mark lobel, bbc news. the sight of a butterfly taking flight is something lots of us have stopped to look at, but have you ever wondered how such delicate creatures fly? a new study has found butterflies cup and clap their wings to generate thrust which helps them avoid dangerous predators. scientists in sweden used a wind tunnel and high speed cameras to capture the insect s unique flying skill. a p pa re ntly apparently the material is flexible and it forms a pocket of air which claps together which propels even better, so the practical, what is the word i am looking for? i don t know. application the word i am looking for? i don t know. application of the word i am looking for? i don t know. application of that - the word i am looking for? i don t know. application of that is - the word i am looking for? i don t know. application of that is the i the word i am looking for? i don t l know. application of that is the way that drones know. application of that is the way that dron
what had been suspected for half a century, that butterflies don t just flap their wings, but clap them together. theirflexible wings bending to form a cup, or a pocket, of air. when they collapse, this thrust is even stronger and more efficient. it s only now thanks to modern technology and a swedish wind tunnel that we can see it. it s a challenge to work with any living flying animal but with butterflies it s maybe even more because they are smaller, they are fast in their behaviour, difficult to predict their behaviour and also when flying them in a wind tunnel, it s difficult to get them to behave as you want to, when you want to and also to fly where you want them to fly. for a long time, scientists wondered how these creatures could actually avoid predators because of their awkward shape. if you look at their wings, you can see they are very large and broad compared to the size of their body and aren t considered
cuts already, are more sustainable for the bbc if it wants to stick to the ethos it has set out and deliver the ethos it has set out and deliver the programming that it provides to the programming that it provides to the public? tt the programming that it provides to the ublic? , , ., ., the public? it set itself a target of delivering the public? it set itself a target of delivering £800 the public? it set itself a target of delivering £800 million - the public? it set itself a target of delivering £800 million of i of delivering £800 million of savings by 2022 and it is on track. £618 million to date. in the last year, due to covid 19, it has increased its savings targets at £1 billion. redundancies need to be the next part of its programme but it believes that it is going to be difficult to make further savings without having a major impact on audiences and content in the future. thank you very much for that. a study has found butterflies clap
a new insight into one of the mysteries of the natural world, how butterflies fly despite being equipped with large, inefficient wings. they ve discovered that butterflies cup their wings when taking off. this forms an air pocket that pushes the insect forward at speed, helping it to escape predators. researchers believe the knowledge could prove useful in other spheres, such as making some drones and underwater vehicles more efficient. this is bbc world news, the latest headlines: joe biden and kamala harris lead a ceremony to honour the 400,000 americans who ve died during the pandemic. president trump releases a farewell video on his last day in office before issuing his presidential pardons, including one for key former aide steve bannon. netflix got a big boost from the pandemic last year, as demand for streaming movies and television soared. the company now has more than 200 million paid members, up more than 30% from 2019. about 37 million people subscribed last year, including
have a label, is the case for the atrocities being committed against the uighur people in china by the communist party. stay with us on bbc news, still to come: the puzzle of how butterflies fly has been solved and the answer could propel human travel. donald trump is now the 45th president of the united states. he was sworn in before several hundred thousand people on the steps of capitol hill in washington. it s going to be only america first. america first. demonstrators waiting for mike gatting and his rebel cricket team were attacked with tear gas and set upon by police dogs. anti apartheid campaigners say they will carry on the protests throughout the tour.