Philippa Kaur

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    in Humans

    How four big industries are driving the exploitation of our oceans

    From deep-sea mines to aquaculture, bioprospecting and energy generation, humanity’s accelerating expansion into the high seas has potentially huge consequences for its health

    Humans

    20 April 2022

    By Graham Lawton
    Wind power could require 45,000 km2 of European waters by 2050Miguel Navarro/Getty Images
    BLUE BUSINESS: Power and comms
    The world’s first offshore wind farm opened off the coast of Lolland, Denmark, in 1991. Since then, the global installed capacity has grown to nearly 35 gigawatts – enough to power the entire UK – almost all of it in European (25 GW) and Chinese (9 GW) waters. Other sources of ocean renewable energy are also being eyed up, including waves, tides, currents, salinity gradients, thermal gradients and marine biomass. The EU has a target of installing 1 GW of these alternative sources by 2030, says Benjamin Lehner at the Dutch Marine Energy Centre in The Hague.
    All these figures are a drop in the ocean compared with the world’s 1840 GW of gas-fired power capacity. Yet with wind power generation getting cheaper all the time – costs declined 70 per cent between 2012 and 2021 – rapid growth looks like a foregone conclusion. The trade association Wind Europe estimates that, by 2050, Europe will have 450 GW of offshore wind.
    That brings its own challenges. It will require about 45,000 square kilometres of ocean, most of it between 11 and 22 kilometres from shore, the goldilocks zone for offshore wind. Europe has 550,000 square kilometres of this real estate in total, but more than 60 per cent is earmarked for marine protected areas, says António Sarmento at consultancy firm WavEC Offshore Renewables in Lisbon, Portugal. Building, operating and maintaining offshore wind farms can damage the seabed, while the power cables that carry electricity to shore … More

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    in Space & Astronomy

    ‘Goldilocks’ stars may pose challenges for any nearby habitable planets

    If you’re an aspiring life-form, you might want to steer clear of planets around orange dwarf stars.

    Some astronomers have called these orange suns “Goldilocks stars” (SN: 11/18/09). They are dimmer and age more slowly than yellow sunlike stars, thus offering an orbiting planet a more stable climate. But they are brighter and age faster than red dwarfs, which often spew large flares. However, new observations show that orange dwarfs emit lots of ultraviolet light long after birth, potentially endangering planetary atmospheres, researchers report in a paper submitted March 29 at arXiv.org.

    Using data from the Hubble Space Telescope, astronomer Tyler Richey-Yowell and her colleagues examined 39 orange dwarfs. Most are moving together through the Milky Way in two separate groups, either 40 million or 650 million years old.

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    To Richey-Yowell’s surprise, she and her team found that the ultraviolet flux didn’t drop off from the younger orange stars to the older ones — unlike the case for yellow and red stars. “I was like, `What the heck is going on?’” says Richey-Yowell, of Arizona State University in Tempe.

    In a stroke of luck, another team of researchers supplied part of the answer. As yellow sunlike stars age, they spin more slowly, causing them to be less active and emit less UV radiation. But for orange dwarfs, this steady spin-down stalls when the stars are roughly a billion years old, astronomer Jason Lee Curtis at Columbia University and colleagues reported in 2019.

    “[Orange] stars are just much more active for a longer time than we thought they were,” Richey-Yowell says. That means these possibly not-so-Goldilocks stars probably maintain high levels of UV light for more than a billion years.

    And that puts any potential life-forms inhabiting orbiting planets on notice. Far-ultraviolet light — whose photons, or particles of light, have much more energy than the UV photons that give you vitamin D — tears molecules in a planet’s atmosphere apart. That leaves behind individual atoms and electrically charged atoms and groups of atoms known as ions. Then the star’s wind — its outflow of particles — can carry the ions away, stripping the planet of its air.

    But not all hope is lost for aspiring life-forms that have an orange dwarf sun. Prolonged exposure to far-ultraviolet light can stress planets but doesn’t necessarily doom them to be barren, says Ed Guinan, an astronomer at Villanova University in Pennsylvania who was not involved in the new work. “As long as the planet has a strong magnetic field, you’re more or less OK,” he says.

    Though far-ultraviolet light splits water and other molecules in a planet’s atmosphere, the star’s wind can’t remove the resulting ions if a magnetic field as strong as Earth’s protects them. “That’s why the Earth survived” as a life-bearing world, Guinan says. In contrast, Venus might never have had a magnetic field, and Mars lost its magnetic field early on and most of its air soon after.

    “If the planet doesn’t have a magnetic field or has a weak one,” Guinan says, “the game is over.”

    What’s needed, Richey-Yowell says, is a study of older orange dwarfs to see exactly when their UV output declines. That will be a challenge, though. The easiest way to find stars of known age is to study a cluster of stars, but most star clusters get ripped apart well before their billionth birthday (SN: 7/24/20). As a result, star clusters somewhat older than this age are rare, which means the nearest examples are distant and harder to observe. More

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    in Space & Astronomy

    Crumbling planets might trigger repeating fast radio bursts

    Fragmenting planets sweeping extremely close to their stars might be the cause of mysterious cosmic blasts of radio waves.

    Milliseconds-long fast radio bursts, or FRBs, erupt from distant cosmic locales. Some of these bursts blast only once and others repeat. A new computer calculation suggests the repetitive kind could be due to a planet interacting with its magnetic host star, researchers report in the March 20 Astrophysical Journal.

    FRBs are relative newcomers to astronomical research. Ever since the first was discovered in 2007, researchers have added hundreds to the tally. Scientists have theorized dozens of ways the two different types of FRBs can occur, and nearly all theories include compact, magnetic stellar remnants known as neutron stars. Some ideas include powerful radio flares from magnetars, the most magnetic neutron stars imaginable (SN: 6/4/20). Others suggest a fast-spinning neutron star, or even asteroids interacting with magnetars (SN: 2/23/22).

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    “How fast radio bursts are produced is still up for debate,” says astronomer Yong-Feng Huang of Nanjing University in China.

    Huang and his colleagues considered a new way to make the repeating flares: interactions between a neutron star and an orbiting planet (SN: 3/5/94). Such planets can get exceedingly close to these stars, so the team calculated what might happen to a planet in a highly elliptical orbit around a neutron star. When the planet swings very close to its star, the star’s gravity pulls more on the planet than when the planet is at its farthest orbital point, elongating and distorting it. This “tidal pull,” Huang says, will rip some small clumps off the planet. Each clump in the team’s calculation is just a few kilometers wide and maybe one-millionth the mass of the planet, he adds.

    Then the fireworks start. Neutron stars spew a wind of radiation and particles, much like our own sun but more extreme. When one of these clumps passes through that stellar wind, the interaction “can produce really strong radio emissions,” Huang says. If that happens when the clump appears to pass in front of the star from Earth’s perspective, we might see it as a fast radio burst. Each burst in a repeating FRB signal could be caused by one of these clumps interacting with the neutron star’s wind during each close planet pass, he says. After that interaction, what remains of the clump drifts in orbit around the star, but away from Earth’s perspective, so we never see it again.

    Comparing the calculated bursts to two known repeaters — the first ever discovered, which repeats roughly every 160 days, and a more recent discovery that repeats every 16 days, the team found the fragmenting planet scenario could explain how often the bursts happened and how bright they were (SN: 3/2/16).

    The star’s strong gravitational “tidal” pull on the planet during each close pass might change the planet’s orbit over time, says astrophysicist Wenbin Lu of Princeton University, who was not involved in this study but who investigates possible FRB scenarios. “Every orbit, there is some energy loss from the system,” he says. “Due to tidal interactions between the planet and the star, the orbit very quickly shrinks.” So it’s possible that the orbit could shrink so fast that FRB signals wouldn’t last long enough for a chance detection, he says.

    But the orbit change could also give astronomers a way to check this scenario as an FRB source. Observing repeating FRBs over several years to track any changes in the time between bursts could narrow down whether this hypothesis could explain the observations, Lu says. “That may be a good clue.” More

  • 138 Shares139 Views

    in Humans

    People tend to believe populations are more diverse than they are

    In 12 psychological experiments with a total of 942 participants, 82 per cent overestimated the presence of individuals from minority ethnic groups

    Humans

    14 April 2022

    By Jason Arunn Murugesu
    A stock image of a group of people of a range of ethnicitiesShutterstock/Rawpixel.com
    People may subconsciously overestimate the presence of individuals from minority ethnic groups, even if they belong to those groups, which could create illusions of diversity within populations.
    “Individuals from the minority group are by definition less frequent,” says Rasha Kardosh at the Hebrew University of Jerusalem in Israel. “Therefore, we are more likely to notice them and so are more likely to remember their presence, and so we end up overestimating their presence.”
    Previous studies suggest people in … More

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    in Humans

    Earliest evidence for Maya calendar may have been found in Guatemala

    The earliest evidence of calendar use by the Maya may have been found in the remains of an ancient temple in Guatemala

    Humans

    13 April 2022

    By Carissa Wong
    An ancient fragment of a Maya calendarHeather Hurst/Skidmore College/Saratoga Springs
    Two pieces of an ancient wall may preserve the earliest evidence of the Maya calendar. The fragments are decorated with a dot and line above a deer head – representing one of the dates from the 260-day calendar – and they are from a temple built between 2300 and 2200 years ago in what is now Guatemala in central America.
    Several ancient communities living across the Americas – including the Aztecs, Maya, Mixtecs and Zapotecs – tracked the time using cycles of 13 days denoted by numbers, alongside cycles of 20 days named after gods. In this calendar, a specific day is assigned both a number and a name, producing 260 unique days before the cycle repeats. It is thought that people used the calendar to decide when to hold ceremonies, to mark important dates or to attempt to predict future events.
    Until now, most previous early evidence for calendar use by these ancient people had been found on stone monuments dating to around 100 BC. David Stuart at the University of Texas at Austin and his colleagues have now found evidence that the Maya people may have used this calendar over a century earlier.Advertisement
    The team previously discovered the San Bartolo archaeological site, which includes a pyramid called Las Pinturas – meaning “the paintings” – back in 2001. Excavations then revealed that the Maya completed several phases of construction, with earlier structures eventually knocked down to form the foundations of the pyramid.
    When the researchers were sorting through pieces of plaster collected from the pyramid’s foundations, they realised that two pieces fit perfectly together to form a date symbol.
    “That was a stunner – we believe that this is the earliest example of the use of the Maya calendar, showing the day seven Deer,” says Stuart.

    The fragments came from the remains of a long platform that was probably built to track astronomical events as well as the time. “This platform may have acted as an observatory for looking at the rising sun or other astronomical bodies in the sky, or for just keeping track of time. Like a kind of architectural clock,” says Stuart.
    By radiocarbon dating charcoal found alongside the fragments, the team dated the symbols to between 300 and 200 BC. Stuart believes the symbols may have been used to denote the date of a new year, but they may also have been used to reference a person or deity.
    However, some archaeologists question whether this is really the earliest evidence of the 260-day calendar. Mary Pohl at Florida State University believes that a previously discovered roller stamp from Tabasco in Mexico shows this date notation was used in 500 BC. But Stuart thinks the symbols on the stamp from 500 BC aren’t necessarily a form of date notation comparable to the Maya system.
    “Early evidence of the… calendar has been debated, but in this study they present clear evidence of the 260-day calendar use. This is very important work,” says Takeshi Inomata at the University of Arizona.
    Journal reference: Science Advances, DOI: 10.1126/sciadv.abl9290
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    in Humans

    Women in a 19th-century Dutch farming village didn't breastfeed

    An analysis of bones from about 500 individuals who died between 1830 and 1867 in Middenbeemster suggests women in the dairy farming community did not breastfeed

    Health

    13 April 2022

    By Jason Arunn Murugesu
    Engraving from From The Five Senses by Fredrick Bloemaert, after Abraham Bloemaert, 1632-1670F. Bloemaert/A. Bloemaert/N. Visscherimage/Rijks Museum/Public Domain
    Women from a 19th-century farming community in the Netherlands probably didn’t breastfeed their babies because they were too busy working. It is the first time that widespread artificial feeding has been discovered in a farming community from this period.
    Andrea Waters-Rist at Western University in Canada and her colleagues analysed the bones of about 500 individuals who died between 1830 and 1867 in Middenbeemster, a rural village in the north of the Netherlands.
    The remains were dug up because a church was expanding into the cemetery, and Waters-Rist and her team were offered the chance to analyse them. They also had death certificates for about half the people. “It’s really rare to have such a large sample size and to have all this amazing archival information,” she says.Advertisement
    The researchers wanted to find out more about the diets of the women and children in this village, which mainly consisted of dairy farmers at this time. “One of the main reasons behind this type of research is to rectify the historical record about the lives of women and children,” says Waters-Rist. “Traditional archaeology has focused on what adult males were doing and women were just seen as passive actors.”
    The team was able to determine whether the children were breastfed by analysing the chemical isotopes in their bones. Children who are breastfed have different carbon and nitrogen isotope ratios to their mothers.

    Out of 20 children who had died before the age of 1, 15 showed no evidence of breastfeeding. “Even the five who did show some sign – it did not seem like they were breastfed for long,” says Waters-Rist.
    And out of 35 children aged between 1 and 6, 29 showed no signs of breastfeeding in their bones. The team believes this was probably due to the fact that women predominantly worked the farms in this community, milking and raising the cows.
    “We think it’s a sign of how hard the women were working and that they were just really busy,” she says. “Also, there was always fresh cow’s milk.”
    Waters-Rist says this has never been seen among farmers from this period before. “We’ve only seen this behaviour in really large cities where women were working in factories and couldn’t take their babies with them,” she says.
    “The findings of this study are intriguing for an agricultural community where mothers and infants would not have spent long periods apart,” says Ellen Kendall at Durham University in the UK. But she says the results may be skewed by only looking at children who died before the age of six – it could be that children who weren’t breastfed were more likely to die early.
    Journal reference: PLOS One, DOI: https://dx.doi.org/10.1371/journal.pone.0265821

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    in Humans

    Apollo 10½: A smart animation about growing up during the space age

    Richard Linklater’s latest film follows a young boy’s fantasies about travelling to space, using beautiful rotoscoped animation to tell his story, says Simon Ings

    Humans

    13 April 2022

    By Simon Ings

    Film
    Apollo 10½: A space age childhood
    Richard Linklater
    Netflix
    WHAT we really seek in space is “not knowledge, but wonder, beauty, romance, novelty – and above all, adventure”, sci-fi writer Arthur C. Clarke told the American Aeronautical Society in 1967, as the gloss was beginning to flake off the Apollo project.
    By the time Apollo 11 launched on 16 July 1969, NASA’s bid to land astronauts on the moon (the most expensive civilian undertaking in history) couldn’t help but be overshadowed by the even more costly Vietnam war.
    Only a little of this trickles into the consciousness of 10-year-old Stan … More

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    in Humans

    How interior design choices can boost your mental and physical health

    Neuroscientists have figured out what interior design choices, from flooring to lighting, can help create homes that improve our mental health, decrease stress and fatigue, and even spark creativity

    Humans

    13 April 2022

    By David Robson
    Leonie Bos
    YOU might recognise the sensation from visits to a friend’s house – the feeling that a space is good for you. Perhaps it is a sense of profound relaxation, as if you left your worries at the door. Or you may have found the perfect office space that leaves you buzzing with creative ideas. Yet try to explain why you felt that way, or recreate those effects at home, and you fall short.
    According to the ancient Chinese practice of feng shui, there are rules of harmonious living that affect the flow of energy through your body, and many modern design gurus take a similar line, dishing out guidance in lifestyle magazines and Instagram accounts. They advise on the shape of rooms, materials in furnishings, colours on walls and organisation of books – it may make your home look good, but does it make you feel good?
    While there is nothing wrong with going with your gut when it comes to decor, there could be a better way to make design choices. A growing number of neuroscientists are collaborating with architects and interior designers. With carefully controlled experiments using objective physiological and psychological measures, they are starting to systematically test the influence of design elements on brain and body.
    The work couldn’t be timelier. The rise of remote working has meant more time at home for many. Whether you want to boost your mood, lower your blood pressure, decrease your bad habits or ease the burden of dementia, this research can provide evidence-based strategies to optimise your living space for your physical and mental health.
    The roots of this work lie in … More