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Credit: Katie Orlinsky for National Geographic
The month’s best science images
This aerial view shows the Batagaika crater, a massive land slump in Siberia that formed in the 1960s when deforestation caused the permafrost to melt. The tadpole-shaped crater is about one kilometre long and nearly 90 metres deep, and grows year by year as the warming climate thaws the frozen ground. The layers of sediment on its exposed walls offer a glimpse into 200,000 years of Earth’s geological history, and ice-age fossils have been found buried in the sediment. This photo was taken by photographer Katie Orlinsky as part of a series on permafrost that was awarded third prize in the environment category of the 2020 World Press Photo Awards.See more of the month’s sharpest science shots, selected by Nature’s photo team.
Exotic matter meets exotic dark matter
A device will use the ‘fifth state of matter’ to search for axions, a relatively neglected candidate for dark matter. The ‘comagnetometer’ consists of two extremely sensitive magnetic-field detectors made from rubidium-87 atoms. The atoms are cooled to near absolute zero to create a Bose–Einstein condensate, so each essentially acts as a single atom. Because they have different spin states that respond differently to magnetic fields, any variation measured by the two detectors could signal the presence of axions.
Reference: Physical Review Letters paper
COVID-19 coronavirus outbreak
Children and the spread of COVID-19
Children represent a small fraction of confirmed COVID-19 cases, but researchers are divided on how susceptible they are to infection and how much they contribute to the disease’s spread. Some scientists point to a growing body of evidence suggesting that children are at lower risk of infection and are not responsible for the majority of transmission — and thus we can reopen schools. Others argue that the incidence of infection in children is lower than in adults partly because they haven’t been exposed to the virus as much — especially with many schools closed. Children are also not getting tested as often because they have mild or no symptoms. If this is the case, we’ll see infections spike in places where kids return to class.
Settling the debate will require large, high-quality population studies — some of which are already under way — that include antibody tests for previous infection. Scientists are also seeking answers to why children seem to suffer less from the infection, and how it might help the rest of us.
One strain is enough to worry about
Despite some news reports, it’s too soon to say whether there is more than one strain of the SARS-CoV-2 coronavirus — let alone one that’s more dangerous or more contagious. The virus does mutate, and tracking how it changes helps to trace its spread — which is beautifully visualized on Nextstrain. But scientists generally consider these variations to be the same strain because there is no strong evidence of significant differences, such as in how easily they spread.
Features & opinion
The hidden links between mental disorders
Seeking the roots of mental illness, researchers have found that many of the same genes underlie seemingly distinct disorders. Now, psychiatrists are turning away from the old system of categorizing mental disorders into neat boxes. Instead, they’re building a framework grounded in biology that will hopefully improve diagnosis, treatment and understanding of the underlying causes.
Source: Ref. 8
Podcast: Galileo and the science deniers
“Eppur si muove” — “And yet it moves”. That phrase, supposedly muttered by Galileo Galilei after his conviction for heresy, has become a symbol of intellectual defiance against science denialism. Astronomer Mario Livio talks to Nature Podcast about his new biography of the Pisan scientist, and the role he played in establishing the scientific method. “He really started the modern way of doing physics — and science in general,” Livio says.
Nature Podcast | 22 min listen
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Five best science books this week
Andrew Robinson’s pick of the top five science books to read this week includes smart-technology spies, a final warning on the environment and the staggering costs of cancer.
Where I work
Israel Hershkovitz is director of the Dan David Center for Human Evolution and Biohistory Research at Tel Aviv University.Credit: Corinna Kern for Nature
Anthropologist Israel Hershkovitz uses a pneumatic drill on a half-tonne breccia to gently expose the bones of a human who lived between 100,000 and 120,000 years ago. He and a colleague dug the sedimentary block from a cave in central Israel, and realized that it could hide evidence of the earliest known deliberate burial. “I call myself a biohistorian,” Hershkovitz says. “I’m trying to understand human history, not from human artefacts, temples or big walls surrounding old cities, but from bones.” (Nature | 3 min read)
