This week, what happened to the Wankel Rotary Engine; why does air become thinner at altitude and thicker at depths; and why do I need to blow my nose vigorously when I first wake up but not at other times of the day? Also, what are the best pollinators, what's the evidence for macro-evolution, why do many great discoveries get discovered at the same time by independent workers, and what happens in the brain during hypnosis. Join Dr Chris and Lester Kiewit for the answers... Like this podcast? Please help us by supporting the Naked Scientists