Curious Cases

"What's inside a black hole and could we fly a spaceship inside?" asks Jorge Luis Alvarez from Mexico City.Some interstellar fieldwork is on the agenda in today's Curious Cases. Astrophysicist Sheila Rowan explains how we know invisible black holes actually exist. And cosmologist Andrew Pontzen is on hand to help cook one up.But which of our intrepid doctors will volunteer to fly into the heart of a black hole?You can send your Curious Cases for the team to investigate to: curiouscases@bbc.co.ukPresenters: Hannah Fry, Adam Rutherford Producer: Michelle Martin.

"How on earth do cats find their way back to their previous home when they move house?" asks Vicky Cole from Nairobi in Kenya. Our enduring love for our feline friends began when Egyptian pharaohs began to welcome domesticated moggies into their homes. Pictured reclining in baskets at the feet of royalty, pet cats soon became fashionable throughout society in Egypt.Today they are the most popular pet in the world, and home is definitely where their hearts lie."Whereas dogs are bonded to people, cats are bonded to place," explains zoologist Dr John Bradshaw. "It's very typical for them to try and find their way back to their old house when you move."But how do they do it? And if their navigational skills are so good, why do they get lost?Plus, Prof Matthew Cobb reveals the super-senses that cats possess, which humans don't, and how to spot when your cat is deploying them.You can send your Curious Cases for the team to investigate to: curiouscases@bbc.co.ukPresenters: Hannah Fry, Adam Rutherford Producer: Michelle Martin.

"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.

"Why does the Earth spin?" asks Joe Wills from Accra in Ghana. Hannah quizzes cosmologist Andrew Pontzen about the birth of the Solar System and why everything in space seems to spin. Is there anything in the Universe that doesn't revolve?BBC weatherman John Hammond explain to Adam how the rotation of the Earth creates our weather systems and the strange things that would happen if we spun the opposite way.Send your Curious Cases for consideration to: curiouscases@bbc.co.ukPresenters: Hannah Fry, Adam Rutherford Producer: Michelle Martin.

"Science tells us that our body houses microbial organisms. Then how much our weight is really our weight? If I am overweight, is it because of my own body cells or excess microflora?" asks Ajay Mathur from Mumbai in India.Adam bravely sends off a sample to the 'Map My Gut' project at St Thomas' Hospital to have his microbes mapped. Prof Tim Spector reveals the shocking results - a diet of fried breakfasts and fizzy drinks has left his guts in disarray. But help is at hand to makeover his bacterial lodgers.Science writer Ed Yong, author of 'I Contain Multitudes', reveals how much our microbes weigh. We're just beginning to discover the vast array of vital functions they perform, from controlling our weight, immune system and perhaps even influencing our mood and behaviour.Send your Curious Cases for consideration to: curiouscases@bbc.co.ukPresenters: Hannah Fry, Adam Rutherford Producer: Michelle Martin.

Why do some people have a terrible sense of direction? The team receive a mysterious message from an anonymous listener who constantly gets lost. Can they help her find the answer?This listener may, or may not, be the team's producer, Michelle. She would like to state that it's not her fault that she has been dealt a bad genetic hand which has led to faulty place cells developing in her brain. And head direction cells that appear to be pointing the wrong way. More understanding should surely be afforded to those who are navigationally challenged.Hugo Spiers from University College London, has devised a free game called 'Sea Hero Quest' which anyone can use to test their navigational skills. Plus Catherine Loveday from the University of Westminster suggests strategies to help those who tend to get lost.If you have any Curious Cases for us to solve please email curiouscases@bbc.co.ukPresenters: Adam Rutherford & Hannah Fry Producer: Michelle Martin.

'A teacher I work with swears that around the time of the full moon kids are rowdier in the classroom, and more marital disharmony in the community," says Jeff Boone from El Paso in Texas. 'Is there any biological reason why the moon's phases could affect human moods and behaviour?'Our scientific sleuths sift through the evidence to find out if the moon really does inspire lunacy. They consider Othello's testimony, a study on dog bites and homicides in Florida before coming to a conclusion based on current scientific evidence.Featuring neuroscientist Eric Chudler from the University of Washington and health broadcaster and author Claudia Hammond.If you have any Curious Cases for the team to solve please email curiouscases@bbc.co.ukPresenters: Adam Rutherford & Hannah Fry Producer: Michelle Martin.

In the last episode the team started investigating the following inquiry, sent in to curiouscases@bbc.co.uk: 'Is there any such thing as nothing?'They discovered why quantum fluctuations and the Higgs field mean that nothing is impossible. But how about in mathematics?The story of zero is fraught with inspiration, competition and controversy. Banned in Florence and hated by the Church, zero had a rocky road to acceptance after its genesis in India.Hannah talks to author Alex Bellos and hears about his journey to India to see the birth of zero, featuring archive from 'Nirvana by Numbers' on BBC Radio 4.Plus, Adam is sent on a mission to understand calculus and enlists the help of Jeff Heys from Montana State University.If you have any Curious Cases for the team to solve please email curiouscases@bbc.co.ukPresenters: Adam Rutherford & Hannah Fry Producer: Michelle Martin.