fact, a fragment of a 1.2-million-year-old toothpick is perhaps the earliest direct evidence we have of hominins using plants as tools.
    Our ancient ancestors probably made frequent use of implements made from plants. But finding evidence of this is extremely tough because botanical materials are so quick to rot away. This means the archaeological record of human tool use is deeply skewed towards the much hardier stone.
    All this suggests that the origins of human technology could have been profoundly misunderstood.

    Stone Age
    The conventional view is it all started with the first stone tools and the dawn of the Stone Age over 3 million years ago. But what if, even before that, there was a botanical age, one based on woodworking and weaving of plant materials? For some researchers, it is absurd not to think that plants would be part of the story. “Perishable material culture is an essential element in our evolutionary past,” says Linda Hurcombe at the University of Exeter in the UK.
    Now, we are finally getting a clearer view of this lost age. New techniques are making it possible to find traces of plant-based tools that would otherwise have been missed. And by studying the way modern primates use plants,… More

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    Ancient Mesopotamian clay seals offer clues to the origin of writing

    A cylinder seal and its design imprinted onto clayFranck Raux © 2001 GrandPalaisRmn (Musée du Louvre)
    The world’s oldest known writing system may have had its origins in the imagery on decorated cylinders used to denote ownership. Some of the symbols on these cylinder seals correspond to those used in proto-cuneiform, a form of proto-writing used in Mesopotamia.
    The finding indicates that the invention of writing in Mesopotamia was a decentralised process, in which many people across a wide area contributed to the set of symbols used.
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    “There’s been this longstanding reconstruction of how writing appeared in Mesopotamia, which is arguably the earliest invention of writing in the world,” says Silvia Ferrara at the University of Bologna in Italy. “We’re retracing the trajectory in a way that’s more, I would say, colourful, less straitjacketed.”
    The oldest known true writing system is cuneiform, invented around 3200 BC in Mesopotamia. It was preceded by a simpler system called proto-cuneiform, which was in use from 3350 to 3000 BC.
    Proto-writing like proto-cuneiform is distinguished by a lack of grammatical rules, which means it cannot convey complex meanings, says Amy Richardson at the University of Reading in the UK, who wasn’t involved in the research. For instance, proto-cuneiform can be used to label something as “seven bushels of wheat”, but only true writing like cuneiform can say “seven bushels of wheat will be delivered to you”.
    The origins of proto-cuneiform have often been traced to clay tokens. These came in a variety of shapes, such as discs and spheres, and were often engraved with patterns. The tokens could be pressed into wet clay, creating a symbol. Some of the symbols on the tokens are similar to those found in proto-cuneiform, as documented by Denise Schmandt-Besserat at the University of Texas at Austin in her two-volume book Before Writing in 1992.
    There is some evidence for a role of tokens in the origin of proto-cuneiform, says Ferrara. “But you cannot explain all the signs.”
    Ferrara and her colleagues Kathryn Kelley and Mattia Cartolano, also at the University of Bologna, have instead explored another source of symbols: cylinder seals. These cylindrical objects have patterns and images embossed on them, and leave a rectangular collection of symbols when rolled over sheets of wet clay. The symbols often referred to goods being transported, or to administrators involved in transactions, says Cartolano.
    Two sides of a proto-cuneiform tabletCDLI
    The team examined cylinder seals from a wide area of south-west Asia, including Mesopotamia, that dated to 4400 to 3400 BC. They found several symbols that corresponded to proto-cuneiform symbols.
    “One of the clearest examples that we found is the use of the images of fringed cloth and vessel in a net,” says Cartolano. These have well-understood meanings: they refer to the transport of goods. And they are found both on cylinder seals and proto-cuneiform tablets.
    The idea that the symbols on cylinder seals led to some of the symbols in proto-cuneiform was previously suggested by Holly Pittman at the University of Pennsylvania in Philadelphia in a 1994 book chapter and developed in later publications. “I am gratified that, 30 years after I first proposed the fundamental role of seal imagery in the origins of proto-cuneiform script, that a new generation of scholars have taken up my idea and, with their expertise in cuneiform script, have put details to my argument,” says Pittman. She adds that in the 1990s her idea was dismissed “without serious consideration”.

    “I find it to be very convincing,” says Richardson. “There does seem to be a really neat correlation in the particular examples that they’re illustrating in this article.” Her own research has found that cylinder seals were also used to record interactions between cities.
    This doesn’t mean that tokens didn’t play a role. “I think there’s still some strong arguments to make that those tokens really are part of the foundation of abstraction,” says Richardson. In particular, they seem to have been important for the development of counting systems.
    If proto-cuneiform really did arise in this hodge-podge way, drawn from tokens, cylinder seals and possibly other sources, it may tell us something about who was inventing it, says Ferrara. “There is evidence for making a claim that the invention of writing in Mesopotamia was, in fact, much more decentralised than we think,” she says. While powerful people in the major city of Uruk no doubt played a role, perhaps so did other administrators and tradespeople scattered over the region. “I think there’s evidence for having a more widespread… and more distributed prompt to writing,” she says.
    Writing was first used for administration, not for storytelling. “Those first written records tend to be about trying to organise materials, goods, people, things,” says Richardson. “It’s very much about trying to find ways of creating a social system.”

    Topics:archaeology More

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    A zombie star’s spiky filaments shed light on a 12th century supernova

    Some 6,500 light-years from Earth lurks a zombie star cloaked in long tendrils of hot sulfur.

    Nobody knows how those tendrils formed. But astronomers now know where they’re going. New observations, reported in the Nov. 1 Astrophysical Journal Letters, capture the 3-D structure and motion of debris left in the wake of a supernova that was seen to detonate almost 900 years ago.

    “It’s a piece of the puzzle towards understanding this very bizarre [supernova] remnant,” says astronomer Tim Cunningham of the Harvard & Smithsonian Center for Astrophysics in Cambridge, Mass. More

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    Chilling news adds fresh meaning to 2018 Arctic horror drama

    James Fitzjames (Tobias Menzies, left) and John Franklin (Ciarán Hinds)James Blake/Falklands Maritime Heritage Trust
    The TerrorAMCShowrunners: David Kajganich, Soo Hugh
    In September, an awful truth was brought to light.
    Ever since contact was lost with the Franklin expedition, an 1845 attempt by the British Royal Navy to find a path through the Arctic’s Northwest Passage, historians and scientists have tried to find out what went wrong. Investigations discovered hints of the horrors the sailors may have faced, including pack ice, hypothermia, lead poisoning and starvation. Eventually, the wrecks of HMS Erebus and HMS Terror, the… More