This week - How do glow worms glow, and can they do so indefinitely? Why don't birds fall out of trees when they sleep? And space tourism: when can I book my ticket to orbit? We've assembled an expert panel to answer your science questions - Richard Hollingham, space and science journalist; Keziah Latham, optometrist; Peter Cowley, tech investor, and Sophie Mowles, behavioural ecologist. Like this podcast? Please help us by supporting the Naked Scientists