Can we break glass using sound? Is glass a liquid? Can we use GPS to navigate galaxies? Will climate change make the UK colder by affecting the Gulf stream? We tackle these questions on this weeks show as well as reveal how submarines stay at a fixed depth,why toothpase is better with fluoride in it, how sunlight can be converted into energyand we investigate whether we could ever create a time machine! Like this podcast? Please help us by supporting the Naked Scientists