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    Magisteria review: How science and religion have a tangled past

    Anti-evolution books on sale in Dayton, Tennessee, in 1925Hulton-Deutsch Collection/CORBIS/Corbis via Getty Images
    Magisteria
    Nicholas Spencer (Oneworld Publications)
    SCIENCE and religion are in opposition from their foundations upwards, right? One is built on reason and evidence, the other on belief.
    Well, I have a confession to make: I don’t buy it. I am an evangelical Christian and a New Scientist editor. Some might say I am the definition of a square peg in a round hole – but there it is.
    I say all this by way of explaining why I was excited to get hold … More

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    Animalia review: Intriguing sci-fi thriller, shame about the aliens

    Faith, freedom and spirituality are key to a well-made sci-fi psychological thriller, Animalia. But writer-director Sofia Alaoui leaves the aliens dangling in an unsatisfying ending

    Humans

    24 February 2023

    By Davide Abbatescianni
    Oumaïma Barid appears in Animalia by Sofia Alaoui.Courtesy of Sundance Institute
    Animalia
    Sofia Alaoui (director)
    Sundance Film Festival premier
    Animalia, a French-Moroccan-Qatari co-production that premiered at last month’s Sundance Film Festival, opens with an intriguing set-up. A deeply pious pregnant woman of modest origins, Itto (Oumaïma Barid), looks forward to a day of quiet when her rich husband Amine (Mehdi Dehbi) and his family go away on business.
    On the same day, a mysterious state of emergency is declared nationwide. Amine remains stuck somewhere on the other side of Morocco, while … More

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    The Milky Way may be spawning many more stars than astronomers had thought

    The Milky Way is churning out far more stars than previously thought, according to a new estimate of its star formation rate.

    Gamma rays from aluminum-26, a radioactive isotope that arises primarily from massive stars, reveal that the Milky Way converts four to eight solar masses of interstellar gas and dust into new stars each year, researchers report in work submitted to arXiv.org on January 24. That range is two to four times the conventional estimate and corresponds to an annual birthrate in our galaxy of about 10 to 20 stars, because most stars are less massive than the sun.

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    At this rate, every million years — a blink of the eye in astronomical terms — our galaxy spawns 10 million to 20 million new stars. That’s enough to fill roughly 10,000 star clusters like the beautiful Pleiades cluster in the constellation Taurus. In contrast, many galaxies, including most of the ones that orbit the Milky Way, make no new stars at all.

    “The star formation rate is very important to understand for galaxy evolution,” says Thomas Siegert, an astrophysicist at the University of Würzburg in Germany. The more stars a galaxy makes, the faster it enriches itself with oxygen, iron and the other elements that stars create. Those elements then alter star-making gas clouds and can change the relative number of large and small stars that the gas clouds form.

    Siegert and his colleagues studied the observed intensity and spatial distribution of emission from aluminum-26 in our galaxy. A massive star creates this isotope during both life and death. During its life, the star blows the aluminum into space via a strong wind. If the star explodes when it dies, the resulting supernova forges more. The isotope, with a half-life of 700,000 years, decays and gives off gamma rays.

    Like X-rays, and unlike visible light, gamma rays penetrate the dust that cloaks the youngest stars. “We’re looking through the entire galaxy,” Siegert says. “We’re not X-raying it; here we’re gamma-raying it.”

    The more stars our galaxy spawns, the more gamma rays emerge. The best match with the observations, the researchers find, is a star formation rate of four to eight solar masses a year. That is much higher than the standard estimate for the Milky Way of about two solar masses a year.

    The revised rate is very realistic, says Pavel Kroupa, an astronomer at the University of Bonn in Germany who was not involved in the work. “I’m very impressed by the detailed modeling of how they account for the star formation process,” he says. “It’s a very beautiful work. I can see some ways of improving it, but this is really a major step in the absolutely correct direction.”

    Siegert cautions that it is difficult to tell how far the gamma rays have traveled before reaching us. In particular, if some of the observed emission arises nearby — within just a few hundred light-years of us — then the galaxy has less aluminum-26 than the researchers have calculated, which means the star formation rate is on the lower side of the new estimate. Still, he says it’s unlikely to be as low as the standard two solar masses per year.

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    In any event, the Milky Way is the most vigorous star creator in a collection of more than 100 nearby galaxies called the Local Group. The largest Local Group galaxy, Andromeda, converts only a fraction of a solar mass of gas and dust into new stars a year. Among Local Group galaxies, the Milky Way ranks second in size, but its high star formation rate means that we definitely try a lot harder.    More

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    Some of the earliest modern humans in Europe used bows and arrows

    A site in France briefly occupied by modern humans is littered with stone points that were probably used as arrowheads, showing that bows and arrows were used in Europe much earlier than we thought

    Humans

    22 February 2023

    By Michael Le Page
    Reproductions of arrows with flint heads like those found at Grotte Mandrin in FranceLudovic Slimak
    Bows and arrows were first used in Europe much earlier than we previously thought. More than 100 arrowheads have been found in a rock shelter briefly used by a group of modern humans 54,000 years ago in an early foray into Neanderthal territory.
    “It’s incredible how many we have,” says Laure Metz at Aix-Marseille University in France.
    Metz is part of a team that has been excavating a rock shelter called Grotte Mandrin in southern France. This shelter was used first by Neanderthals more than 80,000 years ago, and then by modern humans from about 45,000 years ago – around the time that modern humans displaced Neanderthals all across Europe.Advertisement
    But, last year, the team reported that, for a 40-year period around 54,000 years ago, Grotte Mandrin was used as a hunting camp by a small group of modern humans. The clinching evidence came from a baby tooth that isn’t Neanderthal.
    In the layers of earth from this time, Metz and her colleagues have now reported finding more than a thousand small stone points around 1 or 2 centimetres long. Of these, around 100 have been identified as broken or complete arrowheads, as they have one or more signs of impact damage resembling those seen when the team used newly made stone points as arrowheads. The others may be arrowheads too, but the researchers are unsure.
    “The tips from Mandrin could hardly have been used in any other way than to tip arrows,” says Marlize Lombard at the University of Johannesburg in South Africa, who wasn’t involved in the study.
    Researcher Ludovic Slimak holding a flint point from Grotte MandrinPhilippe PSAILA
    Most of the Mandrin arrowheads are broken. Some are arrowhead tips that broke off inside animals and were brought back to camp inside butchered meat, says Metz. Many of these show signs of charring from fires.
    The parts that remained attached to the shaft have also been found. Because of the work involved in making arrow shafts, says Metz, when an arrowhead broke, hunters would have brought the arrow back to camp and replaced the arrowhead, discarding the broken one.

    Before now, the earliest unambiguous evidence for bows and arrows in Europe came from finds in Stellmoor, Germany, dating to around 10,000 years ago, says Metz. However, it was considered likely that the modern humans who displaced Neanderthals around 45,000 years ago had bows and arrows.
    These humans were definitely using stone-tipped projectiles; the issue is that, with larger stone points, there is no way to tell if they were spearheads or arrowheads, says Metz. At some prehistoric sites in Europe, evidence of arrowheads may have been missed – archaeologists used to throw away smaller bits of stone, she says, regarding them as having no value.
    Bows and arrows were first developed in Africa at least 70,000 years ago. Lombard and others have found stone and bone arrowheads at several sites in southern Africa dating back as far as this. The modern humans who moved out of Africa may have spread the technology around the world.
    Despite presumably seeing bows in action, Neanderthals never developed them, says Metz. They kept using large, stone-tipped spears that were either thrust directly or thrown by hand, and so required close contact with their prey.
    The team has found no evidence that the arrows were used in conflict, but Metz says warfare is so ubiquitous in human societies that she is convinced it took place in prehistory too. She says that, while it is possible that this small group of modern humans was wiped out by Neanderthals despite having technological advantages such as bows and arrows, we just don’t know what happened to them. “We have no idea,” she says.

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    Don't Miss: Explore wildfire's power at Science Gallery London

    Was the shift to farming really the worst mistake in human history?The notion that our ancestors’ shift from a hunter-gatherer lifestyle to farming was disastrous for our health is well established, but a new study should prompt a rethink, says Michael Marshall More

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    Next Exit film review: New tale of the afterlife takes a wrong turn

    Two volunteers sign up for euthanasia to help a research project when evidence of consciousness after death emerges. The idea’s great, but the script could use a bit more life

    Humans

    22 February 2023

    By Simon Ings
    Teddy (Rahul Kohli) contronts his father (Marcelo Tubert)Magnet releasing
    Next Exit
    Mali Elfman
    Apple TV
    FROM out of nowhere, a chink of light appears. With painful slowness, it grows stronger: we are inching towards a half-open door. Beyond the door, everything seems normal. A little boy plays a game of pretend. At least, that is what we think. Soon enough we learn what is really going on: he is playing cards with his dead father.
    Nothing else in Mali Elfman’s debut feature lives up to this unsettling opening, though there is a … More

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    Was the shift to farming really the worst mistake in human history?

    The notion that our ancestors’ shift from a hunter-gatherer lifestyle to farming was disastrous for our health is well established, but a new study should prompt a rethink, says Michael Marshall

    Humans

    | Columnist

    22 February 2023

    By Michael Marshall
    Shutterstock/J. Lekavicius
    This is an extract from the Our Human Story email newsletter. Sign up to receive it for free in your inbox every month.
    STOP me if you have heard this one before: the transition to farming was a cataclysmic turn for the worse. Beginning around 12,000 years ago, some of our ancestors started cultivating crops, abandoning the egalitarian and sustainable hunter-gatherer lifestyle that had worked for hundreds of thousands of years. The result was poor health, limited diets, new diseases and unsustainable practices that have culminated with climate change and a sixth mass extinction.
    This narrative has become well … More

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    How to use the science of fat to make delicious, confit food

    Fat gets a bad rap, but it is key to making enjoyable foods like confit pork. You can also use the confit method for parsnips, says Sam Wong

    Humans

    22 February 2023

    By Sam Wong
    PhotoCuisine/Viel, Pierre Louis/StockFood
    FAT is a controversial subject in food science. We have all been told from an early age that it is unhealthy and something we should try to eat less of. But as we have said in New Scientist before, the science that led us to fear it is deeply flawed, and many studies have found that cutting down on fat brings no clear health benefits.
    In fact, fats are an essential part of our diet, a vital aid to cooking and key to what makes many of our favourite foods, such as chocolate, so enjoyable. To make smarter … More