// Scientific Brain Teasers
Science Puzzles
The prize is in the pleasure of finding things out
300
Puzzles
6
Fields
3
Levels
One question, one answer, one idea worth thinking about. Reason it out, reveal the answer, then watch the remastered episodes that explore the science behind it.
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Atmospheric X-Ray
Balance in a Vacuum
Black Hole Information
Boltzmann Brains
Burning Crab Lines
Can a swamp clean dirty water?
Can Sound Turn a Corner but Light Cannot?
Can You Crack Nature’s Pattern?
Can You Ever Reach the End of a Rainbow?
Can You Mix It Back?
Can You Pull a Rope Perfectly Straight?
Can You Read the Volcano’s Warning Signs?
Can You Spot the Bad Experiment?
Cantilever Tension
Combustion Dependency
Could a Blue Whale Survive on Land?
Could You Hear an Explosion in Space?
Could You Jump Over a House on the Moon?
Genetic Thread Count
Hot Tea, Cold Milk: When Should You Add the Milk?
How Are Limestone Caves Made?
How Can a Cow Live on Grass?
How Can a Gecko Walk Upside Down on Glass?
How Can a Lighthouse Be Seen So Far Away?
How Can a Paperclip Float?
How Can a Rock Float?
How Can an Animal Survive the Vacuum of Space?
How Can Ice Fall from the Sky in Summer?
How Can Light Travel Round Corners in a Glass Fibre?
How Can One Hand Lift a Car?
How Can Solid Ground Turn to Liquid?
How Can We Spot a Planet Round Another Star?
How Cold Can Anything Get?
How Deep Is the Deepest Hole Ever Dug?
How Did Eratosthenes Measure the Earth?
How Did Seashells Get to the Top of Everest?
How Did Two Teams Dig a Tunnel and Meet in the Middle?
How Do Astronauts Weigh Themselves in Space?
How Do Diamonds Reach the Surface?
How Do We Know Earth’s Outer Core Is Liquid?
How Do We Know the Continents Move?
How Do We Know What Stars Are Made Of?
How Do We Know What the Air Was Like a Million Years Ago?
How Does a Bee Tell the Hive Where the Flowers Are?
How Does a Bike Dynamo Make Electricity?
How Does a Bone Turn into Stone?
How Does a Canal Lock Lift a Boat?
How Does a Chameleon Change Colour?
How Does a Flask Keep Tea Hot?
How Does a Flower Trick a Bee?
How Does a Fridge Make Things Cold?
How Does a Kettle Know When to Switch Off?
How Does a Lightning Rod Protect a Building?
How Does a Plane Stay Up?
How Does a Seed Know Which Way Is Up?
How Does a Siphon Make Water Flow Uphill?
How Does a Smoke Alarm Smell Smoke?
How Does a Toilet Cistern Know When to Stop Filling?
How Does a Train Turn a Corner?
How Does a Venus Flytrap Know It’s Caught a Fly?
How Does Water Reach the Top of the Tallest Tree?
How Does Your Phone Know Where You Are?
How Far Away Is the Storm?
How Fast Are You Moving Right Now?
How Long Is the DNA in One of Your Cells?
How Long Would a Year Be Twice as Far from the Sun?
How Long Would It Take to Count Your Cells?
How Long Would It Take to Drive to the Moon?
How Many Ancestors Do You Have?
How Many Earths Would Fit Inside the Sun?
How Many of the Pea Plants Will Be Short?
How Much Further Does a Faster Car Need to Stop?
How Much Hair Do You Grow in a Day?
How Much More Power Is in Twice the Wind?
How Old Is the Light from Andromeda?
How Old Is the Water in Your Glass?
How Old Is This Rock?
Ice Cream Causes Sunburn: True or False?
Ice in a Full Glass: Will It Overflow?
If the Sun Vanished, When Would We Know?
Is the Blood in Your Veins Blue?
Is the Metal Colder Than the Wood?
Lunar Pendulum Clock
Mass of the Pendulum
Maxwell’s Demon
Melting Iceberg Stasis
My Grandfather Smoked
Ocean Salinity Origin
Olbers’ Dark Sky
One Result Is Not a Result
Orbital Trajectory
Peto’s Paradox
Pirogue Displacement
Sharp Shooting the Barn Door
Solar Eclipse Geometry
Solid, Liquid or Both?
Sound of a Space Spark
The 68,000,003-Year-Old Dinosaur
The Absence in the Telescope
The Anomaly in the Data
The Armour Dilemma
The Bartender’s Pistol
The Base Rate Fallacy
The Bernoulli Constriction
The Billionaire in the Café
The Birthday Surprise
The Charcoal Lifecycle
The Climbing Accountant
The Coastline Paradox
The Cosmic Balloon
The Cure That Only Works on Mice
The Dartboard and the Clock
The Desert Pack
The Doubloon Ratio
The Dowser’s Challenge
The Drawer of Failed Studies
The Drug That Halves Your Risk
The Echo Reflection
The Elevator Tool
The Fermi Silence
The Fertiliser That Proved Nothing
The Four T-Posts
The Graph That Starts at Ninety
The Gravity Slingshot
The Gulp Bait Selection
The Gyroscopic Wheel
The Happiest Plants in the Lab
The Keys Under the Streetlight
The Lazy Balloon
The Lucky Socks
The Missing Half of the Trial
The Money Bag That Grew Too Much
The Mpemba Effect
The Neutrinos That Beat Light
The Poll of Two Million People
The Professor Said So
The Puppy That Would Outgrow the House
The Rat Tail Bounty
The Relativistic Twins
The Sliding Pucks
The Ten-Pence Blind Spot
The Theory That Explains Everything
The Three Doors
The Treatment That Wins and Loses
The Two Maternity Wards
The Umbrella Blame
The Unseen Weight
The Wason Sequence
The Worst Schools Improve
Twenty Jellybean Colours
Two Explanations, One Comet
Two-Pan Boudin Balance
Wetland Filtration
What Carved This Canyon?
What Comes Next in the Method?
What Does a Rocket Push Against in Space?
What Does the Fingerprint Tell You?
What Is a Shooting Star?
What Makes the Northern Lights Glow?
What Makes You Gasp for Breath?
What Shape Is a Candle Flame in Space?
What’s Hiding in a Drop of Pond Water?
When Is Earth Closest to the Sun?
Where Did the Energy Go?
Where Did the Moon Come From?
Where Do Autumn Leaves Get Their Colour?
Where Do the Stars Go in the Daytime?
Where Does a Hurricane Get Its Energy?
Where Does a Tree’s Mass Come From?
Where Does Fat Go When You Lose Weight?
Where Does White Sand Come From?
Which Animal Doesn’t Belong?
Which Bulb Burns Brighter?
Which Came First in the Rock?
Which Cloud Brings the Rain?
Which Comes First, the Tadpole or the Frog?
Which Cools Faster, the Big Mug or the Small Cup?
Which Dam Needs to Be Stronger?
Which Gear Gets You Up the Hill?
Which Hits the Ground First?
Which Is the Biggest Desert on Earth?
Which Magnet Wins the Tug of War?
Which Measurement Can You Trust?
Which Mountain Top Is Furthest from Earth’s Centre?
Which Rolls Down the Ramp First?
Which Shape Holds the Most Weight?
Which Spanner Loosens the Stuck Nut?
Which Star Is the Hottest?
Which Way Does a Comet’s Tail Point?
Which Way Does a Compass Really Point?
Which Way Does the Balloon Lean When the Car Brakes?
Which Way Does the Blood Go?
Which Way Does the Storm Spin?
Which Way Is Down in Space?
Which Way Up Is a Plank Stiffer?
Who Knew What in the Trial?
Why Are Aeroplane Windows Round?
Why Are Astronauts’ Visors Coated in Gold?
Why Are Bricks Laid in an Overlapping Pattern?
Why Are Cars Built to Crumple?
Why Are Cities Warmer Than the Countryside?
Why Are Flamingos Pink?
Why Are Manhole Covers Round?
Why Are More Men Colour-Blind Than Women?
Why Are Planets Round but Asteroids Lumpy?
Why Are Racetrack Bends Tilted?
Why Are the Hawaiian Islands in a Line?
Why Are There No Green Mammals?
Why Are There Two High Tides a Day?
Why Are Tunnel Lights Brightest at the Entrance?
Why Can You Hear a Train Through the Rails First?
Why Can You Only See the Space Station at Dawn and Dusk?
Why Can’t You See Colours in the Dark?
Why Can’t You Tickle Yourself?
Why Did the Ozone Hole Open Over Antarctica?
Why Did the Tortoises Grow So Big?
Why Do Airliners Fly So High?
Why Do Antibiotics Stop Working?
Why Do Astronauts Grow Taller in Space?
Why Do Bees Build Hexagons?
Why Do Bridges Have Gaps in the Road?
Why Do Cacti Breathe at Night?
Why Do Cathedrals Have Flying Buttresses?
Why Do Cats’ Eyes Shine in the Dark?
Why Do Chillies Burn but Birds Don’t Mind?
Why Do Drink Cans Have Domed Bottoms?
Why Do Earthquakes Happen Where They Do?
Why Do Geese Fly in a V?
Why Do Geysers Erupt on a Timetable?
Why Do Golf Balls Have Dimples?
Why Do Onions Make You Cry?
Why Do Power Lines Carry Such High Voltage?
Why Do Snowflakes Have Six Sides?
Why Do Some Volcanoes Explode While Others Ooze?
Why Do Stars Twinkle but Planets Don’t?
Why Do Tractors Have Such Wide Tyres?
Why Do We Always See the Same Side of the Moon?
Why Do We Get Goosebumps?
Why Do We Put Salt on Icy Roads?
Why Do You Get a Fever?
Why Do You Need Two Eyes?
Why Do You Only Catch Chickenpox Once?
Why Do Your Ears Pop on a Plane?
Why Do Your Eyes Fall for This Trick?
Why Does a Car Window Shatter into Little Cubes?
Why Does a Cold Can Sweat?
Why Does a Cut Stop Bleeding?
Why Does a Glow Stick Fade Faster in Hot Water?
Why Does a Lake Freeze from the Top Down?
Why Does a Lift Have a Counterweight?
Why Does a Mirror Swap Left and Right?
Why Does a Plant Lean Towards the Window?
Why Does a Red-Hot Nail Fall Off a Magnet?
Why Does a Rubbed Balloon Stick to the Wall?
Why Does a Siren Change Pitch as It Passes?
Why Does a Wet T-Shirt Look Darker?
Why Does Food Get Hot in a Microwave but the Plate Doesn’t?
Why Does Helium Make Your Voice Squeaky?
Why Does Popcorn Pop?
Why Does Saturn Have Rings?
Why Does Sweating Cool You Down?
Why Does the Moon Change Shape?
Why Does the Moon Look Bigger Near the Horizon?
Why Does the Moon Turn Red in an Eclipse?
Why Does the Sea Breeze Turn Around at Night?
Why Does the Spinning Skater Speed Up?
Why Does the Straw Look Bent?
Why Does Warm Lemonade Go Flat Faster?
Why Does Water Boil Below 100 Degrees on Everest?
Why Doesn’t a Bird on a Power Line Get a Shock?
Why Doesn’t the Bridge Fall Down?
Why Doesn’t the Leaning Tower Fall Over?
Why Doesn’t the Sun Burn Out Like a Fire?
Why Doesn’t the Water Fall Out?
Why Doesn’t Your Stomach Digest Itself?
Why Don’t Antarctic Fish Freeze?
Why Don’t Clouds Fall Out of the Sky?
Why Don’t Penguins’ Feet Freeze?
Why Don’t Rivers Flow in Straight Lines?
Why Don’t Ships Notice a Tsunami?
Why Is a Day on Venus Longer Than Its Year?
Why Is an Egg So Hard to Crush?
Why Is Glacier Ice Blue?
Why Is Iceland Getting Wider?
Why Is Io Covered in Volcanoes?
Why Is It Colder on Top of a Mountain?
Why Is Mars Red?
Why Is One Side of the Mountain So Dry?
Why Is the Air on Mars So Thin?
Why Is the Desert Freezing at Night?
Why Is the Moon Covered in Craters but Earth Isn’t?
Why Is the Sea Floor Striped Like a Barcode?
Why Is the Sea Salty but the Rain Is Not?
Why Is the Sky Blue but the Sunset Red?
Why Is There a Giant Ball Inside Taipei 101?
Why Is Venus Hotter Than Mercury?
Why Isn’t Pluto a Planet Any More?
Why Was 2000 a Leap Year but 1900 Wasn’t?
Why Won’t Your Phone Work with Gloves On?
Zeno’s Motionless Arrow
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