Curious Cases Folgen

"What happens to the human voice as we age? If I hear a voice on the radio, I can guess roughly how old they are. But singer's voices seem to stay relatively unchanged as they age. Why is this?" All these questions were sent to curiouscases@bbc.co.uk by Jonathan Crain from Long Island in New York.The Doctors discover how the human voice is produced and listen to how our voice sounds when it emerges from our vocal cords. Acoustic engineer Trevor Cox, author of 'Now You're Talking', explains why German and French babies have a different accent. And neuroscientist Sophie Scott describes what happens when boys' voices break, and why a similar thing can happen to women during the menopause.Finally, our voices often change dramatically in later life, as demonstrated by impressionist Duncan Wisbey from Radio 4's Dead Ringers. Expect cameos from David Attenborough, Dumbledore and Paul McCartney.Presenters: Hannah Fry, Adam Rutherford Producer: Michelle Martin.

"What is the fifth dimension?" asks Lena Komaier-Peeters from East Sussex.Proving the existence of extra dimensions, beyond our 3D universe, is one of the most exciting and controversial areas in modern physics. Hannah and Adam head to CERN, the scientific cathedral for quantum weirdness, to try and find them.Theoretical physicist Rakhi Mahbubani explains why we think that dimensions beyond our own might exist. Adam meets Sam Harper, who has spent 14 years hunting for an elusive particle called the 'graviton', which could provide a portal to these extra dimensions. But if they exist, where have these extra dimensions been hiding? Sean Carroll from Caltech explains various ideas that have been dreamt up by physicists, from minuscule hidden planes to gigantic parallel worlds.Producer: Michelle Martin Presenters: Hannah Fry, Adam Rutherford.

"How do we measure the age of the Universe?" asks Simon Whitehead.A hundred years ago this wouldn't even have been considered a valid question, because we didn't think the Universe had a beginning at all. Even Einstein thought that space was eternal and unchanging.This is the tale of how we discovered that the Universe had a beginning, and why calculating its age has been one of the greatest challenges in modern astronomy. We also uncover the mysterious dark energy that pervades the cosmos and discover why it's been putting a scientific spanner in the works.Helping to unravel today's question are physicists Andrew Pontzen, Jo Dunkley and Jim Al-Khalili.Presenters: Hannah Fry, Adam Rutherford Producer: Michelle Martin.