"How fast can a human run and would we be faster as quadrapeds?" This question flew in via Twitter from Greg Jenner.
Is there a limit to human sprinting performance? In this episode we investigate the biomechanics of running, statistical trends in human performance and which kind of monkey runs the fastest.
But first, an experiment. Due to some spurious and possibly fictional injuries, neither Hannah nor Adam are fit enough to take part in a sprint trial at the University of Bath. So long-suffering Producer Michelle steps up to the challenge and into the starting blocks. Not known for her love of athletics, or exercise of any sort, how will she fair in the ultimate speed test?
Biomechanist Peter Weyand from Texas discusses the role of different muscle types in speed versus endurance. Sports scientist Polly McGuigan reveals why Usain Lightning Bolt is still the fastest man in the world. And Prof of Sports Engineering Steve Haake reveals how fast a man can run like a monkey.
"Why do people experience pain differently when they go through the same event?" asks Claire Jenkins from Cwmbran in Wales.
Professor of Pain Research, Irene Tracey, welcomes Adam in to the room she calls her 'Torture Chamber'. Burning, electrocuting, lasering and piercing are all on the menu, but which will hurt the most?
Hannah speaks to Steve Pete from Washington who has a rare genetic condition which means he does not feel pain. For chronic sufferers, this sounds like heaven, but a life without pain has brought untold suffering to him and his family, including the tragic story of his brother, Chris.
We look at how the body creates pain, why some people feel it more than others, and how this knowledge could help scientists treat pain more effectively in the future.
Presenters: Hannah Fry, Adam Rutherford
Producer: Michelle Martin
(Photo: A runner beats the pain to make it over the finishing line in the Hong Kong Marathon 12 February 2006. Credit: Martin Chan/South China Morning Post/Getty Images)
How do instruments make music?
"We play many musical instruments in our family. Lots of them produce the same pitch of notes, but the instruments all sound different. Why is this?" asks Natasha Cook aged 11, and her Dad Jeremy from Guelph in Ontario, Canada.
In this new series of The Curious Cases of Rutherford and Fry, Hannah and Adam are joined by the Curious Cases band - Matt Chandler and Wayne Urquhart - to play with today's question.
Bringing the science we have acoustic engineer and saxophone player Trevor Cox. Plus materials expert Zoe Laughlin demonstrates a selection of her unusual musical creations, including a lead bugle, a glass bell and a spruce tuning fork.
Presenters: Adam Rutherford, Hannah Fry
Producer: Michelle Martin
Main image: 1-25 Wind instruments, 26-34 percussion instruments, Egypt, engraving by Duhamel from Description of Egypt, or the collection of observations and researches which were made in Egypt during the expedition of the French Army), Etat moderne, Planches, Volume II, Plate PlCC, Imprimerie Imperiale, 1817, Paris. Credit: De Agostini Editorial / Getty Images
A sense of time
Our senses create the world we experience. But do animals have a ‘sense’ of time, and does that differ between species, or between us and other animals?
We know that animal senses reveal a wealth of information that humans can't access. Birds can see in ultra violet, and some fish can 'feel' electricity. So perhaps their sense of time is similar.
If you've ever tried to swat flies, you'll know that they seem to have super-powered reactions that let them escape before you can blink. Presenter Geoff Marsh asks whether flies have some sort of super-power to see the world in slow motion. Are they watching your hand come down at what might appear a leisurely pace?
Science reveals a window into the minds of different species and their temporal perceptions. Some birds have such fast vision that they can see and react to movement at twice the speed you can, and our vision works at more than six times the speed of one species of deep sea fish. This programme delves into each moment of experience to ask 'what is time, biologically?' When birds have to dodge through forests and catch flies on the wing, or when flies have to avoid those birds, it would seem that a faster temporal resolution would be a huge advantage.
Geoff meets physicist Carlo Rovelli and asks him to jump outside of physics to answer questions on biology and philosophy. Geoff explores the mind of a bat with Professor Yossi Yovel in Israel, and dissects birdsong at super slow speeds with BBC wildlife sound recordist, Chris Watson. Getting deep into the minds of animals he questions whether our seconds feel like swordfish seconds, or a beetles' or birds' or bats..?
Presenter: Geoff Marsh
Producer: Rory Galloway
Picture: Violaceous Euphonia (Euphonia violacea) male flying from branch, Itanhaem, Brazil
Credit: Getty images
Cat Hobaiter on communication in apes
Dr Catherine Hobaiter studies how apes communicate with each other. Although she is based at the University of St Andrews in Scotland, she spends a lot of her time in the forests of Uganda, at the Budongo Research Centre. There, she is endlessly fascinated by the behaviour of great apes.
Cat Hobaiter tells Jim al-Khalili about the difficulties of carrying out research on chimps in the wild. It can take years to win the trust of the apes. She says that her approach is to adopt the attitude of a moody teenager. Look bored and the chimps will ignore her, but at the same time she is watching them closely. Her particular research area is in understanding not the sounds that apes make, but their gestures. From her observations she has found that they use around 80 different gestures - many of which are common, in the sense that they have the same meaning, across different species like chimps and bonobos. One thing she and her team hope to learn from these studies is how we humans have evolved spoken language.
(Photo: Dr Catherine Hobaiter)
Carlo Rovelli on rethinking the nature of time
Carlo Rovelli is a theoretical physicist who became a household name when his book Seven Brief Lessons on Physics became an unexpected international bestseller. His concise, and poetic, introduction to the laws and beauty of physics has sold more than a million copies. He’s also a pioneer of one of the most exciting and profound ideas in modern physics, called loop quantum gravity.
Carlo Rovelli tells Jim al-Khalili how he first became interested in the nature of time when he took LSD as a young man. Later he became curious about the world of the almost absurdly small, where time has no meaning and space is grainy. He took seven years to complete his undergraduate degree, having spent a lot of time protesting against the political establishment, falling in love and travelling. All this rebelling taught him the value of seeing the world in a different way and the benefits of challenging the status quo. In the end he concluded it was easier, and more meaningful, to challenge Einstein’s understanding of time, than it was to overthrow the government.
Picture: Carlo Rovelli. Credit: BBC
Producer: Anna Buckley