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    Porvenir massacre: Did US army have larger role in 1918 killings?

    By Kismat Shrees
    The first archaeological survey of the site of Porvenir, where a century-old massacre occurred at the US-Mexico border, has discovered bullets and cartridge casings for US military weapons.
    A ballistics analysis has raised new questions about the role of the US Army in the 1918 Porvenir massacre, where Texas Rangers killed 15 unarmed Mexican boys and men. The new evidence collected by David Keller, an archaeologist at Sul Ross State University in Texas, and colleagues suggest the US army could have played a bigger role in the massacre than previously thought.

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    Don’t Miss: The way of water, first of four sequels to Avatar

    Spotlight on plankton, the ocean’s fascinating, bite-sized creaturesEvery night, plankton take a journey to shallower waters to feed, prompting predators to follow in search of a very small, but tasty, snack. These images are taken from a new book, Planktonia, illuminating their daily ascent More

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    The science of self-knowledge is important, even if it is a bit fuzzy

    Who you really are is a major question worth pursuing for most people, so research into self-knowledge is important despite the fact it often relies on subjective findings

    Humans

    | Leader

    7 December 2022

    Eugenio Marongiu/Cultura Creative RF/Alamy
    WHO am I? It is a simple yet profound question, long considered worth grappling with on the basis that self-knowledge is good. Take personality, for instance. Intuitively at least, it makes sense to think that if you know your personality, you will make wiser life decisions, have better relationships and ultimately enjoy greater well-being.
    That may be true, but studying how accurately we perceive our personality, the subject of our cover story Self-knowledge: How to know your true personality and why it matters, is fraught with difficulties. The fact is there is no objective perspective on your personality in … More

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    Homo Sapiens Rediscovered review: Hunting human origin stories

    From a bone fragment of a mysterious new species to the latest on cave art, Paul Pettit’s powerful new book shows how science is rewriting the past

    Humans

    7 December 2022

    By Alison George
    Upper Palaeolithic art on a replica of the Chauvet cave, south-east FranceAndiA/Alamy
    Homo Sapiens Rediscovered
    Paul Pettitt (Thames & Hudson)
    WHO are we? This fundamental question has always exercised humanity. One way to approach it is to look at our origins and the evolutionary journey we have taken. Today, thanks to powerful new tools, we can look at the lives of our ancestors in unprecedented detail: the meals they ate, their relationships. And through their art and other practices, we can even get hints about their beliefs about the world.
    Paul Pettitt, … More

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    A bizarre gamma-ray burst breaks the rules for these cosmic eruptions

    Astronomers have spotted a bright gamma-ray burst that upends previous theories of how these energetic cosmic eruptions occur.

    For decades, astronomers thought that GRBs came in two flavors, long and short — that is, lasting longer than two seconds or winking out more quickly. Each type has been linked to different cosmic events. But about a year ago, two NASA space telescopes caught a short GRB in long GRB’s clothing: It lasted a long time but originated from a short GRB source.

    “We had this black-and-white vision of the universe,” says astrophysicist Eleonora Troja of the Tor Vergata University of Rome. “This is the red flag that tells us, nope, it’s not. Surprise!”

    This burst, called GRB 211211A, is the first that unambiguously breaks the binary, Troja and others report December 7 in five papers in Nature and Nature Astronomy.

    Prior to the discovery of this burst, astronomers mostly thought that there were just two ways to produce a GRB. The collapse of a massive star just before it explodes in a supernova could make a long gamma-ray burst, lasting more than two seconds (SN: 10/28/22). Or a pair of dense stellar corpses called neutron stars could collide, merge and form a new black hole, releasing a short gamma-ray burst of two seconds or less.

    But there had been some outliers. A surprisingly short GRB in 2020 seemed to come from a massive star’s implosion (SN: 8/2/21). And some long-duration GRBs dating back to 2006 lacked a supernova after the fact, raising questions about their origins.

    “We always knew there was an overlap,” says astrophysicist Chryssa Kouveliotou of George Washington University in Washington, D.C., who wrote the 1993 paper that introduced the two GRB categories, but was not involved in the new work. “There were some outliers which we did not know how to interpret.”

    There’s no such mystery about GRB 211211A: The burst lasted more than 50 seconds and was clearly accompanied by a kilonova, the characteristic glow of new elements being forged after a neutron star smashup.

    This shows the glow of a kilonova that followed the oddball gamma-ray burst called GRB 211211A, in images from the Gemini North telescope and the Hubble Space Telescope.M. Zamani/International Gemini Observatory/NOIRLab/NSF/AURA, NASA, ESA

    “Although we suspected it was possible that extended emission GRBs were mergers … this is the first confirmation,” says astrophysicist Benjamin Gompertz of the University of Birmingham in England, who describes observations of the burst in Nature Astronomy. “It has the kilonova, which is the smoking gun.”

    NASA’s Swift and Fermi space telescopes detected the explosion on December 11, 2021, in a galaxy about 1.1 billion light-years away. “We thought it was a run-of-the-mill long gamma-ray burst,” says astrophysicist Wen-fai Fong of Northwestern University in Evanston, Ill.

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    It was relatively close by, as GRBs go. So that allowed Fong’s and Troja’s research groups to independently continue closely observing the burst in great detail using telescopes on the ground, the teams report in Nature.

    As the weeks wore on and no supernova appeared, the researchers grew confused. Their observations revealed that whatever had made the GRB had also emitted much more optical and infrared light than is typical for the source of a long GRB.

    After ruling out other explanations, Troja and colleagues compared the burst’s aftereffects with the first kilonova ever observed in concert with ripples in spacetime called gravitational waves (SN: 10/16/17). The match was nearly perfect. “That’s when many people got convinced we were talking about a kilonova,” she says.

    In retrospect, it feels obvious that it was a kilonova, Troja says. But in the moment, it felt as impossible as seeing a lion in the Arctic. “It looks like a lion, it roars like a lion, but it shouldn’t be here, so it cannot be,” she says. “That’s exactly what we felt.”

    Now the question is, what happened? Typically, merging neutron stars collapse into a black hole almost immediately. The gamma rays come from material that is superheated as it falls into the black hole, but the material is scant, and the black hole gobbles it up within two seconds. So how did GRB 211211A keep its light going for almost a minute?

    It’s possible that the neutron stars first merged into a single, larger neutron star, which briefly resisted the pressure to collapse into a black hole. That has implications for the fundamental physics that describes how difficult it is to crush neutrons into a black hole, Gompertz says.

    Another possibility is that a neutron star collided with a small black hole, about five times the mass of the sun, instead of another neutron star. And the process of the black hole eating the neutron star took longer.

    Or it could have been something else entirely: a neutron star merging with a white dwarf, astrophysicist Bing Zhang of the University of Nevada, Las Vegas and colleagues suggest in Nature. “We suggest a third type of progenitor, something very different from the previous two types,” he says.

    White dwarfs are the remnants of smaller stars like the sun, and are not as dense or compact as neutron stars. A collision between a white dwarf and a neutron star could still produce a kilonova if the white dwarf is very heavy.

    The resulting object could be a highly magnetized neutron star called a magnetar (SN: 12/1/20). The magnetar could have continued pumping energy into gamma rays and other wavelengths of light, extending the life of the burst, Zhang says.

    Whatever its origins, GRB 211211A is a big deal for physics. “It is important because we wanted to understand, what on Earth are these events?” Kouveliotou says.

    Figuring out what caused it could illuminate how heavy elements in the universe form. And some previously seen long GRBs that scientists thought were from supernovas might actually be actually from mergers.

    To learn more, scientists need to find more of these binary-busting GRBs, plus observations of gravitational waves at the same time. Trejo thinks they’ll be able to get that when the Laser Interferometer Gravitational-Wave Observatory, or LIGO, comes back online in 2023.

    “I hope that LIGO will produce some evidence,” Kouveliotou says. “Nature might be graceful and give us a couple of these events with gravitational wave counterparts, and maybe [help us] understand what’s going on.” More

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    Self-knowledge: How to know your true personality and why it matters

    When it comes to knowing yourself, your own perception of your personality doesn’t necessarily align with that of people around you. But which is more accurate? And can discovering your true nature lead to a better life?

    Humans

    7 December 2022

    By Daniel Cossins
    Jason Ford
    EVER wondered what other people think of you – I mean, what they really think of you? I consider myself decent company, for instance, even if I know I get a bit vociferous after a few pints of bitter. I like to think I am open-minded and considerate, too, though I recognise I can be dismissive at times. But lately, particularly the morning after a few of those pints, I have become curious about how other people see me.
    Let’s be honest: sometimes I wonder if people think I’m more obnoxious than I realise. Because presumably you wouldn’t know. That is partly where the intrigue lies for me. How accurately do we see ourselves? And who is the real you anyway – the person you think you are, or the person other people see?
    It isn’t that I am self-obsessed, you understand. I am just intrigued about the extent to which the way people see my personality tallies with the way I view myself. Ultimately, I wonder whether being more aware of these shadowy hinterlands of self-knowledge might make life better – not only for me, but for those who spend time with me. Did I say I wasn’t self-obsessed?
    In search of answers, I did what most sensible people tend to avoid: I solicited honest insights into my nature from a dozen friends, family members and colleagues. I asked them to fill out a 60-point questionnaire designed by psychologists to assess personality, and to give the two traits they most associate with me – one positive and one negative. Then I waited nervously for the scales to fall from my eyes.
    Personality test … More

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    In 2022, the James Webb Space Telescope brought us new views of the cosmos

    This year marked the end of a decades-long wait for astronomers. The James Webb Space Telescope is finally in action.

    The telescope, which launched in December 2021, released its first science data in July (SN: 8/13/22, p. 30) and immediately began surpassing astronomers’ expectations.

    “We’ve realized that James Webb is 10 times more sensitive than we predicted” for some kinds of observations, says astronomer Sasha Hinkley of the University of Exeter in England. His team released in September the telescope’s first direct image of an exoplanet (SN: 9/24/22, p. 6). He credits “the people who worked so hard to get this right, to launch something the size of a tennis court into space on a rocket and get this sensitive machinery to work perfectly. And I feel incredibly lucky to be the beneficiary of this.”

    The telescope, also known as JWST, was designed to see further back into the history of the cosmos than ever before (SN: 10/9/21 & 10/23/21, p. 26). It’s bigger and more sensitive than its predecessor, the Hubble Space Telescope. And because it looks in much longer wavelengths of light, JWST can observe distant and veiled objects that were previously hidden.

    JWST spent its first several months collecting “early-release” science data, observations that test the different ways the telescope can see. “It is a very, very new instrument,” says Lamiya Mowla, an astronomer at the University of Toronto. “It will take some time before we can characterize all the different observation modes of all four instruments that are on board.”

    That need for testing plus the excitement has led to some confusion for astronomers in these heady early days. Data from the telescope had been in such high demand that the operators hadn’t yet calibrated all the detectors before releasing data. The JWST team is providing calibration information so researchers can properly analyze the data. “We knew calibration issues were going to happen,” Mowla says.

    The raw numbers that scientists have pulled out of some of the initial images may end up being revised slightly. But the pictures themselves are real and reliable, even though it takes some artistry to translate the telescope’s infrared data into colorful visible light (SN: 3/17/18, p. 4).

    The stunning photos that follow are a few of the early greatest hits from the shiny new observatory.

    Deep space

    NASA, ESA, CSA, STScI

    JWST has captured the deepest views yet of the universe (above). Galaxy cluster SMACS 0723 (bluer galaxies) is 4.6 billion light-years from Earth. It acts as a giant cosmic lens, letting JWST zoom in on thousands of even more distant galaxies that shone 13 billion years ago (the redder, more stretched galaxies). The far-off galaxies look different in the mid-infrared light (above left) captured by the telescope’s MIRI instrument than they do in the near-infrared light (above right) captured by NIRCam. The first tracks dust; the second, starlight. Early galaxies have stars but very little dust.

    Rings around Neptune

    NASA, ESA, CSA, STSCI; IMAGE PROCESSING: JOSEPH DEPASQUALE/STSCI, NAOMI ROWE-GURNEY/NASA GODDARD SPACE FLIGHT CENTER

    JWST was built to peer over vast cosmic distances, but it also provides new glimpses at our solar system neighbors. This pic of Neptune was the first close look at its delicate-looking rings in over 30 years (SN: 11/5/22, p. 5).

    Under pressure

    NASA, ESA, CSA, STScI, JPL-Caltech/NASA

    The rings in this astonishing image are not an optical illusion. They’re made of dust, and a new ring is added every eight years when the two stars in the center of the image come close to each other. One of the stars is a Wolf-Rayet star, which is in the final stages of its life and puffing out dust. The cyclical dusty eruptions allowed scientists to directly measure for the first time how pressure from starlight pushes dust around (SN: 11/19/22, p. 6).

    Galaxy hit-and-run

    NASA James Webb Space Telescope/Flickr (CC BY 2.0)

    With JWST’s unprecedented sensitivity, astronomers plan to compare the earliest galaxies with more modern galaxies to figure out how galaxies grow and evolve. This galactic smashup, whose main remnant is known as the Cartwheel galaxy, shows a step in that epic process (SN Online: 8/3/22). The large central galaxy (right in the above composite) has been pierced through the middle by a smaller one that fled the scene (not in view). The Hubble Space Telescope previously snapped a visible light image of the scene (top half). But with its infrared eyes, JWST has revealed much more structure and complexity in the galaxy’s interior (bottom half).

    Exoplanet portrait

    NASA, ESA, CSA, Aarynn Carter/UCSC, The ERS 1386 Team, Alyssa Pagan/STSCI

    The gas giant HIP 65426b was the first exoplanet to have its portrait taken by JWST (each inset shows the planet in a different wavelength of light; the star symbol shows the location of the planet’s parent star). This image, released by astronomer Sasha Hinkley and colleagues, doesn’t look like much compared with some of the other spectacular space vistas from JWST. But it will give clues to what the planet’s atmosphere is made of and shows the telescope’s potential for doing more of this sort of work on even smaller, rocky exoplanets (SN: 9/24/22, p. 6).

    Shake the dust off

    NASA, ESA, CSA, STScI, Hubble Heritage Project/STScI/AURA; Image Processing: Joseph DePasquale, Anton M. Koekemoer and Alyssa Pagan/STScI

    Another classic Hubble image updated by JWST is the Pillars of Creation. When Hubble viewed this star-forming region in visible light, it was shrouded by dust (above left). JWST’s infrared vision reveals sparkling newborn stars (above right). More

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    Homo naledi may have used fire to cook and navigate 230,000 years ago

    By Alison George
    A reconstruction of the skull of a Homo naledi childBrett Eloff Photography
    Archaeological evidence suggests that Homo naledi, a primitive human species with a chimpanzee-like skull, used fires to cook food and navigate in the darkness of underground caves, despite having a brain one third of the size of ours.
    “We have massive evidence. It’s everywhere,” says Lee Berger at the University of the Witwatersrand in South Africa. “Huge lumps of charcoal, thousands of burned bones, giant hearths and baked clay.”
    This find, which is still being analysed and remains controversial, could revolutionise our understanding of the emergence of complex behaviours that had been thought to be the sole domain of large-brained species, such as modern humans and Neanderthals.Advertisement
    H. naledi was first discovered in 2013 in the Rising Star cave system in South Africa when two cavers managed to enter a hitherto unexplored chamber via an incredibly tight passage. The surface was littered with thousands of fossil bones. In 2015, these were declared to belong to a new species.
    We now know that H. naledi was about 144 centimetres tall on average and weighed around 40 kilograms. It had a strange mix of primitive and modern features, with ape-like shoulders, a tiny brain only just bigger than that of a chimpanzee and teeth “more reminiscent of something millions of years old”, says Berger.
    Yet dating of its fossil remains in 2017 showed that it lived relatively recently, between 230,000 to 330,00 years ago, meaning that it could have co-existed with Homo sapiens, which evolved in Africa around 300,000 years ago.
    A hearth possibly made by Homo nalediLee Berger
    But questions remained about how H. naledi navigated through the labyrinth of underground passages at Rising Star, which are in complete darkness and require complex manoeuvres through gaps in the rock just 17.5 centimetres wide.
    This inaccessibility means that, in the past decade, only 47 people – all small and slightly built – had managed to access the Dinaledi chamber where H. naledi fossils were first discovered. But in August this year, Berger, who is 188cm tall, decided to risk entering this labyrinth, losing 25 kilograms of weight in preparation.
    “It’s not a space made for six-feet-two people like me. I’m by far the largest person who’s even been in,” he says. He knew there was a possibility he might not be able to squeeze out again. “I almost died on the way out,” he says.
    The risk paid off. When Berger entered the Dinaledi chamber and looked up, he realised that there were blackened areas and soot particles on the rock. “The entire roof of the chamber is burnt and blackened,” he says.
    By coincidence, at the same time that Berger was observing the soot, his colleague Keneiloe Molopyane, also at the University of the Witwatersrand, uncovered a tiny hearth with burnt antelope bones in another part of the cave system, then a large hearth next to it 15cm below the cave floor. Then, in another area called the Lesedi chamber, Berger found a stack of burnt rocks, with a base of ash and burnt bones.
    This is a remarkable discovery, as many researchers thought it was impossible for such a small-brained hominin to make and use fire within a cave system. Although we have evidence that ancient humans living in what is now Kenya could control fire as far back as 1.5 million years ago, this capacity “is typically associated with larger-brained Homo erectus”, says Berger.
    H. naledi also seem to have used the space in interesting ways, with “body disposal in one space and cooking of animals in adjacent spaces”, says Berger. “The capacity to make and use fire finally shows us how Homo naledi ventured so deep into dangerous spaces, and explains how they may have moved their dead kin into such spaces, something likely impossible without light. It also hints at a complex naledi culture becoming visible to us.”

    Dating of the charred remains is still underway, so the decision to announce the fire discovery in a talk on 1 December, prior to the publication of the formal scientific analysis, has proved controversial.
    “It’s impossible to evaluate Lee Berger’s claims properly without seeing the full evidence, but apparently that is forthcoming,” says Chris Stringer at the Natural History Museum in London. “With all due respect to Lee and his teams for a series of great finds, this is not the way to conduct science or progress scientific debate about potentially very important discoveries.”
    However, for Francesco d’Errico at the University of Bordeaux in France, the discovery that H. naledi may have been able to control fire could give insight into the way they treated their dead and their social organisation.
    “If Homo naledi were shown to have mastered fire and used it to gain access to the most remote areas of the Rising Star karst system, this could have very important implications for the interpretation of mortuary practices conducted at the site,” he says. “The control of an artificial light source allows the organisation of actions in space and time and, in the case of mortuary practices, facilitates the participation of several members of the group in collaborative and shared actions.”
    Charcoal possibly used by Homo nalediLee Berger
    For Berger, the fire-use discovery has implications that are even more revolutionary. If these small-brained humans with many primitive features were capable of the complex cognition required to make and control fire, then “we’re beginning to see the emergence of a cultural pathway and behaviour that we thought, until this moment, was the domain of [Homo sapiens and Neanderthals],” he says.
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