This week, Dr Chris and Dr Helen explore the microscopic world, finding out why diarrhoea and projectile vomiting make cruise ships the perfect culture vessel for noroviruses, and asking why fungi are so important for great tasting chocolate. Also, we look at giving yeast a sense of smell, predict the weather for a planet 63 light years away, and size up the world's smallest scales, which are capable of weighing a single bacterium. Meanwhile, in Kitchen Science, we looked at toilet seats and kitchen surfaces to see which harboured the most bacteria, and came in for a nasty surprise! Like this podcast? Please help us by supporting the Naked Scientists)