Discovery

A story of sorrow and comfort today, as Doctors Adam Rutherford and Hannah Fry investigate two mysteries sent in by listeners.The Psychic Tear Edith Calman challenges our scientific sleuths to answer the following question: “What is it about extreme pain, emotional shock or the sight of a three-year-old stumbling their way through an off-key rendition of Away in a Manger that makes the brain send messages to the lacrimal glands to chuck out water?"Hannah discovers how the eye produces tears, with the help of Dr Nick Knight. Broadcaster Claudia Hammond, author of Emotional Rollercoaster, describes why Darwin experimented on his children until they cried. And, Adam watches a tearjerker to take part in a psychological study, but ends up getting angry instead.The Tea Leaf Mystery The team examine how to make the perfect cup of British tea, in response to Fred Rickaby from North Carolina: "When we are preparing a cup of tea and the cup contains nothing but hot, brewed tea we need to add milk and sugar. My wife alw