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    Physics might create a backdoor to an afterlife – but don't bank on it

    Quantum information can never be destroyed, so some of the essence of you could live on after death – but it’s not going to help the physical you

    Humans 9 December 2020
    By Joshua Howgego
    Is death the end, or does part of us live on?
    Getty Images

    What happens when you die?
    MICHELLE FRANCL-DONNAY will never forget 15 April 1987. Her husband Tom was due to pick her up from an evening meeting, but decided to take a swim first. He had an undiagnosed heart condition, and while in the pool had a catastrophic aneurysm. Michelle rode with him in the ambulance. That was the last time she spoke to him.
    “When I saw Tom’s body the next morning, he clearly wasn’t there anymore,” says Francl-Donnay, a chemist at Bryn Mawr College in Pennsylvania and an adjunct scholar at the Vatican Observatory who writes extensively on both science and spirituality. Over the years, she found herself mulling a question humans have asked for a long time: where had he gone?
    Even those of us who rationally reject the idea of an afterlife have trouble letting go of the idea. That might be down to our theory of mind. Because we habitually put ourselves in other people’s shoes and imagine their thoughts and feelings, it can be hard to believe that those thoughts and feelings can just cease to be when ours still feel so real.
    Yet we have no evidence for anything different. When you die, blood stops flowing, the muscles cool and consciousness, whatever that is, slips away. If your body were simply let be, other organisms would rapidly digest it, from microbes already living inside you to newly arrived blowflies.
    Human burial rites just change the timescale or manner of your physical disappearance: if your remains are cremated, for instance, the … More

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    Why people enjoy alcohol or are teetotal may come down to a hormone

    By Claire Ainsworth

    Matt Cardy/Getty Images

    LARS IGUM RASMUSSEN and his mates were going large. Donning their lederhosen, the three middle-aged men headed into Oktoberfest in Munich, Germany, the world’s biggest folk and beer festival. There, each proceeded to quaff an average of 7.5 litres of beer a day, for three days. It was a spectacular bender.
    Getting hammered wasn’t the main aim of the exercise, however: Rasmussen is health correspondent for Danish magazine Politiken and was writing a story exploring the physiological effects of binge drinking. To understand what was happening to him and his friends, he had enlisted the help of metabolic physiologist Filip Knop at the University of Copenhagen. While Rasmussen was interested in finding out what havoc excessive boozing wreaks on the bodies of middle-aged men, Knop had another motive for getting involved. He and his colleague Matt Gillum had been itching to test a new idea about people’s appetite for alcohol – but couldn’t, in good conscience, solicit anyone to partake in a binge of this magnitude. “It would give the ethics officer a heart attack,” says Gillum. Volunteers, however, were a different matter.
    What Knop and Gillum discovered is helping to build a picture of how our bodies control our boozing habits, from the amount we drink to when we stop. The research is homing in on a hormone that partly explains the huge variation in our social drinking habits: why some people are teetotal or can’t drink much, while others are lushes. It also points to the startling idea that our livers have more say in directing our behaviour than anyone imagined.
    Of course, people choose to … More

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    The Preserve review: The inner struggle to survive in a robot world

    How do humans feel living in a world where robots outperform them, asks The Preserve by Ariel S. Winter. Clare Wilson says it’s a great thought experiment

    Humans 9 December 2020
    By Clare Wilson
    How would we react if machines dominated the world?
    Donald Iain Smith/Getty Images

    The Preserve
    Ariel S. Winter
    Simon & Schuster
    WHEN AI that is truly sentient finally emerges, the big question is how humans will fare. Will machines try to hunt us to extinction, as in the Terminator films, or will their omnipotence mean life for humans can be the kind of extended party of Iain M. Banks’s Culture series?
    In Ariel S. Winter’s The Preserve, the robots have reached a stage somewhere in the middle. The book is set in the not-too-distant future, when human populations have dwindled … More

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    Can you ever know yourself? Whatever the answer, it is worth trying

    Gary Ellis Photography/Alamy
    “KNOW thyself.” The first of three maxims said to have been inscribed in the forecourt of the Temple of Apollo in Delphi sounds grand. What it actually means has been a matter of debate for millennia, and when it comes to knowing ourselves, modern science has made things deliciously more complex, too.
    How the physical substance of our bodies creates our sense of being a consistent entity, and what it means to have that sensation, is a long-standing puzzle. Debates about this relationship between matter and mind were meat and drink to the Ancient Greek philosophers, but … More

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    Ancient humans may have hibernated to survive brutal glacial winters

    By Colin Barras
    Living in darkness, or even hibernating, could have left ancient humans with bone lesions
    gorodenkoff/Getty Images

    Some of the ancient humans living in Europe half a million years ago had a remarkable strategy for dealing with winter: they hibernated. At least, that is the claim being made by two researchers. Others dispute the evidence – but ongoing research suggests that it might be possible to induce a hibernation-like state in modern humans.
    Sima de los Huesos – the “pit of bones” – lies in northern Spain and is one of the world’s most important sites for studying human evolution. Excavations at … More

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    Ancient rock art reveals life of the Amazon’s earliest inhabitants

    By Luke Taylor
    The rock art may be 12,500 years old
    Courtesy of Jose Iriarte

    An extensive collection of ancient rock art and archaeological remains found deep in the Colombian Amazon offers a rare glimpse into the lives of the earliest people to inhabit the region.
    The images and remains suggest that people lived in the northern Amazon at the same time as now-extinct mega-mammals. They also show that the ancient humans had a varied diet, indicating that they adapted quickly to their new environment.
    The as-yet unnamed site in the Serranía La Lindosa, a large, rocky outcrop in southern Colombia, was found by an international team of researchers investigating the Guaviare region. It is the earliest secure evidence of people in the Colombian Amazon, they say.

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    A wealth of Indigenous artwork has been documented across Guaviare, particularly in Chiribiquete National Park. The artwork documented at La Lindosa is new to science, and appears to be unknown even to local people, according to the researchers. It is remarkable in both its detail and its scale, the team says. The collage of images includes geometric patterns, handprints, people and animals. It stretches across approximately 5 kilometres of rock face, and could take decades to fully study.

    The archaeological team – co-led by Francisco Javier Aceituno at the University of Antioquia, Colombia – was thrilled to find depictions of what appear to be now-extinct megafauna alongside more familiar fish, birds and lizards still alive today.
    “We knew that megafauna was in the region and went extinct around 10 to 12,000 years before the present,” says José Iriarte at the University of Exeter, UK, and a member of the research team. If people were depicting them in their art, the humans must have been present in the region at least 12,500 years ago, he argues.
    Iriarte says it is “quite clear” that a palaeolama, an extinct stumpy-legged, long-necked camelid, is depicted. Other drawings have been tentatively identified as giant sloths due to their unique proportions, and mastodons – ancient relatives of elephants – due to their trunks.
    “The realism for South American standards is really impressive,” says Iriarte.

    Others are less sure.
    “The horses are clear,” says Hans ter Steege, an expert on Amazonian plant diversity at the Naturalis Biodiversity Center in the Netherlands, who wasn’t involved in the research. “But the palaeolama could be a poor representation of a deer to me.”
    Further study will be made of the artwork to gain more certainty of the depictions and their age, say the researchers.

    However, additional archaeological evidence makes clear that humans were present in the region 12,500 years ago. The researchers have excavated an area at the base of one section of rock face and uncovered evidence of ancient human activity in the form of processed animal bones. Some of the remains occur in layers of dirt containing charred palms that radiocarbon dating shows are about 12,500 years old. The 12,500-year-old layers also contain fragments of ochre similar to that used to draw the rock art.
    Establishing the presence of humans during this period — in which megafauna roamed the region and the climate was warming — is significant, says Aceituno.
    “The most important thing has been to obtain good radiocarbon dates to specify the early peopling of the area,” he says.
    It shows that humans shared the region with immense beasts, but also helps paint a picture of how their world would have looked.
    No megafauna remains have been found at the site, perhaps suggesting that humans didn’t hunt the animals or they were processed elsewhere. There were no remains of medium-sized animals like monkeys either, a staple food for Indigenous groups inhabiting the region today. “It could mean they had not developed blowgun technology at this stage to hunt prey in the treetops,” says Iriarte.
    Around half the remains were fish — including piranhas — but diets were broad. Reptiles like iguanas and snakes were consumed as well as rodents like paca and capybara.
    There is also evidence that various fruits were eaten. The diversity of animals and plants consumed suggests humans adapted quickly to the Amazon, says ter Steege.
    Journal reference: Quaternary International, DOI: 10.1016/j.quaint.2020.04.026
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    Stone Age humans chose to voyage to Japanese islands over the horizon

    By Donna Lu
    Archaeologists have built replica Stone Age rafts to attempt the crossing to the Ryukyu islands
    Yosuke Kaifu

    Stone Age humans crossed the sea from Taiwan to the Ryukyu islands of south-west Japan tens of thousands of years ago – and it looks like they did so deliberately, even though the islands are too far away to be reliably visible from Taiwan.
    Archaeological sites on several of the Ryukyu islands suggest humans had reached the islands by about 30,000 to 35,000 years ago. Yosuke Kaifu at the University of Tokyo and his colleagues suspect the ancient people did so by travelling north-east from Taiwan – a journey that involved ocean crossings of tens to hundreds of kilometres to hop from island to island. The researchers have even repeated some of these ocean crossings themselves using bamboo rafts of the kind that Stone Age humans might have built.
    But it hadn’t been clear whether the crossing occurred deliberately or by accident. The Kuroshio current, which flows from Luzon in the Philippines past Taiwan and Japan, is one of the strongest ocean currents in the world, and in some parts is 100 kilometres wide.

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    “The speed of the Kuroshio in the east of Taiwan is normally 1 to 2 metres per second,” says Kaifu.

    To find out if people could have arrived at the islands by drifting on this current, the researchers looked at existing data from 138 satellite-tracked buoys, released into the world’s oceans as part of the Global Drifter Program. The 138 buoys all drifted past Taiwan or Luzon between 1989 and 2017.
    Kaifu and his colleagues found that only four buoys travelled to within 20 kilometres of any of the Ryukyu islands. In all four cases this occurred as a result of adverse weather conditions, including a typhoon.
    The finding suggests that the Kuroshio current directs drifters away from, rather than towards, the Ryukyu islands. Because the flow of the current is thought to have stayed the same for the past 100,000 years, it seems likely that Stone Age people reached the Ryukyu islands through deliberate voyaging rather than accidental drifting.
    “Now we can tell with confidence that Palaeolithic people set sail deliberately even to a remote invisible island,” says Kaifu.

    “Most people probably think that Palaeolithic people were just primitive and conservative, but I now see something different from that general image,” he says.
    Journal reference: Scientific Reports, DOI: 10.1038/s41598-020-76831-7
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    Christmas gift ideas: The 13 best science and technology books of 2020

    From The End of Everything by Katie Mack and How to Argue with a Racist by Adam Rutherford to Martha Wells’s Murderbot sc-ifi series, New Scientist’s 2020 gift guide has a book for everyone

    Humans 2 December 2020
    By New Scientist

    Getty Images/Westend61

    The End of Everything (Astrophysically Speaking)
    by Katie Mack
    For a bit of seasonal giving, why not look to the end of the universe? Thankfully, The End of Everything (Scribner) by Katie Mack is no apocalyptic vision but an engrossing and often funny tour of all the ways our cosmos might come to a close. Mack’s enjoyment of physics stands out – and is contagious. She describes primordial black holes as “awfully cute in a terrifying theoretical kind of way”, antimatter as “matter’s annihilation-happy evil twin” and the universe as “frickin’ weird”. All true, and Mack’s explanations … More