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    No, native plants aren't always the best choice for gardens

    There’s a tendency among horticulturists to prefer native plant species, but we shouldn’t assume they are better, writes James Wong

    Humans | Comment 27 January 2021
    By James Wong

    Oliver Dixon/Shutterstock

    IT ISN’T an exaggeration to say that in the world of horticulture “native” is frequently used as a byword for “better”. Native plants are often considered easier to grow and better for wildlife, while also being less invasive and more resistant to pests.
    This belief is so institutionalised that many local planning rules in the UK specify that a certain percentage of landscaping schemes must include native species. Indeed, this conviction runs so deep that some see sharing evidence to the contrary as being hugely controversial, even deeply irresponsible. But accuracy is what matters, so let’s explore … More

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    Why using rare metals to clean up the planet is no cheap fix

    Demand for rare metals can only increase in the move to a zero-carbon economy. The Rare Metals War by Guillaume Pitron lays out the terrifying cost

    Humans 27 January 2021
    By Simon Ings
    A man working at a rare earth metals mine in Nancheng county, China
    REUTERS/Stringer

    The Rare Metals War
    Guillaume Pitron (translator Biana Jacobsohn)
    Scribe

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    WE REAP seven times as much energy from the wind and 44 times as much energy from the sun as we did a decade ago. Is this good news? Guillaume Pitron, a French journalist and documentary maker, isn’t sure.
    He is neither a climate sceptic nor a fan of inaction. But as the world moves to adopt a target of net-zero carbon emissions by 2050, Pitron worries about the costs. The figures in his book The Rare Metals War are stark. Changing the energy model means doubling the production of rare metals about every 15 years, mostly to satisfy demand for non-ferrous magnets and lithium-ion batteries. “At this rate,” writes Pitron, “over the next 30 years we… will need to mine more mineral ores than humans have extracted over the last 70,000 years.”
    Before the Renaissance, humans had found uses for seven metals. During the industrial revolution, this increased to a mere dozen. Today, we have found uses for all 90-odd of them, and some are very rare. Neodymium and gallium, for instance, are found in iron ore, but there is 1200 times less neodymium and up to 2650 times less gallium than there is iron.
    Zipping from an abandoned mine in the Mojave desert to the toxic lakes and cancer-afflicted areas of Baotou in China, Pitron weighs the awful price of refining the materials, ably blending investigative journalism with insights from science, politics and business.
    There are two sides to Pitron’s story, woven seamlessly together. First, there is the economic story of how China worked to dominate the energy and digital transition. It now controls 95 per cent of the rare earth metals market, making between 80 and 90 per cent of the batteries for electric vehicles, says Pitron, and more than half the magnets in wind turbines and electric motors.

    Then there is the ecological story of the lengths China took to succeed. Today, 10 per cent of its arable land is contaminated by heavy metals, 80 per cent of its groundwater isn’t fit for consumption and air pollution contributes to around 1.6 million deaths a year there, according to Pitron (a recent paper in The Lancet says 1.24 million deaths in China a year are attributable to air pollution – but let’s not quibble).
    China freely entered into this Faustian bargain. Yet it wouldn’t have been possible had the Western world not outsourced its own industrial activities, creating a planet divided, as Pitron memorably describes it, “between the dirty and those who pretend to be clean”.
    The West’s comeuppance is at hand, as its manufacturers, starved of rare metals, must take their technologies to China. It should have seen how its reliance on Chinese raw materials would quickly morph into a dependence on China for the technologies of the energy and digital transition.
    By 2040, in our pursuit of ever-greater connectivity and a cleaner atmosphere, we will need to mine three times more rare earth metals, five times more tellurium, 12 times more cobalt and 16 times more lithium than we do now. China’s ecological ruination and global technological dominance advance in lockstep, unstoppably, unless the West and others start to mine for rare metals in Brazil, the US, Russia, Turkey, South Africa, Thailand and Pitron’s native France.
    Better that the West attains some shred of supply security by mining some of its own land, says Pitron. At least there consumers can fight (and pay) for cleaner processes. Nothing will change if we don’t experience “the full cost of attaining our standard of happiness”, he says.

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    Last and First Men review: An epic 2-billion-year history of humanity

    Last and First Men tracks the beginning and end of humanity. It is a film that ranks with Solaris and 2001: A Space Odyssey and it may even break your heart, says Simon Ings

    Humans 27 January 2021
    By Simon Ings
    Last and First Men uses eerie architectural shots to explore humanity’s end
    Sturla Brandth Grovlen

    Last and First Men
    Jóhann Jóhannsson
    Streaming on BFI Player

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    “IT’S a big ask for people to sit for 70 minutes and look at concrete,” mused Icelandic composer Jóhann Jóhannsson about his only feature-length film. He was still working on Last and First Men when he died, aged 48, in 2018.
    Admired for his keening orchestral pieces, Jóhannsson was well known for his film work: Prisoners and Sicario were made strange by his sometimes terrifying, thumping soundtracks.
    Last and First Men is, by contrast, contemplative and surreal. It uses a series of zooms and tracking shots set against eerie architectural forms, shot in monochrome 16-millimetre film by Norwegian cinematographer Sturla Brandth Grøvlen.
    The film draws its inspiration and script (a haunting, sometimes chilly, off-screen monologue performed by Tilda Swinton) from Olaf Stapledon’s 1930 novel of the same name. His day job at the time of writing – lecturing on politics and ethics at the University of Liverpool, UK – seems of little moment now, but his sci-fi novels have barely been out of print and still set a dauntingly high bar.
    Last and First Men is a 2-billion-year history, detailing the dreams, aspirations, achievements and failings of 17 different kinds of future humans (Homo sapiens is first). In the light of an ageing sun, they evolve, blossom, speciate, die; the film is set in the moment of extinction.

    Stapledon’s book isn’t a drama. There are no actors or action. It isn’t really a novel, more a haunting academic paper from the beyond. The idea to use the book came late in Jóhannsson’s project, which began life as a film essay on Spomeniks, the huge, brutalist war memorials erected in the Socialist Federal Republic of Yugoslavia between the 1960s and the 1980s by dictator Jozip Broz Tito.
    “Who knew that staring at concrete and listening to the end of humanity could wet the watcher’s eye?”
    In 2017, the film, with a live performance of an early score, was screened at the Manchester International Festival. Jóhannsson told the audience how Tito thought he was building a utopian experimental state that would unite Slavic nations. Because there were so many different religions, the architects looked to Mayan and Sumerian art, rather than religious icons. “That’s why they [spomeniks] look so alien and otherworldly,” he explained.
    Swinton’s regretful monologue proves an ideal foil for the film’s explorations, lifting what would be a stunning but slight piece into dizzying, speculative territory: the last living human, contemplating the leavings of 2 billion years.
    Last and First Men was left unfinished. The film was cut and Swinton had recorded the monologue by the time the film was presented at the Manchester International Festival. As far as Jóhannsson was concerned, there was still a lot to be done to finish the score. On his death, Yair Elazar Glotman was brought on board to arrange his notes and come up with a final performance for the soundtrack. No one hearing how the film was put together would imagine it could amount to more than a tribute, but sometimes the gods are kind. It is hugely successful, wholly deserving of a place beside Andrei Tarkovsky’s Solaris and Stanley Kubrick’s 2001: A Space Odyssey.
    Who knew that staring at concrete and listening to the end of humanity could wet the watcher’s eye and break their heart? It is tragic that Jóhannsson didn’t live to see that, in his own words, “we’ve taken all these elements and made something beautiful and poignant. Something like a requiem.”

    Simon also recommends…
    Film
    La Jetée (1962)
    Directed by Chris Marker
    This short black-and-white film, assembled mostly from stills, is a masterful tale of love, apocalypse and time travel. The story inspired Terry Gilliam’s 1995 thriller 12 Monkeys.
    Book
    Summa Technologiae
    Stanislaw Lem
    The Polish parodist and sci-fi writer’s only full-length philosophical work projects humanity into the future and explains why we are doomed to mess it up.

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    An unscientific debate over breast milk is spilling into food banks

    An overzealous push for breastfeeding is affecting availability of baby formula in food banks, worsening problems for the poorest people, writes Clare Wilson

    Health | Comment 27 January 2021
    By Clare Wilson

    Michelle D’urbano

    WITH many people enduring extreme hardship because of the covid-19 pandemic, food banks in the UK are providing a more important function than ever. These vital institutions, funded mainly through public donations, act as a safety net so those in financial crisis at least don’t go hungry.
    But there is one section of society who cannot always benefit from their support, and they are among the most vulnerable group of all: infants. In the UK, most babies are entirely or mainly dependent on formula milk.
    Baby milk takes up a hefty chunk of a low-income family’s food budget. It can cost up to £30 a week and most food banks don’t stock formula milk because it is seen as clashing with breastfeeding promotion.

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    Some local authorities and health boards explicitly tell food banks not to supply it, often citing recent UN guidelines on the issue, according to a recent report from Feed, a Scottish-based charity that aims to provide impartial advice on infant feeding.
    The resistance to providing formula milk stems from a long-running dispute over infant feeding. In the past, some manufacturers wrongly claimed that their formula milk was the healthiest choice. Today, we know that breast milk contains a range of beneficial substances like antibodies that fight off microbes and there is some evidence that breastfed babies have fewer infections in their first year of life.
    But many of the broader claims about the benefits that breastfeeding can lead to in later life, like protecting against obesity and asthma, and raising IQ, may not be true. Studies suggest that these apparent correlations arise because, in high-income countries like the UK, breastfeeding is more common among better-off families.
    Child health organisations tend to say that if families have a baby that they can’t feed, they need specialist help, which is best given by referring them to health or social services. This can take time, however, and people are resorting to watering down formula or giving unsuitable milk alternatives, which risks babies’ health, Feed’s investigation has found.

    It isn’t as if families can simply switch from formula milk to breastfeeding if financial circumstances change. When someone stops breastfeeding, or doesn’t start, milk production ceases. So saying that someone ought to breastfeed when they are unable to is about as helpful as saying someone ought not to be poor.
    Health benefits aside, not everyone can breastfeed. For example, a woman may not make enough milk or be on medication that would be harmful for their baby if they did breastfeed.
    Breastfeeding can also be painful and take up a lot of time and effort. It is often said that breastfeeding is free, but that is only the case if you view women’s time and labour as financially worthless.
    In other words, breast isn’t always best, and only the people involved can decide if the health benefits outweigh any toll to well-being to make that decision.
    In the past decade or so, breastfeeding promotion has been overzealous, making some who use formula milk feel so guilty it threatens their mental health. It has triggered a backlash from groups, such as Fed is Best, that say the health system shouldn’t try to control people’s bodies in this way.
    People who have so little money that they need handouts of food may be in no position to argue with health workers over their personal autonomy – but it is a disgrace that the often unscientific debate over breast milk versus baby formula is harming the most vulnerable. It has to stop.
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    Was it just luck that our species survived and the Denisovans didn't?

    Sputnik/Science Photo Library
    THE human story only becomes more intricate and fascinating. For hundreds of thousands of years, a mysterious group known as the Denisovans lived in the east of Asia – even as our species was emerging in Africa and beginning to spread around the world. Their homeland spanned thousands of kilometres and they existed as a group longer than we have as a species. Yet they were utterly unknown until 2010, when they were identified from DNA preserved in a bone fragment.
    A decade later, the Denisovans remain enigmatic. We know they were a sister group to the Neanderthals, … More

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    Using hand gestures when we talk influences what others hear

    By Ibrahim Sawal
    Hand gestures affect the way people hear you
    Getty Images/Westend61

    Making simple up and down hand movements while speaking may influence the way people hear what you are saying.
    We often use meaningless movements, such as flicking or waving our hands, known as beat gestures when speaking face to face. These typically align with prominent words in speech.
    “Politicians use these gestures all the time to get their message across,” says Hans Rutger Bosker at the Max Planck Institute for Psycholinguistics in Nijmegen, the Netherlands.

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    Bosker and his colleagues tested how important these movements are in influencing sound recognition. They presented Dutch participants with videos of Bosker saying Dutch words that have two meanings depending on which syllables are stressed – an example in English would be the difference between object and object. Bosker paired each word with a beat gesture either on the first syllable or the second syllable.
    The team found that participants were on average 20 per cent more likely to hear stress on a syllable if there was a beat gesture on it. Mismatched beat gestures also biased what they heard, with 40 per cent of participants hearing the wrong sound.

    “The timing of even the simplest hand movement is vital to face-to-face communication,” says Bosker. “We’ve shown how multimodal speech perception really is,” he says.
    This could be a learned association, but there could be an evolutionary reason behind it says Wim Pouw at Radboud University in Nijmegen, who wasn’t involved in the research. “Manual gestures, like those with a beat quality, interact with the vocal system by using muscles that can increase lung pressure. This affects vocal qualities associated with stressed speech,” says Pouw. He suggests that observing these gestures helps us to perceive these changes in vocal qualities.
    Although only tested in Dutch, Bosker says similar effects may be seen in other similar languages such as English, and may even be present in all languages. “This effect could be generalised to much more than just Dutch, but this is highly speculative,” he says.

    Bosker says that his research is even more important during the current coronavirus pandemic. “With people wearing face masks, we can’t lip read. Our data explains how much communication can be improved if we gesture along,” he says.
    Journal reference: Proceedings of the Royal Society B, DOI: 10.1098/rspb.2020.2419
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    The other humans: The emerging story of the mysterious Denisovans

    The existence of the Denisovans was discovered just a decade ago through DNA alone. Now we’re starting to uncover fossils and artefacts revealing what these early humans were like

    Humans 27 January 2021
    By Michael Marshall

    Brian Stauffer

    TODAY, there is only one species of human alive on the planet. But it wasn’t always so. For millions of years, and until surprisingly recently, there were many types of human-like groups, or “hominins”. They coexisted, perhaps they fought, and they interbred. It would be fascinating to know how these others lived, but understanding who they were and what they were like is extremely challenging. We cannot put ourselves into their minds, and we have only fragmentary clues from fossils and artefacts they left behind to reconstruct their lives.
    That challenge is especially daunting for one of these extinct groups, the Denisovans. Discovered just a decade ago, the Denisovans have left us scant physical evidence. Instead, our knowledge of them comes almost entirely from their preserved DNA. It tells us that they are a sister group to the Neanderthals, that they lived in Asia for hundreds of thousands of years and that they interbred with our species. But we don’t know what they looked like, how they walked or if they could speak.
    Now, that is changing. In the past few years, archaeologists have alighted on a few fossils that seem to be Denisovan. They have also unearthed treasure troves of artefacts, including tools, jewellery and even art, that they think were created by these mysterious people. These interpretations are potentially explosive, so it is hardly surprising that some dispute them. Nevertheless, we are starting to piece together a picture of the Denisovans, one of our closest cousins, and a group that still lives on in the DNA of many people today.
    The discovery of the Denisovans … More

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    Crushed space rocks hint at exoplanets’ early atmospheric makeup

    Burning bits of ground-up meteorites may tell scientists what exoplanets’ early atmospheres are made of.
    A set of experiments baking the pulverized space rocks suggests that rocky planets had early atmospheres full of water, astrophysicist Maggie Thompson of the University of California, Santa Cruz reported January 15 at the virtual meeting of the American Astronomical Society. The air could also have had carbon monoxide and carbon dioxide, with smaller amounts of hydrogen gas and hydrogen sulfide.
    Astronomers have discovered thousands of planets orbiting other stars. Like the terrestrial planets in the solar system, many could have rocky surfaces beneath thin atmospheres. Existing and future space telescopes can peek at starlight filtering through those exoplanets’ atmospheres to figure out what chemicals they contain, and if any are hospitable to life (SN: 4/19/16).
    Thompson and her colleagues are taking a different approach, working from the ground up. Instead of looking at the atmospheres themselves, she’s examining the rocky building blocks of planets to see what kind of atmospheres they can create (SN: 5/11/18).

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    The researchers collected small samples, about three milligrams per experiment, of three different carbonaceous chondrite meteorites (SN: 8/27/20). These rocks are the first solids that condensed out of the disk of dust and gas that surrounded the young sun and ultimately formed the planets, scientists say. The meteorites form “a record of the original components that formed planetesimals and planets in our solar system,” Thompson said in a talk at the AAS meeting. Exoplanets probably formed from similar stuff.
    The researchers ground the meteorites to powder, then heated the powder in a special furnace hooked up to a mass spectrometer that can detect trace amounts of different gases. As the powder warmed, the researchers could measure how much of each gas escaped.
    That setup is analogous to how rocky planets formed their initial atmospheres after they solidified billions of years ago. Planets heated their original rocks with the decay of radioactive elements, collisions with asteroids or other planets, and with the leftover heat of their own formation. The warmed rocks let off gas. “Measuring the outgassing composition from meteorites can provide a range of atmospheric compositions for rocky exoplanets,” Thompson said.
    All three meteorites mostly let off water vapor, which accounted for 62 percent of the gas emitted on average. The next most common gases were carbon monoxide and carbon dioxide, followed by hydrogen, hydrogen sulfide and some more complex gases that this early version of the experiment didn’t identify. Thompson says she hopes to identify those gases in future experimental runs.
    The results indicate astronomers should expect water-rich steam atmospheres around young rocky exoplanets, at least as a first approximation. “In reality, the situation will be far more complicated,” Thompson said. Planets can be made of other kinds of rocks that would contribute other gases to their atmospheres, and geologic activity changes a planet’s atmosphere over time. After all, Earth’s breathable atmosphere is very different from Mars’ thin, carbon dioxide-rich air or Venus’s thick, hot, sulfurous soup (SN: 9/14/20).
    Still, “this experimental framework takes an important step forward to connect rocky planet interiors and their early atmospheres,” she said.
    This sort of basic research is useful because it “has put a quantitative compositional framework on what those planets might have looked like as they evolved,” says planetary scientist Kat Gardner-Vandy of Oklahoma State University in Stillwater, who was not involved in this new work. She studies meteorites too and is often asked whether experiments that crush the ancient, rare rocks are worth it.
    “People inevitably will ask me, ‘Why would you take a piece of a meteorite and then ruin it?’” she says. “New knowledge from the study of meteorites is just as priceless as the meteorite itself.” More