Do planes change the weather?

How do flu jabs really work? Should you refrain from sex before a sports competition? Why don't we sneeze when we're sleeping? Could we use stem cell therapy to cure autism? Is it better to drink beer made from natural products or fizzy drinks with sweeteners? What's crystalline folliculitis? Are all antibiotics variations of the same thing? How many blades do you need to get a clean shave? Like this podcast? Please help us by supporting the Naked Scientists