New Scientist 10-Jul-21

New Scientist covers the latest developments in science and technology that will impact your world. New Scientist employs and commissions the best writers in their fields from all over the world. Our editorial team provide cutting-edge news, award-winning features and reports, written in concise and clear language that puts discoveries and advances in the context of everyday life today and in the future.

国家:
United Kingdom
语言:
English
出版商:
New Scientist Ltd
出版周期:
Weekly
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51 期号

本期

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elsewhere on new scientist

Virtual events The first stars We are missing the first billion years from the timeline of the universe – the period when the very first stars burst into life and darkness gave way to light. Hundreds of times the size of the sun and a million times brighter, these stars died in powerful explosions that seeded the universe with the heavier elements that we are made of. In this talk, Emma Chapman at Imperial College London explains how astronomers are coming together to look further back in time. Join us at 6pm BST on Thursday 22 July. Tickets are available now. newscientist.com/event Podcasts Weekly The team asks whether an ancient skull discovered in China belongs to a new species of humans, explores how covid-19 affects the brain and discusses several other stories. newscientist.com/podcasts Video Surfing sharks Researchers have found that…

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high-stakes gamble

SOME call it a calculated risk, others a reckless gamble. Earlier this week, UK prime minister Boris Johnson announced that almost all remaining covid-19 restrictions in England are set to be lifted on 19 July, now called, by some, “freedom day”. This may be good politics, but is it good public health policy? Scientific opinion is divided. The UK’s vaccination programmes are hitting one of their goals: to decouple infection from severe disease and reduce the need for masks and distancing. Even in the face of the highly transmissible delta variant, cases are rising but hospitalisations aren’t going up too much. That is good, given that the new UK health secretary, Sajid Javid, says cases could hit 100,000 a day as a result of easing restrictions (see page 9). There is also…

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in the line of fire

ON 29 June, the village of Lytton in British Columbia recorded a temperature of 49.6°C, smashing Canadian records. The following day, fire swept through it, razing much of it to the ground. Last week’s deadly heatwave in North America (see page 10) is far from the first extreme weather event to shake the world. Apocalyptic blazes hit California last year and Australia in late 2019. Climate attribution studies show that both earlier events were made more likely by climate change. We hardly need the verdict on the North American heatwave to tell us the risks of continued inaction. Yet that it is what we are getting. Despite the damage and loss of life, Australia’s fires barely shifted the political dial for national action on carbon emissions. It seems unlikely that Lytton’s destruction will…

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delta on the rise globally

THE highly infectious delta coronavirus variant is continuing to spread around the world, causing rising case numbers even in countries with high vaccination rates. Some countries that kept previous variants under control are struggling to contain delta, such as Thailand and Vietnam. Some nations are imposing fresh restrictions to curb delta’s spread, including Iran and Indonesia. But others are relaxing restrictions. Despite soaring case numbers, England is set to end almost all restrictions on 19 July. The health secretary, Sajid Javid, warned on 5 July that case numbers could reach 100,000 per day as a result, but wouldn’t say how many deaths the government expected. The decision to end almost all restrictions at once – including the legal requirement to wear face coverings on public transport – has been criticised. It is…

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the heat is on out west

THERE is no question that the drought and recent heat across the western US is bad. Unseasonably high temperatures baked Washington and Oregon, with new highs of 41.7°C in Seattle on 28 June and 44.4°C in Portland on 27 June. Canada, better equipped for blizzards, also suffered in a deadly, record-breaking heatwave. A dry winter means exceptional and severe drought now blankets large swathes of the western US states, with hot summer months still to come – leading to worries of another potentially disastrous wildfire season. The drought is intense even for a region that played host to part of a historic six-year drought starting in 2011. “It’s extraordinarily bad already,” says Peter Gleick at the Pacific Institute in Oakland, California. Spectacularly dry conditions don’t guarantee a wildfire season worse than last…

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what is a heat dome?

The heatwave in Canada may have killed hundreds of people as temperatures broke national records, reaching a high of 49.6°C in Lytton, British Columbia, on 29 June. The next day, a wildfire burned most of the village. The extreme heat at such a northerly latitude has been linked to a ridge of high pressure, also known as a heat dome. “What that dome does is suppresses convective activity,” says Katharine Hayhoe at the Nature Conservancy, a US non-profit organisation. “Convection is what causes those thunderstorms during warm weather, which bring a lot of rain. The dome also does something else: when a storm comes along and there’s this high-pressure system sitting here, it deflects the storm around.” Together, these cause less rain. “And the less rain you get, the hotter it gets…