Dr Chris and Clarence Ford take on listener questions. This time they include, is intelligence more nature or nurture? Is time travel possible? Could time travellers be walking among us? Are Tibetan monks really capable of levitating? Why do I feel down during the holidays? What are the differences between lab grown and mined diamonds? What are weeds and why do they always grow where they shouldn't? Like this podcast? Please help us by supporting the Naked Scientists