This week on Ask the Naked Scientists we answer your questions on population, sonic booms and fuel. We'll be looking into the genes behind your eye colour, why planes are so noise when they go supersonic and how exactly we get our beloved petrol and diesel from its original source-crude oil. We'll also be investigating the best time to walk your dog, why the South Pole is colder than the North Pole and how a collision with our earth created our moon. All that and more of your questions answered on this week's podcast. Like this podcast? Please help us by supporting the Naked Scientists