Do stars form outside galaxies? What causes ringing in the ears? How fast does force propagate? Why do spectacles still work when worn backwards? Is the expanding universe tearing galaxies apart? And is any new water being created on Earth? Plus, news of the new satellite surveying the moon, the scientific way to sound out a Stradivarius and how a vaccine based on chimp viruses can protect against Hepatitis C. Plus, in kitchen science, Dave unpacks the contents of a nappy...