Some social media users have been pouring milk down the drain and chucking their butter in the bin in protest over a new additive in cow feed that claims to reduce methane emissions. The online posts, attacking Arla Food’s trial of Bovaer with three big supermarkets and 30 farms in the UK, have had millions of views. So, what do we know – what is this additive and how is it going to tackle burpy cows? And what is the evidence it is safe? We interrogate the science with Sharon Huws, professor in animal science, and food scientist Dr Stuart Farrimond... Also this week, are billionaires really deserting Earth for space? What is the upshot for our plastic waste problem after global talks on a treaty ended in failure? And why, just why, are orcas being spotted wearing salmon hats? Presenter: Victoria Gill Producers: Sophie Ormiston, Ella Hubber & Gerry Holt Editor: Martin Smith Production Co-ordinator: Jana Bennett-Holesworth To discover more fascinating science content, head to bbc.co.uk search for BBC Inside Science and follow the links to The Open University.