Cosmologists have found signs that a second type of dark energy — the ubiquitous but enigmatic substance that is pushing the current Universe’s expansion to accelerate — might have existed in the first 300,000 years after the Big Bang.
Two separate studies — both posted on the arXiv preprint server in the past week1,2 — have detected a tentative first trace of this ‘early dark energy’ in data collected between 2013 and 2016 by the Atacama Cosmology Telescope (ACT) in Chile. If the findings are confirmed, they could help to solve a long-standing conundrum surrounding data about the early Universe, which seem to be incompatible with the rate of cosmic expansion measured today. But the data are preliminary and don’t show definitively whether this form of dark energy really existed.
Lukoye Atwoli, Abdullah H Baqui, Thomas Benfield, Raffaella Bosurgi, Fiona Godlee, Stephen Hancocks, Richard Horton, Laurie Laybourn-Langton, Carlos Augusto Monteiro, Ian Norman, Kirsten Patrick, Nigel Praities, Marcel G M Olde Rikkert, Eric J Rubin, Peush Sahni, Richard Smith, Nicholas J Talley, Sue Turale & Damián Vázquez
The UN General Assembly in September, 2021, will bring countries together at a critical time for marshalling collective action to tackle the global environmental crisis. They will meet again at the biodiversity summit in Kunming, China, and the UN Climate Change Conference of the Parties (COP26) in Glasgow, UK. Ahead of these pivotal meetings, we—the editors of health journals worldwide—call for urgent action to keep average global temperature increases below 1·5°C, halt the destruction of nature, and protect health. Health is already being harmed by global temperature increases and the destruction of the natural world, a state of affairs health professionals have been bringing attention to for decades.1 The science is unequivocal; a global increase of 1·5°C above the pre-industrial average and the continued loss of biodiversity risk catastrophic harm to health that will be impossible to reverse.2, 3 Despite the world’s necessary preoccupation with COVID-19, we cannot wait for the pandemic to pass to rapidly reduce emissions.
What is a derecho? An atmospheric scientist explains these rare but dangerous storm systems
Thunderstorms are common across North America, especially in warm weather months. About 10% of them become severe, meaning they produce hail 1 inch or greater in diameter, winds gusting in excess of 50 knots (57.5 miles per hour), or a tornado.
The U.S. recently has experienced three rarer events: organized lines of thunderstorms with widespread damaging winds, known as derechos.
Derechos occur mainly across the central and eastern U.S., where many locations are affected one to two times per year on average. They can produce significant damage to structures and sometimes cause “blowdowns” of millions of trees. Pennsylvania and New Jersey received the brunt of a derecho on June 3, 2020, that killed four people and left nearly a million without power across the mid-Atlantic region.Read More »
There is a huge tectonic place below the land mass of India known as “Indian Plate.” The rotation of the earth is causing this plate to continually move northward just like any matter moves to the top in a centrifugal machine. The Indian Plate crashes into the Tibetan Plate as it moves to the north. The pressure between these two plates is leading to the continual rise of the Himalayas and also earthquakes in Uttarakhand in particular. Thus, Uttarakhand has been having an earthquake every ten years leaving aside the last 20 years. A possible reason for earthquake not taking place in the recent period could be that the load of water in the Tehri Reservoir is acting like a cushion between the two plates just as two boxers stop for a moment if a small child stands between them. However, the Indian Plate continues to push against the Tibetan Plate despite this cushion. Consequently, a bigger earthquake may take place in the coming time.Read More »
During the 24th Western Monarch Thanksgiving Count, nearly 100 volunteers donned their masks and practiced social distancing to carefully survey groves of trees on the California and Northern Baja coast for monarch butterflies. Despite the challenges of conducting field work during a pandemic, volunteers surveyed 246 sites, three more sites than last year. Unfortunately, to the surprise and dismay of many, only 1,914 monarchs were counted at all the sites. This is a shocking 99.9% decline since the 1980s.
The Western Monarch Thanksgiving Count has been done every year since 1997. It happens during the three-week period centered on Thanksgiving and is coordinated by the Xerces Society and Mia Monroe. It is the primary way that the western monarch population is assessed and has built up a body of data than demonstrates the long-term collapse of the monarch migration in western North America.Read More »
Nature is under siege. In the last 10,000 y the human population has grown from 1 million to 7.8 billion. Much of Earth’s arable lands are already in agriculture (1), millions of acres of tropical forest are cleared each year (2, 3), atmospheric CO2 levels are at their highest concentrations in more than 3 million y (4), and climates are erratically and steadily changing from pole to pole, triggering unprecedented droughts, fires, and floods across continents. Indeed, most biologists agree that the world has entered its sixth mass extinction event, the first since the end of the Cretaceous Period 66 million y ago, when more than 80% of all species, including the nonavian dinosaurs, perished.Read More »
The Nature’s 10 list explores key developments in science this year and some of the people who played important parts in these milestones. Along with their colleagues, these individuals helped to make amazing discoveries and brought attention to crucial issues. Nature’s 10 is not an award or a ranking. The selection is compiled by Nature’s editors to highlight key events in science through the compelling stories of those involved.
Tedros Adhanom Ghebreyesus: Warning the world
The public-health leader faced challenges from all sides in trying to rally the globe against COVID-19.
BY SMRITI MALLAPATY
On 15 April, Tedros Adhanom Ghebreyesus, director-general of the World Health Organization (WHO), found himself in a political windstorm. The day before, US President Donald Trump had said that he would halt funding to the WHO, pending a review of its response to the COVID-19 pandemic and its dealings with China.
But instead of reacting publicly to Trump’s accusations of ‘mismanagement’ and ‘cover-ups’, Tedros described the United States as a “generous friend” and emphasized the agency’s desire to serve every country and every partner during the pandemic.Read More »
Snakebites annually cost India’s citizens the equivalent of 3 million years of health and productivity. That figure, reported at a meeting last month, puts the spotlight on survivors of the bites who are left with disabling conditions such as amputation, kidney disease and severe scarring.
The analysis provides the first estimation of the toll of snakebites on survivors in India. It also confirms an earlier calculation showing that more than half of the world’s snakebite deaths occur in the country — demonstrating the need for greater investment in preventive measures.Read More »
Past the South Summit of Everest and climbing the Cornice Traverse with the Hillary Step in the background. Photo: KARMA TENZING
The height of Mt Everest has grown by 86cm to now measure 8848.86m, the foreign ministers of Nepal and China revealed at a joint virtual live event on Tuesday.
The new measurement of Sagarmatha-Zhumulangma (Mt Everest) was declared by Nepal’s Foreign Minister Pradeep Gyawali in Kathmandu and his Chinese counterpart Wang Yi in Beijing by pressing a crystal ball simultanesouly. The two also exchanged congratulatory messages from Nepali President Bidya Devi Bhandari and Chinese President Xi Jinping to each other.Read More »