The Rest Is Science
Join mathematician Professor Hannah Fry and science creator Michael Stevens (Vsauce) as they dig into the weird scientific questions that often go unexplored. Welcome to The Rest Is Science, a show that sits in the fascinating space between what we think we know, and what we actually know. Why do we assume we understand things like time, randomness, or even gravity? Once you start questioning these familiar ideas, reality becomes astonishingly strange and completely fragile. Whether you're a lifelong science fan or just naturally curious, The Rest Is Science will change your perception of reality, and prove that the biggest questions are always the most fun.
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Recent Episodes
Why Lithium Batteries SUCK
Aug 02, 2026Summary Preview
Michael Stevens and Hannah Fry explore the history and limitations of batteries, from ancient discoveries to modern lithium-ion technology. Hannah argues that lithium batteries are surprisingly inefficient compared to common materials like butter and body fat, and discusses dangerous design flaws while exploring promising future alternatives from sodium batteries to liquid air storage.
- Energy Density: Why Lithium Batteries Are Pathetic
- The Oxford Bell: The Battery That Won't Die
What Happens Inside Earth's Forbidden Zones?
Jul 29, 2026Summary Preview
Hannah and Michael explore exclusion zones around the world where humans cannot go, from the DMZ between North and South Korea to Chernobyl and Fukushima. The discussion reveals how nature flourishes when humans leave, with 38% of Korea's critically endangered species living in the DMZ's narrow 4-kilometer band. They examine how war, nuclear disasters, and toxic pollution have created accidental nature preserves, and consider what this means for humanity's relationship with the natural world. The episode concludes with listener questions about cosmic horror, tectonic plates, and whether they'd rather be the first or last humans.
- The DMZ Gift Shop and Flourishing Wildlife
- Fukushima's Frozen Panic and Radioactive Wildlife
It Wasn't A Hoax After All
Jul 26, 2026Summary Preview
Michael and Hannah explore whether 2012 marked the end of the world as we knew it, not through apocalypse but through a fundamental shift in how humanity connects, consumes media, and organizes society. They examine how 2012 became the tipping point when the Western world transitioned from physical to digital, from shared cultural experiences to fragmented online communities, fundamentally changing human connection and cultural cohesion.
- The 2012 Mayan Calendar Phenomenon
- The 2012 Digital Revolution Tipping Point
Hack Dog Vision To Keep Your Bones Safe
Jul 22, 2026Summary Preview
Michael and Hannah explore the fascinating world of color vision across species, focusing on how different animals perceive colors differently. Michael showcases a clever shirt design that exploits dogs' dichromatic vision, while the conversation expands into discussions about tetrachromats, DNA data storage, free will, and the biological impossibility of fire-breathing dragons.
- The Dog Safety Shirt and Color Vision Variations
- Tetrachromats: Humans Who See Extra Colors
The Hole In Your Brain That Makes You Doomscroll
Jul 19, 2026Summary Preview
This episode of The Rest is Science explores the fascinating nature of human curiosity—from its historical status as a sin to its modern celebration as a virtue. Hosts Hannah Fry and Michael Stevens examine the psychological mechanisms behind curiosity, including the 'information gap' theory, the Pandora effect, and how curiosity can override self-preservation instincts. They discuss how curiosity evolved, its role in learning and memory retention, the dangers of social media exploitation, and why this once-condemned trait is now considered essential to human progress.
- The Psychology of Curiosity and the Pandora Effect
- Curiosity as Sin: 1,500 Years of Condemnation
A Man-Eating Tiger Found In London
Jul 15, 2026Summary Preview
Michael and Hannah explore the fascinating history of man-eating tigers in India, discussing DNA forensics used to identify killer tigers, conservation efforts, and the ethical dilemmas of dealing with dangerous wildlife. They also tackle listener questions about pleasure responses, mathematical ratios in nature, and what makes a good question.
- The Taxidermied Tiger Discovery
- The Champawat Tiger: History's Deadliest Man-Eater
All The People You Don't Know
Jul 12, 2026Summary Preview
Hannah Fry and Michael Stevens explore the science of friendships and social connections, from familiar strangers to the friendship paradox. They discuss surprising research showing that most friendships aren't reciprocal, your friends have more friends than you do (mathematically), and that diverse social networks - including weak ties and strangers - significantly improve physical health and mental wellbeing. The conversation reveals how our perception of social connections is often warped by network effects and sampling bias.
- The Reciprocity of Friendship
- Types of Strangers: From Familiar to Intimate
An Honest Dad Ranking
Jul 08, 2026Summary Preview
Michael Stevens joins from New Zealand, sharing a humorous Father's Day gift - a coffee mug ranking him as the 1,093,750,012th dad based on his 6-year-old daughter's assessment. The episode explores the mathematics behind parental rankings, discusses whether fans can propel sailboats, examines the future of solar eclipses over Manhattan, and investigates why darkness on stairs triggers primal fears.
- The Honest Dad Ranking
- Mathematical Paradoxes in Parent Statistics
Your Brain Invents Pain. Here's Why.
Jul 05, 2026Summary Preview
Hannah Fry and Michael Stevens explore the science of pain, from testing their own pain thresholds in ice water to examining people who feel no pain at all. They discuss how pain is constructed by the brain rather than being a direct readout of tissue damage, the mechanisms behind pain perception, and promising research into new pain treatments that could target specific neural pathways without the side effects of opioids.
- Testing Pain Thresholds with Ice Water
- The Thermal Grill Illusion: Tricking the Brain into Feeling Pain
The Most Dangerous Rock In Hannah's Collection
Jul 01, 2026Summary Preview
Hannah Fry and Michael Stevens explore listener questions about gravitational waves, space debris, and stair-climbing physics before diving deep into obsidian—the sharpest naturally occurring material on Earth. They discuss its volcanic origins, historical significance as humanity's oldest trade good, and remarkable properties that make it sharper than surgical steel.
- Gravitational Waves and Human Perception
- Space Junk: The Growing Orbital Debris Crisis
Summary Preview
Michael Stevens and Hannah Fry explore the fascinating world of auditory and visual illusions, questioning whether these phenomena are truly 'illusions' or simply how our brains have evolved to process information efficiently. They examine how perception varies based on lived experience, from pitch perception to famous viral illusions like Yanni/Laurel and the dress, ultimately arguing that our subjective experience of reality may be more important than objective truth for survival.
- The Nature of Pitch: Percussion at High Speed
- The Hard Problem of Consciousness and Qualia
Will A 25 Year Old Space Pen Still Write?
Jun 24, 2026Summary Preview
In this Field Notes episode, Michael Stevens brings a cherished space pen from his childhood space camp days to finally test after 25 years. The hosts explore the history and science of Fisher space pens used by NASA astronauts, conduct their long-awaited experiment, and answer listener questions about astronaut orientation in space, the destructive potential of synchronized clapping, and the Kardashev scale for measuring civilizations' energy usage. The episode balances nostalgic experimentation with thoughtful skepticism about popular science concepts.
- The Space Pen Experiment: 25 Years in the Making
- Space Camp Memories and Weightless Training
A Paleontology Of The Future
Jun 21, 2026Summary Preview
Michael Stevens and Hannah Fry explore the fascinating world of archaeology beyond Earth, from the historical artifacts left at Tranquility Base on the moon to ancient manuports that reveal the earliest signs of abstract human thought. The discussion spans space law, territorial ownership, the deepest hole ever drilled on Earth, and how preservation of human sites both on Earth and in space creates a legacy for future civilizations.
- Tranquility Base and Space Archaeology
- Artifacts, Ecofacts, Geofacts, and Manuports
What Are The Odds You'll Become A Fossil?
Jun 17, 2026Summary Preview
Hannah Fry and Michael Stevens explore fossils, paleontology, and human history in this Field Notes episode. Hannah presents a fossilized bone she believes to be from an Ice Age reindeer found in France, discussing the extreme rarity of fossilization and how prehistoric human settlements may have contributed to this particular fossil's creation. The hosts then tackle listener questions about what would happen if the sun vanished, the evolutionary origins of gossip, and why we shouldn't throw nuclear waste into volcanoes.
- Hannah's Fossilized Reindeer Bone
- The Process of Fossilization
Why Are Our Feet So Wierd?
Jun 14, 2026Summary Preview
Hannah Fry and Michael Stevens explore the fascinating biomechanics of human feet, revealing how decades of scientific understanding were overturned by recent research. The episode covers everything from evolutionary advantages of our unique foot structure to the surprising prevalence of foot fetishes, mixing serious science with entertaining personal anecdotes about Michael's famously hairy feet.
- The Peculiarity of Human Feet
- The Mechanics of Walking: Why Flat Feet Don't Work
How Many Words Do You ACTUALLY Know?
Jun 10, 2026Summary Preview
Hannah Fry and Michael Stevens explore vocabulary testing through VocabOwl, a website created by listener Jake that estimates how many words you know. They compare their results, discuss fascinating obscure words, and dive into questions about internal monologues, talking to oneself, and the quirks of human cognition. The episode reveals surprising personal insights about how each host processes thoughts differently.
- VocabOwl: Testing Your Vocabulary
- Vocabulary Mistakes and Obscure Words
The Creepy Reason Police Want Your Face
Jun 07, 2026Summary Preview
Hannah Fry and Michael Stevens explore the fascinating intersection of neuroscience, privacy, and law, examining whether thoughts should be protected like physical evidence and how emerging brain-scanning technology challenges our understanding of the Fifth Amendment. They delve into cases where biometric phone unlocking, P300 brain scans, and mind-reading technology raise fundamental questions about mental privacy, criminal justice, and what it means to own your own thoughts.
- The Phone Unlock Paradox: Face ID vs. Passcode
- Fifth Amendment Origins: From Trial by Ordeal to Mental Privacy
Nikola Tesla Fell In Love with a Pigeon
Jun 03, 2026Summary Preview
Michael Stevens and Hannah Fry explore a Tesla coil given to Michael by comedian Romesh Ranganathan, discussing the physics of electricity, the fascinating life of Nikola Tesla, and answering listener questions about ancient symbols, hypnosis, and the philosophical nature of nothingness. The episode combines hands-on science demonstration with deep dives into electrical engineering history and cognitive science.
- Tesla Coil Demonstration and Basic Physics
- Nikola Tesla's Life and Wild Ambitions
Michael Discovered A New Way To Make Twins
May 31, 2026Summary Preview
Michael Stevens and Hannah Fry explore the fascinating science of genetics, twins, and cell ownership through the lens of probability, ethics, and law. They discuss how identical twins could theoretically occur through random chance, delve into the landmark case of Henrietta Lacks whose immortal cells revolutionized medicine without her knowledge, and examine the complex legal landscape surrounding genetic material ownership, cloning, and the right to publicity.
- The Mathematics of Twins: A Third Way to Create Genetic Duplicates
- The Immortal Cells of Henrietta Lacks
Why Michael Abandoned Ink
May 27, 2026Summary Preview
Michael Stevens shares his extensive journey from being a pen devotee to becoming a mechanical pencil enthusiast, exploring the technical details, features, and personal preferences that make the perfect writing instrument. The discussion covers lead hardness, pencil mechanisms, and the philosophy behind choosing writing tools, with Hannah Fry providing commentary and sharing her own fountain pen preferences.
- The Conversion from Pens to Pencils
- The Philosophy of Writing by Hand