How To Fall To Earth (Without Burning Up)

Rockets are built to slice cleanly through the atmosphere on the way up. Coming home, it turns out, requires... not turning into a fireball before a bellyflop When Space Shuttles reenter Earth’s atmosphere at 17,000 miles per hour, they don’t dive nose first. Instead they turn broadside to the atmosphere, deliberately creating more drag, more friction, more heat. At those speeds, oncoming air compresses into a shockwave hotter than molten lava. In this episode of Field Notes, Professor Hannah Fry and Michael Stevens explore the strange physics of coming home. Why is leaving Earth easier than returning to it? And what does a small, almost empty black tile reveal about the problem of meeting the world at 17,000 miles per hour? Along the way, they revisit controversial experiments in human fear, calculate which superhero power would bankrupt you in calories, and reflect on the thin boundary between surface and survival. ------------------- For more information about Cancer Research UK, their research, breakthroughs and how you can support them, visit ⁠⁠https://cancerresearchuk.org/restisscience⁠⁠ Cancer Research UK is a registered charity in England and Wales (1089464), Scotland (SC041666), the Isle of Man (1103) and Jersey (247). A company limited by guarantee. Registered company in England and Wales (4325234) and the Isle of Man (5713F). Registered address: 2 Redman Place, London, E20 1JQ. ------------------- Find The Rest Is Science all over the internet by ⁠⁠clicking here.⁠⁠ ------------------- Video Producer: Adam Thornton + Oli Oakley Video & Social: Bex Tyrrell Assistant Producer: Imee Marriott Senior Producer: Lauren Armstrong-Carter Head Of Digital: Samuel Oakley Exec Producer: Neil Fearn Learn more about your ad choices. Visit podcastchoices.com/adchoices

If someone asked you to point to yourself, where would you point? Your chest? Your head? Somewhere just behind your eyes? Where are you? In this episode, Professor Hannah Fry and VSauce’s Michael Stevens explore how the brain maps and understands out location, from the inner ear fluid that tells us which way is up, to the grid and place cells that build a kind of internal GPS. But how do London taxi drivers rewire their brains to memorise entire cities when the rest of us can’t? How does language change the way we orient in space? And what happens when your senses disagree about your where in the world you are? Moving from avalanches and virtual reality to ancient philosophy and modern neuroscience, Hannah and Michael move from how to find ourselves on a map to how locating the “self” inside the body may be one of the deepest mysteries in science. Why did Aristotle believe the self lived in the heart instead of the head? If we’re asked to find the self where do we point? What does it mean to say that you are somewhere…at all? ------------------- For more information about Cancer Research UK, their research, breakthroughs and how you can support them, visit ⁠⁠https://cancerresearchuk.org/restisscience⁠⁠. Cancer Research UK is a registered charity in England and Wales (1089464), Scotland (SC041666), the Isle of Man (1103) and Jersey (247). A company limited by guarantee. Registered company in England and Wales (4325234) and the Isle of Man (5713F). Registered address: 2 Redman Place, London, E20 1JQ. ------------------- Find The Rest Is Science all over the internet by ⁠⁠clicking here.⁠⁠ ------------------- Video Producer: Adam Thornton + Oli Oakley Video & Social: Bex Tyrrell Researcher: Hannah Dodd-Vastiau Assistant Producer: Imee Marriott Senior Producer: Lauren Armstrong-Carter Head Of Digital: Samuel Oakley Exec Producer: Neil Fearn Learn more about your ad choices. Visit podcastchoices.com/adchoices

At what exact chemical ratio does our beloved chocolate devolve into a mere structure of fats and sugars? How far can you dilute chocolate before its fundamental identity vanishes? And what could a comically tiny novelty stool possibly reveal about Michael Stevens? Unlike a block of pure iron or a vial of chlorine, chocolate is not one single substance but a complex and heterogeneous mixture we all take for granted. Hannah and Michael explore the chemistry and nutritional boundaries of this everyday treat. Where does the stool come in? You'll have to listen to find out. ------------------- For more information about Cancer Research UK, their research, breakthroughs and how you can support them, visit ⁠⁠https://cancerresearchuk.org/restisscience⁠⁠ Cancer Research UK is a registered charity in England and Wales (1089464), Scotland (SC041666), the Isle of Man (1103) and Jersey (247). A company limited by guarantee. Registered company in England and Wales (4325234) and the Isle of Man (5713F). Registered address: 2 Redman Place, London, E20 1JQ. ------------------- Find The Rest Is Science all over the internet by ⁠⁠clicking here.⁠⁠ ------------------- Video Producer: Adam Thornton + Oli Oakley Video & Social: Bex Tyrrell Assistant Producer: Imee Marriott Senior Producer: Lauren Armstrong-Carter Head Of Digital: Samuel Oakley Exec Producer: Neil Fear Learn more about your ad choices. Visit podcastchoices.com/adchoices

Is deception a uniquely human trait, or is the natural world built on a foundation of fraud? When a cuttlefish shifts its skin to mimic a female and sneak past a rival male, this may be deceptive but is it telling a lie? Professor Hannah Fry and VSauce's Michael Stevens explore the evolutionary biology of dishonesty across the animal kingdom. What is the neurological difference between a biological reflex and a calculated bluff? What kind of cognitive processing is needed for true artifice, and are human beings the only creatures on earth who possess it? Moving from tactical falsehoods by the Adélie Penguin, to the complex betrayals seen in Macaques and Great Apes, Hannah and Michael apply evolutionary game theory to the wild to evaluate the psychology of false signals and the battle between perception, manipulation, illusion and power. ------------------- For more information about Cancer Research UK, their research, breakthroughs and how you can support them, visit ⁠⁠https://cancerresearchuk.org/restisscience⁠⁠ Cancer Research UK is a registered charity in England and Wales (1089464), Scotland (SC041666), the Isle of Man (1103) and Jersey (247). A company limited by guarantee. Registered company in England and Wales (4325234) and the Isle of Man (5713F). Registered address: 2 Redman Place, London, E20 1JQ. ------------------- Find The Rest Is Science all over the internet by ⁠⁠clicking here.⁠⁠ ------------------- Video Producer: Oli Oakley Video & Social: Bex Tyrrell Researcher: Hannah Dodd-Vastiau Assistant Producer: Imee Marriott Senior Producer: Lauren Armstrong-Carter Head Of Digital: Samuel Oakley Exec Producer: Neil Fearn Learn more about your ad choices. Visit podcastchoices.com/adchoices

Topologically speaking, a human is just a donut with seven holes. It sounds like a joke, but it is a fundamental biological reality. Professor Hannah Fry and Michael Stevens explore the strange geometry of the human body, tracing how we evolved from simple tubes into complex toruses. They investigate the "design flaw" at the boundary of our existence, the fragile transition where skin meets internal lining, and ask why nature built us with so many vulnerabilities to the outside world.But before mapping our topology, Michael and Hannah tackle the instability of knowledge itself. From the suggestion our current physics is almost certainly wrong, to the edges of logic where mathematics fundamentally breaks down. Plus, they unpack the hidden psychology of symmetry: why is the human brain so obsessed with centering pictures, and what does it tell us about how we order our reality?-------------------For more information about Cancer Research UK, their research, breakthroughs and how you can support them, visit ⁠⁠https://cancerresearchuk.org/restisscience⁠⁠Cancer Research UK is a registered charity in England and Wales (1089464), Scotland (SC041666), the Isle of Man (1103) and Jersey (247). A company limited by guarantee. Registered company in England and Wales (4325234) and the Isle of Man (5713F). Registered address: 2 Redman Place, London, E20 1JQ.-------------------Find The Rest Is Science all over the internet by ⁠⁠clicking here.⁠⁠-------------------Video Producer: Adam Thornton + Oli OakleyVideo & Social: Bex TyrrellAssistant Producer: Imee MarriottSenior Producer: Lauren Armstrong-CarterHead Of Digital: Samuel OakleyExec Producer: Neil Fearn Learn more about your ad choices. Visit podcastchoices.com/adchoices

It starts as a friendly challenge: who can name the biggest number? The only rule? Infinity doesn’t count. What follows is a journey through the biggest finite numbers ever imagined. From Archimedes’ grains of sand to Graham’s Number, a sequence so vast it stretches the limits of human comprehension, Professor Hannah Fry and Michael Stevens tumble through this strange landscape of scale, tracing how mathematicians have pushed counting to its absolute edge. But beyond vast calculations, perhaps this is less about numbers and more about us. Why do humans push at the limits of finitude at all? How do we represent the biggest numbers in existence? Why can’t our brains feel the difference between a million, a billion, and a trillion? And when do big numbers affect our ability to empathise with others? ------------------- For more information about Cancer Research UK, their research, breakthroughs and how you can support them, visit ⁠⁠https://cancerresearchuk.org/restisscience⁠⁠ Cancer Research UK is a registered charity in England and Wales (1089464), Scotland (SC041666), the Isle of Man (1103) and Jersey (247). A company limited by guarantee. Registered company in England and Wales (4325234) and the Isle of Man (5713F). Registered address: 2 Redman Place, London, E20 1JQ. ------------------- Find The Rest Is Science all over the internet by ⁠⁠clicking here.⁠⁠ ------------------- Video Producer: Adam Thornton + Oli Oakley Video & Social: Bex Tyrrell Assistant Producer: Imee Marriott Senior Producer: Lauren Armstrong-Carter Head Of Digital: Samuel Oakley Exec Producer: Neil Fearn Learn more about your ad choices. Visit podcastchoices.com/adchoices

Can mathematics ever truly be proven? And can Michael's poetry help you remember some tricky equations? In this episode, Professor Hannah Fry and Michael Stevens answer your questions and take a look at what it means for something to be true in mathematics. Starting with a grand attempt to prove that one plus one equals two, and into Gödel’s theorem that no system of maths can ever fully prove itself, they explore how maths connects to the real world, from an equation that predicts antimatter to the calculations that led to the discovery of Neptune. After the break, Michael shows off a set of limericks written and read by himself. The Rest Is Science: Field Notes is released every Thursday, with Hannah and Michael exploring questions where mathematics, science, and human behaviour meet. ------------------- For more information about Cancer Research UK, their research, breakthroughs and how you can support them, visit ⁠⁠https://cancerresearchuk.org/restisscience⁠⁠ Cancer Research UK is a registered charity in England and Wales (1089464), Scotland (SC041666), the Isle of Man (1103) and Jersey (247). A company limited by guarantee. Registered company in England and Wales (4325234) and the Isle of Man (5713F). Registered address: 2 Redman Place, London, E20 1JQ. ------------------- Find The Rest Is Science all over the internet by ⁠⁠clicking here.⁠⁠ ------------------- Video Producer: Adam Thornton + Oli Oakley Video & Social: Bex Tyrrell Assistant Producer: Imee Marriott Senior Producer: Lauren Armstrong-Carter Head Of Digital: Samuel Oakley Exec Producer: Neil Fearn Learn more about your ad choices. Visit podcastchoices.com/adchoices

Is it possible to make a sport too good? Professor Hannah Fry and Michael Stevens explore how science, data, and optimisation are transforming modern sports improving athletes and teams, while quietly changing how games are played, watched, and understood. From the Tush Push in the NFL and defensive shifts in Major League Baseball, to dirty air in Formula 1, expected goals in Premier League football, and the statistical dominance of seven footers in the NBA, they examine how prediction, probability, and performance analysis reshape decision making on the pitch, the court, and the track. Along the way, they wonder whether the heart of the games we love are defined by 'unnecessary obstacles', how prediction and probability have reshaped decision making, and why humans might enjoy watching messy problems unfold on the pitch much more than optimised solutions. ------------------- For more information about Cancer Research UK, their research, breakthroughs and how you can support them, visit ⁠⁠https://cancerresearchuk.org/restisscience ⁠⁠ Cancer Research UK is a registered charity in England and Wales (1089464), Scotland (SC041666), the Isle of Man (1103) and Jersey (247). A company limited by guarantee. Registered company in England and Wales (4325234) and the Isle of Man (5713F). Registered address: 2 Redman Place, London, E20 1JQ. ------------------- Find The Rest Is Science all over the internet by ⁠⁠clicking here.⁠⁠ ------------------- Video Producer: Adam Thornton + Oli Oakley Video & Social: Bex Tyrrell Assistant Producer: Imee Marriott Producer: Becki Hills Senior Producer: Lauren Armstrong-Carter Head Of Digital: Samuel Oakley Exec Producer: Neil Fearn Learn more about your ad choices. Visit podcastchoices.com/adchoices

Could a bolt of lightning become a permanent geological relic? How small would you have to squash a hamster to turn it into a black hole? Professor Hannah Fry and Michael Stevens dismantle our perceptions of scale and texture, moving from the glassy "fulgurites" forged in sandy soil to the mathematical threshold of the Schwarzschild radius. They explore the counter-intuitive geometry of the Earth, calculate the extreme density required to collapse domestic life into a gravitational singularity and examining the crystalline remains of atmospheric discharge. This is an investigation into the smooth, the sharp, and the impossibly dense, proving that the world we touch is rarely as it seems. ------------------- For more information about Cancer Research UK, their research, breakthroughs and how you can support them, visit ⁠⁠https://cancerresearchuk.org/restisscience⁠⁠ Cancer Research UK is a registered charity in England and Wales (1089464), Scotland (SC041666), the Isle of Man (1103) and Jersey (247). A company limited by guarantee. Registered company in England and Wales (4325234) and the Isle of Man (5713F). Registered address: 2 Redman Place, London, E20 1JQ. ------------------- Find The Rest Is Science all over the internet by ⁠⁠clicking here.⁠⁠ ------------------- Video Producer: Adam Thornton + Oli OakleyVideo & Social: Bex TyrrellAssistant Producer: Imee MarriottProducer: Becki HillsSenior Producer: Lauren Armstrong-CarterHead Of Digital: Samuel OakleyExec Producer: Neil Fearn Learn more about your ad choices. Visit podcastchoices.com/adchoices

What is boredom really, and why does it feel so unbearable? Professor Hannah Fry and Michael Stevens explore the science of boredom, revealing it not as laziness or a lack of stimulation, but as a signal from the brain when prediction and learning grind to a halt. When nothing changes and everything is expected, the mind begins to push back. From dopamine experiments and waiting rooms to sensory deprivation and solitary confinement, they examine how boredom emerges from lost uncertainty and why the brain would rather create discomfort, hallucinations, or anxiety than stop predicting altogether. This episode unpacks the psychology and neuroscience of boredom, showing how surprise drives pleasure, how boredom reshapes behaviour, and why this uneasy emotion may be essential to curiosity, creativity, and human progress. ------------------- For more information about Cancer Research UK, their research, breakthroughs and how you can support them, visit ⁠⁠https://cancerresearchuk.org/restisscience⁠⁠ Cancer Research UK is a registered charity in England and Wales (1089464), Scotland (SC041666), the Isle of Man (1103) and Jersey (247). A company limited by guarantee. Registered company in England and Wales (4325234) and the Isle of Man (5713F). Registered address: 2 Redman Place, London, E20 1JQ. ------------------- Find The Rest Is Science all over the internet by ⁠⁠clicking here.⁠⁠ ------------------- Video Producer: Adam Thornton Video & Social: Bex Tyrrell Assistant Producer: Imee Marriott Producer: Becki Hills Senior Producer: Lauren Armstrong-Carter Head Of Digital: Samuel Oakley Exec Producer: Neil Fearn Learn more about your ad choices. Visit podcastchoices.com/adchoices