What the scientists are saying…

Why false news spreads fastest False news travels much faster online than the truth – and it’s all because of our craving for novelty. In the largestever study looking at how news spreads on social media, researchers at the Massachusetts Institute of Technology analysed 126,000 stories on Twitter from between 2006 and 2017. They found that false stories were 70% more likely to be retweeted than those that were true, and that true stories took six-times longer, on average, to reach an audience of 1,500 people. One surprise was that automated robots – or bots – played no part in this discrepancy. “False news spreads more than the truth because humans, not robots, are more likely to spread it,” said the authors of the study, which was published in the journal Science. They concluded that the high visibility of false stories is not necessarily the result of malign intent: fake news may get shared more than the truth simply because people find it more surprising or intriguing than the truth. “False news is more novel, and people are more likely to share novel information,” said co-author Professor Sinan Aral.

Getting power from raindrops Solar panels are all very well – but what if it’s raining? Scientists in China have addressed that problem and come up with a solution: a device that generates electricity from both sunlight and raindrops. Like all solar panels, it contains a photovoltaic cell, but on top of this are two transparent polymer layers, one of which acts as an electrode. When raindrops fall on these layers and slide off, the friction generates a static electricity charge. At present, the raindrops don’t provide enough power to make the machine commercially viable, but the researchers hope to rectify this problem within five years. Devices that generate electricity from kinetic energy – triboelectric nanogenerators – are attracting growing interest. Professor Baoquan Sun, a co-author of the study, said his team at Soochow University is also working on “electronic clothes”, which convert their wearer’s body movements into electricity.

The body of a 20-year-old... at 70 Septuagenarians can have bodies virtually indistinguishable from those of people decades younger – providing they commit to a lifetime of strenuous exercise. To determine if regular exercise slows down ageing, scientists at the University of Birmingham recruited 125 amateur cyclists aged between 55 and 79, all of whom had pursued the hobby for 25 years or more, and covered 300km every month. The group underwent a series of tests, and their results were compared with adults of varying ages who didn’t exercise regularly, but were otherwise healthy. On a range of physical measures – including muscle mass, body fat and cholesterol – the cyclists were found to have avoided the changes usually associated with ageing. More surprisingly, their immune systems didn’t appear to have weakened either: even in their 70s, they were still producing as many T cells – specialised immune cells that help organise the body’s response to infection – as would a much younger person. “It’s amazing,” co-author Professor Janet Lord told The Times. “If you put a bag on their heads and just showed people their bodies you would think they were 20-year-olds.” But you may not need to be a super-cyclist to get such benefits, she said. “My suspicion is you don’t need to do a massive amount [of exercise]. It may be intensity that helps – going up and down the stairs ten times a day.”

Keep fit to ward off dementia Keeping fit in middle age can slash a woman’s risk of developing dementia by almost 90%. For a study conducted at the University of Gothenburg, 191 women aged 38 to 60 were asked to ride an exercise bike as hard as they could, to gauge their cardiovascular fitness. Based on the results, they were then divided into three groups – 40 were classed as very fit, 92 as fairly fit and 59 as low fitness. Four decades later, only 5% of the most fit women had dementia, rising to 32% of the least fit. Moreover, the few very fit women who did get dementia only became symptomatic aged 90, on average – 11 years later than the moderately fit patients. The study was small, and it does not prove causality, but it adds to a growing body of evidence that exercise is one of the best ways of warding off the disease.