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
How Codes Were Used To Hack The Telegram Business
Sep 16, 2026Summary Preview
Michael Stevens and Hannah Fry explore the fascinating intersection of communication technology and physics in this Field Notes episode. They dive into the history of telegrams through an 1900s code book that compressed messages into single words to save money, discuss why we rarely dream about our smartphones despite constant use, explain the physics behind water swirling down drains, and calculate what it would take to survive falling from the world's tallest building.
- The 1900s Telegram Code Book
- The Telegraph's Revolutionary Impact on Society
Why Your Body Needs Gravity
Sep 13, 2026Summary Preview
Hannah Fry and Michael Stevens explore what happened when NASA conducted a real-life twin experiment with astronauts Scott and Mark Kelly. While Einstein's theory predicted time dilation effects from space travel would be minimal at ISS speeds, NASA discovered far more dramatic changes from the physical effects of being in space—from gene expression alterations to surprising telomere lengthening and subsequent collapse. The discussion reveals how fundamentally our bodies are adapted to Earth's gravity and environment, with astronauts essentially sacrificing their health for humanity's advancement.
- Einstein's Twin Paradox and the Kelly Brothers Experiment
- Vision Changes and Fluid Shifts in Space
What Is Collagen All About?
Sep 09, 2026Summary Preview
Michael Stevens and Hannah Fry explore the science behind collagen supplements, examining the marketing claims, manufacturing process, and actual evidence for their effectiveness. Hannah investigates whether these expensive supplements derived from animal byproducts actually deliver on their promises for skin, joints, and overall health, while Michael shares insights about collagen from his barbecuing experience. The episode also features discussion of Ig Nobel Prize winners and listener questions about mathematics and chemistry.
- The Collagen Supplement Industry and Manufacturing
- How Collagen Digestion Actually Works
The Threshold of Human Sensation
Sep 06, 2026Summary Preview
Michael Stevens and Hannah Fry embark on a fascinating journey to answer the question: what's the smallest thing you can feel? They systematically explore human sensory thresholds across taste, smell, hearing, touch, and sight, challenging poetic but unsourced claims found across the internet. Through scientific research and calculations, they progress from emotions requiring trillions of atoms down to the remarkable discovery that humans can detect single photons hitting their eyes, even if not consciously perceived.
- The Challenge of Defining Sensory Thresholds
- Emotions and Hearing: Starting with Trillions
The Scale of the Universe
Sep 02, 2026Summary Preview
In this Field Notes episode of The Rest is Science, Hannah Fry and Michael Stevens explore a stunning visualization that shows how human egg cells sit precisely at the midpoint between the smallest and largest measurable sizes in the universe. They discuss the bizarre lopsidedness of scale, share favorite Wikipedia articles, explain why shower thoughts happen, and correct a previous episode's mistake about historical attitudes toward curiosity.
- The Journey from Planck Length to Observable Universe
- Favorite Wikipedia Articles and Internet Rabbit Holes
Why Loud Chewing Makes You Angry
Aug 30, 2026Summary Preview
Hannah Fry and Michael Stevens explore misophonia - the intense dislike or rage some people experience when hearing certain sounds, particularly eating noises. They discuss the physics of annoying sounds, test theories about why chewing bothers people, examine brain research on mirror neurons, and explore creative solutions to combat the condition, including fascinating experiments with sound-swapped videos.
- The Physics of Universally Horrible Sounds
- Mirror Neurons and the Brain Science of Misophonia
Can Language Change What You Smell?
Aug 26, 2026Summary Preview
Michael Stevens and Hannah Fry explore how language shapes our perception of reality, from Persian smell-detecting abilities to the Sapir-Whorf hypothesis. They then tackle listener questions about escape velocity, soap's ancient origins, and historical scientific misconceptions like the 'rain follows the plow' theory.
- The Persian Smell Mystery and Language Perception
- The Sapir-Whorf Hypothesis: How Language Shapes Reality
Space Elevators, Skyhooks, and Space Fountains
Aug 23, 2026Summary Preview
Hannah Fry and Michael Stevens explore unconventional methods of reaching space, from nuclear explosions to space elevators. They discuss the fastest (a 1957 manhole cover blown off a nuclear test), slowest (waiting billions of years for Earth's eventual journey through space), and most practical future alternatives to expensive rockets, including launch loops and skyhooks that could revolutionize space access.
- The Fastest, Cheapest, and Worst Way to Space
- The Slowest Method: Just Wait
Hannah Ranks Michael's Bizarre Watches
Aug 19, 2026Summary Preview
Hannah Fry and Michael Stevens explore novelty watches from Michael's collection, discuss Bayesian reasoning and probability, examine mathematical learning differences, and answer listener questions about logic and self-efficacy in mathematics.
- Michael's Collection of Novelty Watches
- Bayesian Reasoning and Probability
Summary Preview
This episode explores the science behind GLP-1 (glucagon-like peptide-1) and how it revolutionized diabetes treatment and weight loss medications. Hannah Fry guides Michael Stevens through the fascinating discovery journey—from stomach ulcer surgeries to Gila monster venom—that led to drugs like Ozempic and Wegovy. The discussion covers how the body maintains blood sugar balance, the mechanisms of GLP-1, and how modern pharmaceuticals harness this biology to suppress appetite and regulate metabolism.
- The Body's Delicate Blood Sugar Balance
- The Gut-Pancreas Mystery
Summary Preview
Hannah Fry shares fascinating insights from her recent Arctic expedition, revealing the existence of a massive freshwater lake beneath the North Pole ice sheet called the Beaufort Gyre. This hidden body of water, larger than all the Great Lakes combined, plays a crucial role in protecting Arctic ice and regulating European climate. The episode also explores why people are more likely to correct mistakes online than answer genuine questions, and examines the mathematics and psychology behind coincidences.
- The Arctic's Hidden Freshwater Lake
- The Beaufort Gyre: Climate Guardian and Threat
The Science of Putting Sunglasses on The Sun
Aug 09, 2026Summary Preview
Michael Stevens and Hannah Fry tackle the whimsical yet surprisingly complex challenge of putting sunglasses on the sun. What begins as an absurd thought experiment evolves into a deep exploration of angular diameter, solar viewing safety, and real proposals for space-based solar management. The discussion reveals both the engineering challenges of creating such an illusion and genuine scientific concepts like space sunshades and solar mirrors that could have profound implications for Earth's climate.
- The Initial Challenge: Angular Diameter and Viewing Distance
- The Binocular Vision Problem
Why Is It A Colour Wheel & Not A Line?
Aug 05, 2026Summary Preview
In this Field Notes episode, Michael Stevens shares his latest obsession: organizing a collection of 152 Crayola crayons by color theory. This deep dive into color leads to fascinating discussions about how cameras can't capture fluorescent colors, why purple doesn't exist in the electromagnetic spectrum, and the strange physics behind everyday phenomena like tea leaves clustering in the center of a cup and whether water can be "more wet."
- Michael's Crayon Obsession and the Color Wheel Mystery
- Purple Doesn't Exist: The Color That's All in Your Head
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