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    The World Engines series reveals the high cost of conquering space

    What do we risk by expanding recklessly into the multiverse? Stephen Baxter’s World Engines series is gripping but frustrating, says Sally Adee

    Humans 19 August 2020
    By Sally Adee
    Why do we risk so much in the hope of colonising space?
    Gorodenkoff/Getty Images

    REID MALENFANT wakes up from a cryogenic coma in the year 2469. It was 2019 when he crashed a space shuttle and entered medical deep freeze, just as Earth’s citizens were taking their first steps to colonise the solar system. The world he wakes in 450 years later is unrecognisable. We burned all our fossil fuels for the space race and the consequences are in full bloom: London, New York, Florida and many coastal areas are drowned, and the planet is tropical.
    Those are just the cosmetic changes in World Engines: Destroyer, the first in Stephen Baxter’s series. The human project has ended – we retreated from the solar system, recognising our inability to thrive outside our biosphere. We retreated on Earth too, with a population fallen below 100 million, both as a result of centuries-long destruction and as a way to let nature heal.
    As Malenfant digs deeper, though, he discovers another contributing factor. A solar system-rending cataclysm has been foreseen in about 1000 years, so Earth is in a period of managed decline. It isn’t a bad existence for the people. There is no pollution and no waste, with every car, cup and plate made to last generations. Universal basic income (UBI) means no one is poor. People still have children. But there is no drive to do more than exist in this Eden.
    “In one universe, Richard Nixon created a Star Trek-like programme that had boots on Mars by 2005”
    Yet the 25th century woke up Malenfant for a reason, of course. That reason takes him to the Martian moon Phobos, which has been displaying idiosyncracies that turn out to be a hatch to other universes. By the end of the first book, Malenfant has set out to discover who built the portal and what kind of entities play snooker with entire solar systems.
    It is these questions that are addressed in the second book, World Engines: Creator, and their answers leave deeper questions about humanity’s relentless obsession with expansion. What do we risk by embarking recklessly into the solar system, the universe or even the multiverse? What is this impulse to colonise? Are the only choices eternal expansion or managed decline?
    Many readers may have given up on the first book after some 200 pages because of Malenfant, a jerk ripped straight from the pages of 1960s sci-fi at its most toxically masculine. But the clue is in the name. Soldier on and it is clear that Baxter has written Malenfant to reflect our current condition as a species: selfish, greedy and full of toxic individualism.
    As Malenfant begins to evolve, the books hit their stride, asking questions that telescope out into brain-exploding territory. Baxter has an encyclopedic knowledge of early space and military history that he remixes into delightful mash-ups. In one universe, instead of sinking in the Watergate scandal, US president Richard Nixon set up UBI, leading the world to follow suit – and to the creation of a Star Trek-like space programme that had boots on Mars by 2005.

    In another, Winston Churchill is ousted by his opposition rival, Neville Chamberlain. This creates a British-led dominance of space in steampunk space behemoths, spreading diamond-cut accents and Victorian repression.
    Other books have grappled with our place in the multiverse, but few have Baxter’s vision and ability to work at very different scales. World Engines: Creator isn’t always evenly paced, gets bogged down in science pedantry and can be exasperatingly opaque at times, but I am crossing my fingers for a third book.

    Sally also recommends…
    Book/Comic
    The Space Between Worlds
    Micaiah Johnson’s stunning debut is impossible to put down. It nails the stakes of the multiverse and employs a beautiful character transformation arc.
    The Number of the Beast
    Robert A. Heinlein’s book is the first and best in this genre.
    Infinite Vacation
    Nick Spencer’s comic world puts alternate versions of you up for sale. You choose the version you prefer that day, but there is always a price.

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    Fukushima surfers return nearly a decade after the nuclear disaster

    While keen surfers take to the waves around Fukushima, plans are under way to dump contaminated water from the damaged nuclear power plant into the sea

    Humans 19 August 2020
    By Gege Li

    Laura Liverani

    PhotographerLaura Liverani
    Agency Prospekt Photographers

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    THIS surfer is one of many hoping to catch the waves at Kitaizumi beach in Japan’s Fukushima prefecture. The coastal spot was once hailed as a surfer’s paradise thanks to its high waves and sandy shores. Yet it has been almost a decade since it has been able to enjoy that status.
    In 2011, the Fukushima Daiichi nuclear power plant – situated around 25 kilometres from the beach – was the site of the worst nuclear accident since the Chernobyl disaster in 1986, after it was hit by a devastating tsunami. Kitaizumi reopened to the public in 2019 after a huge decontamination effort, and surfers are keen to see people return to the beach.
    Taken by photographer Laura Liverani as part of a series called Fukushima Surfers, the image shows how the sport is making a comeback in the area. Though the building in the background is the Haramachi coal power station, not Fukushima Daiichi, the legacy of the nuclear plant still lingers.
    Due to a lack of space, Japan plans to tip 1 million tonnes of contaminated water stored from the disaster – a combination of recovered groundwater and deliberately injected cooling waters – into the Pacific Ocean after it is treated. Managed properly, this shouldn’t release any harmful radioactive particles that could pass into marine sediment and fish or threaten surfers’ safe return to the sea.
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    In a first, astronomers spotted a space rock turning into a comet

    Like the mythical half-human, half-horse creatures, centaurs in the solar system are hybrids between asteroids and comets. Now, astronomers have caught one morphing from one type of space rock to the other, potentially giving scientists an unprecedented chance to watch a comet form in real time in the decades to come.
    “We have an opportunity here to see the birth of a comet as it starts to become active,” says planetary scientist Kat Volk of the University of Arizona in Tucson.
    The object, called P/2019 LD2, was discovered by the ATLAS telescope in Hawaii in May. Its orbit suggests that it’s a centaur, a class of rocky and icy objects with unstable orbits. Because of that mixed composition and potential to move around the solar system, astronomers have long suspected that centaurs are a missing link between small icy bodies in the Kuiper Belt beyond Neptune and comets that regularly visit the inner solar system (SN: 11/19/94).
    These “short-period” comets, which are thought to originate from icy objects in the Kuiper Belt, orbit the sun once a decade or so, and make repeat appearances in Earth’s skies. (Long-period comets, like Halley’s Comet, which visits the inner solar system once a century, probably originate even farther from the sun, in the Oort cloud (SN: 10/25/13).)

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    All previously found short-period comets were spotted only after they had transitioned into comets (SN: 8/6/14). But LD2 just came in from the Kuiper Belt recently and will become a comet in as little as 43 years, Volk and colleagues report August 10 at arXiv.org.
    “It’s weird to think that this object should be becoming a comet when I’m retiring,” Volk says.
    In 2019, she and colleagues showed that there’s a region of space just beyond Jupiter that they call the “Gateway”.  In this area, small planetary objects hang out while warming up and transitioning from outer solar system ice balls to inner solar system comets with their long tails. It’s like a comet incubator, says planetary scientist Gal Sarid of the SETI Institute, who is based in Rockville, Md.
    After hearing about LD2, Volk, Sarid and their colleagues simulated thousands of possible trajectories to see where the object had been and where it is going. LD2’s orbit probably took it near Saturn around 1850, and it entered its current orbit past Jupiter after a close encounter with the gas giant in 2017, the team found. The object will leave its present orbit and move in toward the sun in 2063, where heat from the sun will probably sublimate LD2’s volatile elements, giving it a bright cometary tail, the researchers say.
    “This will be the first ever comet that we know its history, because we’ve seen it before being a comet,” Sarid says.
    The fact that LD2 is fairly new to the inner reaches of the solar system suggests that it’s made of relatively pristine material that has been in the back of the solar system’s freezer for billions of years, unaltered by heat from the sun. That would make it a time capsule of the early solar system. Studying its composition could help planetary scientists learn what the first planets were made of.
    The orbital analysis looks “very reasonable,” says Henry Hsieh, a planetary astronomer with the Planetary Science Institute who is based in Honolulu and was not involved in the study. But studying just one transition object is not enough to open the solar system time capsule.
    “What we really need to do is study many of these,” he says. “Study this one first, and then study more of them, and figure out whether this object is an outlier or whether we see a consistent picture.” Future sky surveys, like the ones planned using the future Vera Rubin Observatory (SN: 1/10/20), should discover more balls of ice shifting into comets.
    Sarid and colleagues think LD2 could be a good target for a spacecraft to visit. NASA has considered sending spacecraft to centaurs, although no missions have been selected for development yet. But considering that LD2 will become a comet in just a few decades, scientists don’t have much time to plan, build and launch a mission to visit it. “The windows are closing,” Sarid says. “We really need to be doing this now.” More

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    Hubble watched a lunar eclipse to see Earth from an alien’s perspective

    To practice searching for extraterrestrial life, researchers have run a dress rehearsal with the one world they know to be habitable: Earth.
    While Earth was between the sun and moon for a lunar eclipse in January 2019, the Hubble Space Telescope observed how chemicals in Earth’s atmosphere blocked certain wavelengths of sunlight from reaching the moon. That observing setup mimicked the way astronomers plan to probe the atmospheres of Earthlike exoplanets as they pass in front of their stars, filtering out some starlight.
    “We basically pretend we’re alien observers looking at our planet,” says Giada Arney, a planetary scientist at NASA’s Goddard Space Flight Center in Greenbelt, Md.
    Using Hubble, the researchers focused on spotting the effects of atmospheric ozone. Because ozone is both a chemical by-product of oxygen produced in photosynthesis and a shield that protects life from the sun’s harmful ultraviolet rays, astronomers think atmospheric ozone could be a key indicator that a distant world is habitable. During the lunar eclipse, Hubble examined sunlight that had passed through Earth’s atmosphere and reflected off of the moon for signatures of ozone.

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    “It’s safer for Hubble to observe sunlight reflected off the moon” than to look directly at the backlit Earth, explains Allison Youngblood, an astronomer at the University of Colorado Boulder. The telescope’s instruments are so sensitive and Earth is so bright that “even the nightside would fry Hubble’s detectors.” 
    Those observations revealed prominent dips in particular wavelengths of ultraviolet sunlight that had been absorbed by the ozone, Youngblood, Arney and colleagues report online August 6 in the Astronomical Journal.
    The data help confirm that chemicals in the Earth’s atmosphere filter light as expected, based on researchers’ understanding of atmospheric chemistry. That finding gives astronomers more confidence that they will be able to recognize potentially habitable exoplanets. More

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    Earliest known beds are 227,000-year-old piles of grass and ash

    By Michael Le Page
    The Border cave in South Africa
    A. Kruger

    People living in the Border cave in southern Africa slept on grass bedding 227,000 years ago – by far the oldest discovery of its kind.
    “That’s quite close to the origin of our species,” says Lyn Wadley at the University of the Witwatersrand in Johannesburg, South Africa.
    Her team has been excavating Border cave in the province of KwaZulu-Natal, which was inhabited on and off during prehistory. The peoples who lived there left many layers of deposits that have been preserved by the very dry conditions.

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    Wadley’s team has found grass bedding in many of these layers, made from several species including Panicum maximum, which still grows outside the cave. The oldest layers containing the bedding are between 227,000 and 183,000 years old.
    This grass bedding was often on top of ash layers. In some places these ashes are of burned grasses, suggesting people burned their old, pest-infested bedding and placed new bedding on top.

    In other places, the ashes are of burned wood, suggesting ashes from wood fires were spread out and grass placed on top. This means people were deliberately putting grass bedding on ashes to deter crawling insects, says Wadley.
    The team also found burned bits of camphor wood – camphor is still used as an insect repellent today. “Maybe it was burned for the smoke it creates that would repel flying insects,” says Wadley.
    She has no doubt that the grasses were used for bedding. They are found only towards the sheltered rear of the cave, and often near to fireplaces. In fact, sometimes the edges of the bedding are singed.

    Shards of rock mixed in with some bedding suggest people sat on the bedding as they made stone tools.
    There are even bits of ochre powder in the bedding that might have rubbed off people’s skin as they slept. However, there is ochre in the roof of the cave, so the team cannot be sure it didn’t fall from the roof.
    Before this discovery, the oldest-known bedding was 77,000 years old. Wadley found it at Sibudu cave, also in KwaZulu-Natal.

    Her team has also found evidence of people roasting vegetables as long ago as 170,000 years. “If you want to get to the nitty-gritty of everyday life, look at plants,” says Wadley.
    Her team presumes the people living in Border cave 227,000 years ago were modern humans – Homo sapiens – but cannot be sure it wasn’t another species such as Homo naledi.
    Journal reference: Science, DOI: 10.1126/science.abc7239

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    Stone Age people were cremating their dead about 9000 years ago

    By Michael Marshall
    These cremated bones are 9000 years old
    Bocquentin et al, 2020 (PLOS ONE, CC BY)

    Stone Age people were cremating their dead in fire pits about 9000 years ago, in what is now Israel. The development of cremation may have been linked to a shift in their religious beliefs, away from worship of ancestors.
    For tens of thousands of years, people tended to bury their dead, says Fanny Bocquentin at the French National Centre for Scientific Research in Paris. There is also evidence that Neanderthals buried their dead about 70,000 years ago. Cremation, in which the body is intentionally burned, is a relatively recent invention.
    Bocquentin and her colleagues have excavated a Stone Age village called Beisamoun in Israel. It was occupied between at least 7200 and 6400 BC.

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    During the dig, they discovered a U-shaped pit, 80 centimetres across and 60 centimetres deep. The sides of the pit had been plastered with wet mud, similar to that used elsewhere in the village to make mud bricks. In the middle of the pit, the team found a large quantity of ash, which contained 355 fragments of charred human bone.
    The bones all seem to belong to one individual: a young adult, whose sex couldn’t be determined. The remains have been dated to between 7030 and 6700 BC.

    It isn’t clear how the person died. There was a projectile point embedded in the left shoulder blade, indicating the person had been injured, but this had healed. “It was a clean wound, no infection,” says Bocquentin.
    The ash was the remains of wood that had been stacked into a pyre and burned. It isn’t clear if the body was on top of the pyre, inside it or under it.
    Previous burial practices were occasionally elaborate. In some instances, people would bury a body, then they would return, dig it up and remove the skull – which they reburied in a new pit with other skulls. Sometimes they plastered the skull with lime plaster or mud, creating a new face. “It’s long funeral practices in several steps,” says Bocquentin. “You are taking care of the dead for a long period of time.” In the Stone Age village of Çatalhöyük in Turkey, bodies were buried under the floors of houses. This all indicates a reverence for ancestors and a desire to be close to them, says Bocquentin.

    Cremation is much faster, says Bocquentin. “You don’t wait even for the decay process.”
    This could reflect a shift in religious beliefs, suggests Bocquentin. “I would say the status of the dead and the relation between dead and living is totally different,” she says. “We might think that there are new beliefs, maybe that the dead are not as important as they were, and maybe a new kind of god appearing.”
    The Beisamoun cremation is the oldest in south-west Asia, but not the oldest in the world. For instance, archaeologists have found the cremated remains of a child from 11,500 years ago in Alaska. It isn’t clear how many times cremation was independently invented, says Bocquentin.
    Journal reference: PLoS One , DOI: 10.1371/journal.pone.0235386
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    Coded Bias review: An eye-opening account of the dangers of AI

    Computers are worse at recognising women and people of colour than white men. Documentary Coded Bias shows that the problems don’t stop there

    Technology 12 August 2020
    By Vijaysree Venkatraman
    Face-recognition AI could only “see” Joy Buolamwini when she wore a white mask
    7th Empire Media

    Coded Bias
    Shalini Kantayya
    Ongoing film festival screenings

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    IN HER first semester as a graduate student at the MIT Media Lab, Joy Buolamwini encountered a peculiar problem. Commercial face-recognition software, which detected her light-skinned classmates just fine, couldn’t “see” her face. Until, that is, she donned a white plastic mask in frustration.
    Coded Bias is a timely, thought-provoking documentary from director Shalini Kantayya. It follows Buolamwini’s journey to uncover racial and sexist bias in face-recognition software and other artificial intelligence systems. Such technology is increasingly used to make important decisions, but many of the algorithms are a black box.
    “I hope this will be a kind of Inconvenient Truth of algorithmic justice, a film that explains the science and ethics around an issue of critical importance to the future of humanity,” Kantayya told New Scientist.
    The documentary, which premiered at the Sundance Film Festival earlier this year, sees a band of articulate scientists, scholars and authors do most of the talking. This cast primarily consists of women of colour, which is fitting because studies, including those by Buolamwini, reveal that face-recognition systems have much lower accuracy rates when identifying female and darker-skinned faces compared with white, male faces.
    Recently, there has been a backlash against face recognition. IBM, Amazon and Microsoft have all halted or restricted sales of their technology. US cities, notably Boston and San Francisco, have banned government use of face recognition, recognising problems of racial bias.

    People seem to have different experiences with the technology. The documentary shows a bemused pedestrian in London being fined for partially covering his face while passing a police surveillance van. On the streets of Hangzhou, China, we meet a skateboarder who says she appreciates face recognition’s convenience as it is used to grant her entry to train stations and her residential complex.
    “If an AI suspects you are a gambler, you could be presented with ads for discount fares to Las Vegas”
    The film also explores how decision-making algorithms can be susceptible to bias. In 2014, for example, Amazon developed an experimental tool for screening job applications for technology roles. The tool, which wasn’t designed to be sexist, discounted résumés that mentioned women’s colleges or groups, picking up on the gender imbalance in résumés submitted to the company. The tool was never used to evaluate actual job candidates.
    AI systems can also build up a picture of people as they browse the internet, as the documentary investigates. They can suss out things we don’t disclose, says Zeynep Tufekci at the University of North Carolina at Chapel Hill in the film. Individuals can then be targeted by online advertisers. For instance, if an AI system suspects you are a compulsive gambler, you could be presented with discount fares to Las Vegas, she says.
    In the European Union, the General Data Protection Regulation goes some way to giving people better control over their personal data, but there is no equivalent regulation in the US.
    “Data protection is the unfinished work of the civil rights movement,” said Kantayya. The film argues that society should hold the makers of AI software accountable. It advocates a regulatory body to protect the public from its harms and biases.
    At the end of the film, Buolamwini testifies in front of the US Congress to press the case for regulation. She wants people to support equity, transparency and accountability in the use of AI that governs our lives. She has now founded a group called the Algorithmic Justice League, which tries to highlight these issues.
    Kantayya said she was inspired to make Coded Bias by Buolamwini and other brilliant and badass mathematicians and scientists. It is an eye-opening account of the dangers of invasive surveillance and bias in AI.
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    Don't Miss: Netflix film on dedicating your life to contacting aliens

    J
    Netflix/
    Watch
    John Was Trying to Contact Aliens tells the story of John Shepherd, who spent 30 years trying to contact extraterrestrials by broadcasting music millions of kilometres into space. On Netflix from 20 August.
    Read
    The science transforming the way we learn sees Sanjay Sarma, head of open learning at MIT, join fellow researcher Luke Yoquinto to explain how scientific findings in wildly different fields are transforming the way we learn and teach.
    Visit
    Driverless: who is in control? is an excellent exhibition about autonomous vehicles at London’s Science Museum. The museum reopens on 19 August, and is extending this show until January 2021.
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