Why should milk 'change it's tune' when it's being steamed? In this Question of the Week, we find out why the sound of steaming milk changes abruptly at around 60C (140F), and invite you to consider Sir David Attenborough's question for next week... Like this podcast? Please help us by <a href="https://www.thenakedscientists.com/donate">supporting the Naked Scientists</a>

The Many Shapes of Leaves

Each week we set out to solve one of the world's weirdest, wackiest, funniest and funkiest scientific puzzles. And along with the answer there's a brand new question to think about for next time...