This week, we're investigating alternatives to petrol. We'll board a biofuel powered bus to meet the plant scientists who are using algae to make biodiesel. We'll find out how to turn household waste into hydrogen, and meet the brains behind Bristol's first hydrogen powered passenger boat! Plus, the brain basis of boundless optimism, why a bacteria-busting chemical keeps injured arteries open, and a run down of this year's Nobel prizes! Like this podcast? Please help us by supporting the Naked Scientists)