Curious Cases Folgen

"Why do we have different blood types?" asks Doug from Norfolk.The average adult human has around 30 trillion red blood cells, they make up a quarter of the total number of cells in the body. We have dozens of different blood groups, but normally we're tested for just two - ABO and Rhesus factor. Adam and Hannah delve into the gory world of blood and the early history of blood transfusions, to discover why we have blood groups and what makes them so important.Featuring interviews with Dr Jo Mountford, from the Scottish National Blood Transfusion Service and immunologist Dr Sheena Cruikshank from the University of Manchester.Send your Curious Cases for consideration to: curiouscases@bbc.co.ukPresenters: Hannah Fry, Adam Rutherford Producer: Michelle Martin.

"Why don't we remember the first few years of our lives?" asks David Foulger from Cheltenham.The team investigate the phenomenon of 'infant amnesia' and how memories are made with Catherine Loveday from the University of Westminster.A whopping 40% of people say they can remember back to before they were two years old, and 18% can recall being babies. But can we really trust these early memories? Martin Conway from City University discusses his latest findings, taken from data gathered during 'The Memory Experience' on BBC Radio 4.Presenters: Hannah Fry, Adam Rutherford Producer: Michelle Martin.

"How far up can a helium balloon go? Could it go out to space?" asks Juliet Gok, aged 9.This calls for some fieldwork! Adam travels to the Meteorology Department at the University of Reading where Dr Keri Nicholl helps him launch a party balloon and track its ascent. But this experiment doesn't quite go to plan.Meanwhile, Hannah consults Public Astronomer Dr Marek Kukula, from the Royal Observatory Greenwich, to discover where space begins. And she decides to take matters into her own hands, with the help of a helium canister and some trusty equations, to help answer Juliet's question.Send your Curious Cases for consideration to: curiouscases@bbc.co.ukPresenters: Hannah Fry, Adam Rutherford Producer: Michelle Martin.