There are four fundamental forces that describe how everything works, from black holes to radioactive decay to sounds coming out of your headphones. But this week we discuss hints that there is a fifth fundamental force of nature.In the pod this week are New Scientist journalists Rowan Hooper, Penny Sarchet, and Valerie Jamieson. They ask whether physics is in crisis, given that it struggles to explain 95% of the universe, or if physicists are happy, because there is so much still to discover. The team also discuss the creation of mouse-human chimeras, they reveal how kelp could help remove billions of tonnes of carbon from the atmosphere, and analyse whether dystopian science fiction has primed us to think that social distancing surveillance measures - such as the robot dog seen patrolling in Singapore - are too creepy. And there’s a swift discussion about the bird that sleeps on the wing and that has just returned to Europe from Africa. To find out more, subscribe at newscientist.com/podcasts.Join our online event: ‘Can we trust the science?’ on Monday 18 May at 6pm BST here: https://www.newscientist.com/science-events/new-online-series-continues-coronavirus-can-trust-science/ Our GDPR privacy policy was updated on August 8, 2022. Visit acast.com/privacy for more information.