Has all the air in the world been breathed before? Are any viruses beneficial to health? Can naked farts transmit diseases? You set the agenda in this Naked Scientists Question and Answer show in which we also discover how Inuit cope without fruit and veg, whether muscles can become cancerous and how long before we can teleport to work. Plus, reproducing Alzheimer's disease in a dish, self-distilling vodka, magnetic soap to cleanse the parts other soaps can't reach, and what magic mushrooms do to the brain...