#255Why do some people seem to be naturally immune to covid-19? We may finally have the answer and it’s to do with differences in the way immune cells function. Will the finding help us predict who’s immune and who isn’t – and more?Artificial intelligence is being used to tackle the problem of clearing mines from enormous swaths of Ukraine. Russia has scattered vast amounts of ordinance across Ukraine, tearing up agricultural land and leaving behind chemical contamination. The clean-up operation could take 700 years to complete in total. AI is helping Ukraine to work out where to start.Chimpanzees are herbal medicine enthusiasts: when sick, they seem to seek out specific plants. But how effective are the plants they’re swallowing at actually dealing with illness? Wild chimps in Uganda’s Budongo Forest are helping researchers to understand the practice.Maxwell’s demon, a thought experiment that involves a tiny imp, was once thought to disprove the second law of thermodynamics. Now researchers have built a real-life Maxwell’s demon that is not only the largest of its kind so far but could be used to discover new drugs and clean CO2 from the air.Plus: Leeches can jump and we’ve finally seen them do it; why cashew nuts could help us decarbonise shipping; and do the methane seas of Saturn's moon Titan have waves that erode their shorelines?Hosts Timothy Revell and Christie Taylor discuss with guests Alexandra Thompson, Matthew Sparkes, Sam Wong and Alex Wilkins.To read more about these stories, visit newscientist.com. Hosted on Acast. See acast.com/privacy for more information.