On the Naked Scientists news podcast, 'muscles on chips' provide microgravity researchers new opportunities to study ageing. Also in the show, the machine learning models overhauling weather forecasting, and scientists unpick how the placebo effect reduces pain by discovering the brain network responsible. Then, we speak to a doctor on how to protect yourself from skin cancer in the summer, and we find out what it is we can smell when it rains and where you are most likely to smell it. Like this podcast? Please help us by supporting the Naked Scientists