Science

Did the cosmos arise out of a big bounce from another universe?Vadim Sadovski/Shutterstock Could our universe be expanding and shrinking back into a tiny point, reliving a kind of big bang over and over again? Probably not, according to a mathematical analysis that argues that the laws of physic forbid such a cyclic universe. A key moment in the life of a cyclic universe is the big bounce, an alternative to the big bang as the beginning of the known universe. The big bang starts with a singularity – matter and energy packed into a point so dense that gravity becomes strong enough to elude the laws of physics as we understand them – followed by an endless outwards expansion. But if the universe began with a big bounce, we could look beyond what we think of as the b...

Adapted from a release written by Alison Auld for Dalhousie University Lamont’s R/V Marcus G. Langseth. Credit: Anne Becel A new study published in Science Advances has revealed the first detailed images of a newly developing subduction zone off the coast of British Columbia’s Haida Gwaii archipelago. The international team of researchers collected the data for this study during a 2021 cruise by the Lamont-Doherty Earth Observatory’s research vessel, the Marcus G. Langseth. They used a 15-kilometer-long underwater cable equipped with thousands of underwater microphones, called hydrophones, in the area off northern British Columbia to map the deep structure of the Earth’s subsurface. Their data confirmed that the Queen Charlotte fault system can generate powerful megathrust eart...

In the past two decades, the US President’s Emergency Plan for AIDS Relief (PEPFAR) has prevented millions of deaths and new HIV infections through the provision and support of HIV testing, treatment, and prevention programs in more than 50 countries worldwide (1). Although HIV remains incurable, treatment with antiretroviral therapy (ART) leads to sustained viral suppression, which halts both immune system destruction and HIV transmission (2–4). With ART delivery at its core, PEPFAR has been enormously successful in improving both individual and public health: At the end of 2024, more than 20 million people were receiving life-saving ART through PEPFAR, and between 2010 and 2023, new HIV infections were reduced by an estimated 52% in PEPFAR-supported countries (1). However, in January, th...

AI could automate some government paperwork, but it comes with serious risksBrett Hondow / Alamy Many countries are exploring how artificial intelligence might help with everything from processing taxes to determining welfare benefits. But a survey shows citizens are not as enthusiastic as their governments – and this can create real risks for democracy. “Focusing only on short-term efficiency gains and shiny technology risks triggering public backlash and contributing to a long-term decline in democratic trust and legitimacy,” says Alexander Wuttke at the Ludwig Maximilian University of Munich in Germany. Wuttke and his colleagues asked around 1200 people in the UK to share their feelings about government actions where either a human or an AI handled the task. Th...

Dozens of storm-chasing meteorologists have undertaken the largest-ever study of extreme hail across the US Great Plains. New Scientist environment reporter James Dinneen hitched a ride inside a fortified truck called the Hail Hunter to get an inside view of the campaign during one of the most extreme hailstorms to affect the Texas panhandle on 5 June. The project, known as ICECHIP, collected more than 10,000 hailstones over 42 days, as well as huge volumes of data on virtually every aspect of the storms that produced them. The largest stone they collected was 149 millimetres in diameter, about the size of a large grapefruit. Such hailstones can be extraordinarily destructive. Every year, extreme hailstorms in the US cause ...