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let me guess What happens when a spinning skater pulls her arms in? spinmotionphysicsskating Discover

let me guess Where does the Sun's gravity finally run out as you travel farther away? gravityspacesundistance Discover

show me When the same heavy block stands on a big flat foot or a tiny pointy foot, which one stays on top of the squishy mud? pressurepush and pull Discover

show me A plant gets all its water. Does it still need the sun? plantssunlightgrowing Discover

show me When your arm's muscle lets go, what does the arm do? musclesbodypush and pull Discover

show me Why does some ice come out white and cloudy, and some come out clear? icefreezingair Discover

show me When the sun comes up, where does the morning fog go? weatherfogwater Discover

show me A truck sprinkles salt on the icy road — but what does the salt do? icemeltingwinter Discover

show me Glue is soft and gooey now — so why does it turn rock hard later? gluedryingstates of matter Discover

show me What happens to a jar of big and little balls when you shake it? mixingsizes Discover

show me A pot bubbles and bubbles — and the water keeps getting smaller. Where does it go? watersteamstates of matter Discover

show me When your hand is greasy, can plain water rinse it clean by itself? soapwaterwashing Discover

show me Why is a shadow's edge sometimes crisp and sometimes all soft and blurry? lightshadows Discover

show me Can water always drink up our spoons of sugar? dissolvingwatersugar Discover

show me When you stop spinning, does the inside of you stop too? earsbalancedizzy Discover

show me Why do tightrope walkers carry a big long pole? balancepushes and pulls Discover

show me Why does a volcano sometimes pour out slow and calm, and sometimes go BANG? volcanoesgasearth Discover

show me You blow a bubble from clear, see-through soapy water — so what is hiding inside its skin? lightcolorbubbles Discover

show me A laser and a flashlight both shine far away — what happens to their light? lightlasers Discover

show me What happens to the big balloon when we light a warm flame under it? floatingwarm and coolballoons Discover

show me When you walk into a dark room, when can you see? eyessensesdark Discover

show me Why does a wet hand feel cold? wet and drywarm and cold Discover

show me When the microwave dings, what comes out hot? microwavewaterheat Discover

show me Can you tickle your own foot? brainsensestickle Discover

show me A storm flashes and booms — which one gets to you first? weatherlightsound Discover

show me When you pull a string tight, does its song go high or low? soundmusicpitch Discover

show me If you give a little block and a big block the very same push, who zooms away? motionpush and pullheavy and light Discover

show me One feels icy, one feels cozy — are they the same temperature, or different? heatmaterialstouch Discover

show me When you drop ice in water, will it float or sink? watericefloating Discover

show me Same metal — a tight ball and a wide boat. Which one floats? floatingboatswater Discover

show me What happens when you pour sour lemon on a pile of white baking powder? acidsfizzkitchen Discover

show me We scrunch one sheet into a ball, leave the other flat, and drop both — who lands first? airgravityfalling Discover

show me Why do caves echo when you shout into them? soundechoes Discover

show me What happens to a red apple when only green light shines on it? lightcolor Discover

show me When a wall drops between your gadgets and a toy across the room — who still gets through? signalswaveswireless Discover

show me When you spin a top fast, will it fall down or stay up? spinbalancemotion Discover

show me What happens when you blow really hard between two hanging cans? airpush and pull Discover

show me When you swing a bucket of water up over your head, what does the water do? motionswingingwater Discover

show me What sends a swing way up high — pushing a lot, or pushing at the right time? swingsrhythm Discover

show me What happens when you pile every color onto one spot? colorlightmixing Discover

show me Why does a siren's song change as it zooms past you? soundhigh and low Discover

show me Why is the sky blue (and what happens to it at bedtime)? lightcolorsky Discover

show me What wakes up a sleepy screen when you touch it? electricitysensestech Discover

show me Drop a heavy rock and a floaty feather — who lands first? gravityfalling Discover

show me We put the same sugar in a warm cup and a cool cup — which one makes it vanish first? dissolvingwarm and cool Discover

show me What keeps a little candle flame alive? fireair Discover

let me guess Where does sand come from? rockserosionbeachesearth Discover

let me guess Why do ocean waves only crash and break when they reach the shore? wavesoceanwaterbeach Discover

let me guess The Moon keeps one face toward us — so is it spinning, or frozen still? moonorbitspace Discover

let me guess Stare hard at a colored shape, then look away — what shows up? eyescolorvision Discover

let me guess There's a hole in your vision you've never noticed — where is it? eyesvisionbrainbody Discover

let me guess What happens to a birthday candle's smoke right after you blow it out? firecandlesfuelchemistry Discover

let me guess What happens when you punch a tub of cornstarch-and-water — and when you press it slowly? materialsnon-newtonianstates of matterspeed Discover

let me guess What happens to pepper floating on water when you touch it with a soapy finger? surface tensionwatersoap Discover

let me guess What happens when you mix two cool liquids together — does the mix stay cool? chemistryreactionsheatenergy Discover

let me guess What happens to the fizz tablet when you drop it in cold water versus warm water? chemistryreactionstemperaturesurface area Discover

let me guess What happens when you pour syrup, water, and oil into one glass? densityliquidsfloating Discover

let me guess How long is a coastline — and would two people ever measure the same number? fractalsmeasurementmapsmath Discover

let me guess In tic-tac-toe, does the player who goes first have a secret edge? gamesstrategyfairnesslogic Discover

let me guess Can a message fix itself if some of it gets scrambled on the way? informationerror correctioncodespatterns Discover

let me guess What's the fastest way to find one name in a giant sorted list? searchingalgorithmscomputers Discover

let me guess How does a phone shrink a huge photo small enough to send in a flash? compressionfilescomputerspixels Discover

let me guess Up close, what is a screen picture made of? screenscolorlighttechnology Discover

show me Why does a cut apple turn brown on the table? airfoodcolor Discover

show me How does a heavy metal ship float on water? floatingboatswater Discover

let me guess How do you split a cake so nobody feels cheated? fairnessstrategysharing Discover

let me guess Why does adding a brand-new road sometimes make EVERYONE'S drive slower? networkssystemstraffic Discover

let me guess Can you tell if a long string of numbers is real randomness or a person faking it? randomnesspatternsprobability Discover

let me guess Why does one person staying home from a party tip it from packed to empty? systemsfeedbacksocial Discover

let me guess If everyone throws their hat in a pile and grabs one at random, will someone still get their own? probabilitycountingpatterns Discover

let me guess Two friends build a secret number over a line a spy is listening to — how can they end up sharing a number the spy can't make? encryptionsecretslogic Discover

let me guess Why do gossip, viral videos, and rumors blow up fast at first, then suddenly stall? networksfeedbackspread Discover

let me guess If you guess on a 3-door game show, should you switch doors after a hint? probabilitylogicgames Discover

let me guess Can you really fit ALL the counting numbers into the spaces between 0 and 1? infinitycountinglogic Discover

let me guess Is a snowflake's left side really a perfect mirror of its right — and what if you break the mold? symmetrypatternsshapes Discover

let me guess Why does cutting one wire sometimes take down the whole internet, and sometimes nothing at all? networkssystemsresilience Discover

let me guess In a room of 30 kids, what are the odds two of them share a birthday? probabilitypatternscounting Discover

let me guess Why does a sandpile, dropped one grain at a time, suddenly avalanche — and you can't say which grain did it? systemsfeedbackpatterns Discover

let me guess Why does a tiny rule, repeated over and over, make a giant detailed pattern? patternsfractalsinfinity Discover

let me guess Why do fireflies (and clapping crowds) end up blinking all together with no leader? networksfeedbackpatterns Discover

let me guess Why can a thermostat (or a body) hold steady, but a microphone near its speaker screams? feedbacksystemscontrol Discover

let me guess Why does one line at the bank beat a separate line for each teller? queuesaveragessystems Discover

let me guess What makes a swing go higher — a big push, or the right timing? rhythmpatternsfeedback Discover

let me guess Why can you hold your breath longer after taking fast deep breaths first? breathingbodyoxygen Discover

let me guess Why does cold water feel colder than cold air at the same temperature? skinsensesheatbody Discover

let me guess Deadly vs fast-spreading — which germ takes over a town? germscontagionevolution Discover

let me guess Why does washing your hands stop the spread but a sneeze doesn't? germscontagionhealth Discover

let me guess Why do moths near cities turn dark? evolutionanimalssurvival Discover

let me guess Where does a giant tree's wood actually come from? plantsphotosynthesisair Discover

let me guess Is sunlight or water keeping this plant alive? plantsphotosynthesisenergy Discover

let me guess Why does a wound get red and puffy when it's healing? immune systemhealingbody Discover

let me guess Why does your body remember a germ it already beat? immune systemgermshealth Discover

let me guess Why does sugar give you energy but you can't eat just sugar? foodenergybody Discover

let me guess Why do your eyes take a minute to see in the dark? eyessenseslight Discover

let me guess Why does your arm only pull, never push? musclesbodymovement Discover

let me guess Why don't your bones snap when you jump? bonesbodystructure Discover

let me guess What decides whether a cut heals clean or leaves a scar? skinhealingbody Discover

let me guess Why does poking your skin sometimes hurt and sometimes just ache a beat later? neuronssensesbody Discover

let me guess How does your ear tell a high note from a low note? earssoundsenses Discover

let me guess Why does dropping air pressure tell you a storm is coming? weatherpressurestormsair Discover

let me guess Why does the wind make giant waves out at sea but not in a pond? oceanswaveswindwater Discover

let me guess Why is it pitch dark at night when space is full of stars? spacestarslightuniverse Discover

let me guess Why do hailstones grow big in summer, the hottest time of year? weatherhailcloudswind Discover

let me guess Why does the wind near the coast switch direction between day and night? weatherwindoceanstemperature Discover

let me guess Why do astronauts float if there's still gravity up there? spacegravityorbitsastronauts Discover

let me guess Why does fog appear in the morning and then vanish? weatherfogtemperaturewater Discover

let me guess Why does a planet's year get longer the farther out it is? spaceorbitsgravityplanets Discover

let me guess Why does the ocean stay salty but rain is fresh? oceanswatersaltweather Discover

let me guess Why does a hurricane spin in a circle? weatherhurricaneswindearth Discover

let me guess Why does it get colder the higher up a mountain you go? weathertemperatureairpressure Discover

let me guess Why doesn't the Moon just fall down onto us? spaceorbitsgravitymoon Discover

let me guess Why does the day stay light longer in summer? earthseasonsday lengthsunlight Discover

let me guess Why does a volcano explode instead of just oozing? earthvolcanoespressuregas Discover

let me guess Why isn't there an eclipse every single month? spaceeclipsesmoonorbits Discover

let me guess Why does the Moon change shape every night? spacemoonlightorbits Discover

let me guess Why does a wet sandcastle hold its shape but dry sand just slides flat? materialswaterstates of matter Discover

let me guess Why does hand sanitizer feel freezing cold but water doesn't? evaporationheatstates of matter Discover

let me guess Why does a cup of mixed colored sand un-mix when you shake it? mixingmaterialssize Discover

let me guess Why does salt melt the ice on a sidewalk but sugar barely helps? dissolvingfreezingstates of matter Discover

let me guess Why does a balloon stretch huge but a clay ball just splats? materialselasticitymolecules Discover

let me guess Why does freezer ice turn out cloudy but fancy ice is crystal clear? freezingcrystalsstates of matter Discover

let me guess Why does a cut apple turn brown — and can you stop it? oxygenreactionsrust Discover

let me guess Why does steam puff out of a pot but you can't see it right at the spout? states of matterevaporationwater Discover

let me guess Why does a steel ship float when a steel marble sinks? densityfloatingshapes Discover

let me guess Why does red cabbage juice turn pink in lemon and green in soap? acidsbasesindicators Discover

let me guess Why does white glue dry hard but stay gooey in the bottle? gluedryingstates of matter Discover

let me guess Why does oil and vinegar split apart no matter how hard you shake them? mixingoilwater Discover

let me guess Why do salt crystals come out as little cubes but never as wobbly blobs? crystalsshapesdissolving Discover

let me guess Why does a candle flame die under a glass but burn forever in the open? fireoxygencombustion Discover

let me guess Why does soap wash off greasy hands but water alone just rolls off the grease? soapwatermolecules Discover

let me guess Why does lemon juice fizz on baking soda but water just sits there? acidsbasesreactions Discover

let me guess Why does an iron nail turn orange and crumbly but a gold ring never does? rustmetalsoxygen Discover

let me guess Why does sugar vanish in water but sand just sits there? dissolvingwaterstates of matter Discover

let me guess Why does shaking a rope fast make tiny ripples but shaking it slow makes big rolls? wavesphysicssound Discover

let me guess Why does the moon look huge near the horizon but tiny up high? lightperceptionoptics Discover

let me guess Why does a sound die out fast in a small room but echo forever in a cave? soundechoesreflection Discover

let me guess Why does a red apple turn black under a green light? colorlightperception Discover

let me guess Why does plucking a tighter guitar string make a higher note? soundmusicpitch Discover

let me guess Why does a thin soap bubble swirl with rainbow colors when soapy water is clear? lightcolorinterference Discover

let me guess What happens when two identical sounds overlap? soundwavesinterference Discover

let me guess Why does a magnifying glass flip the world upside down when you back it away? lightlensesoptics Discover

let me guess Why is a laser pointer a tiny dot far away but a flashlight is just a blob? lightlaserswaves Discover

let me guess Why do bendy glass threads carry far more of your video call across the world without it fading? lightfiberreflection Discover

let me guess Why does a police siren change its note as it races past you? soundwavesdoppler Discover

let me guess Why does a pencil's shadow have a fuzzy edge sometimes and a sharp edge other times? lightshadowsoptics Discover

let me guess Why does a rainbow always curve, and could you ever reach its end? lightcolorrainbows Discover

let me guess Why does a roller coaster need a big first hill to make it all the way around? motiongravityenergy Discover

let me guess Why does a wide tractor tire roll over mud that a skinny bike tire sinks into? pressureforcesurfaces Discover

let me guess Two sheets of the same paper, same weight — do they fall at the same speed? airgravitymotion Discover

let me guess Why is it easier to lift a heavy bucket from a well with a wheel on top? machinesforcesimple-machines Discover

let me guess Why does a parachute let you fall slowly when a rock just drops? airgravitymotion Discover

let me guess Why are two eyes better than one? eyessensesdepth Discover

let me guess Why does some thunder crack but other thunder rumbles? soundwavesphysics Discover

let me guess Why doesn't the water spill when you swing a bucket over your head? motionforcegravity Discover

let me guess What does spinning do to a top that's about to fall over? balancemotionspin Discover

let me guess Can you mix two photos so a stranger can't read them, but your friend can? encryptionsecretslogic Discover

let me guess How does a computer remember things even after you turn it off? memorycomputerselectricity Discover

let me guess Two gears, one big and one small — which spins faster, and can gears ever give you free speed? gearsratiosmachines Discover

let me guess If most buses run half-empty, what kind of bus does a random rider land on? averagesprobabilityeveryday Discover

let me guess Is a coin that just landed heads five times 'due' for tails? probabilityrandomnessluck Discover

let me guess If everyone is driving fine and nobody crashes, how does a traffic jam appear out of nowhere? trafficfeedbacksystems Discover

let me guess Why do you get dizzy after spinning? earsbalancebrain Discover

let me guess Does your own hand tickle you as much as a friend's? brainsensesneurons Discover

let me guess Why does your heart beat in two thumps? heartbloodbody Discover

let me guess Why do you breathe faster when you run? breathingbodyoxygen Discover

let me guess Why does the sea have a high tide and a low tide every day? oceanstidesmoongravity Discover

let me guess Why do you see lightning way before you hear the thunder? weatherthunderlightsound Discover

let me guess Why does wind blow from one place to another? weatherwindairpressure Discover

let me guess Why does it rain instead of just staying cloudy forever? weatherraincloudstemperature Discover

let me guess Why do clouds float if they are full of water? weathercloudswaterair Discover

let me guess Why does a metal spoon feel colder than a wooden one sitting right next to it? heatmaterialsconduction Discover

let me guess Can you keep stirring sugar into water forever? dissolvingsaturationlimits Discover

let me guess Why does hot cocoa mix in fast but cold milk leaves clumps? dissolvingheatspeed Discover

let me guess If you dissolve a whole sugar cube in water, does the water weigh more? dissolvingmassconservation Discover

let me guess Why can a singer shatter a glass with just the right note? soundresonancepitch Discover

let me guess Why does mixing all the paint colors make brown, but all the lights make white? colorlightmixing Discover

let me guess Why can't you see around a corner, but you can hear around one? soundwavesdiffraction Discover

let me guess Why does a spoon look bent when you put it in water? lightrefractionlenses Discover

let me guess A magnet can make a coil of wire light a bulb — but what's the secret to making it glow? magnetselectricitymotion Discover

let me guess Why does rubbing a balloon on your hair make it stick to the wall? electricityforcecharge Discover

let me guess Why do holiday lights all go dark when one bulb dies, but house lights don't? electricitycircuitsphysics Discover

let me guess Why does a bulb only light up when the wire makes a full loop? electricitycircuitsforce Discover

let me guess What does heating do to the air in a hot-air balloon? floatingpressureheat Discover

let me guess What happens when you blow as hard as you can between two hanging soda cans? pressureairforce Discover

let me guess Why does a bike stay up when it rolls but fall over when it stops? balancemotionspin Discover

let me guess Why does a ball on a string fly off the second you let go? motionforceinertia Discover

let me guess Why do two magnets sometimes snap together and sometimes shove apart? magnetsforcefields Discover

let me guess Why does a balloon get squished when you dive deep in a pool? pressurefloatingforce Discover

let me guess Does the shape of a piece of steel decide if it floats? floatingdensitypressurewater Discover

let me guess Why do tightrope walkers carry a long pole? balancemotionforce Discover

let me guess Why can a tiny kid lift a giant grown-up on a seesaw? leversbalanceforce Discover

let me guess Why do your shoes grip the floor but slip on ice? frictionmotionforce Discover

let me guess Is it harder to START a box sliding or to KEEP it sliding? frictionforcemotion Discover

let me guess What happens when a headphone plays a second sound? soundwavesinterference Discover

let me guess What does a microwave actually heat? waveswaterheat Discover

let me guess How does your phone know exactly where you are? spacesatellitesdistance Discover

let me guess Why does the internet get slow when everyone's online at once? networksinternetsharing Discover

let me guess How does a glass screen know exactly where your finger is? electricitysensestech Discover

let me guess WiFi, Bluetooth, infrared — why does a TV remote need to point, but your phone doesn't? wavessignalswireless Discover

let me guess Why is it so much harder to push a couch than to push a chair? motionforceinertia Discover

let me guess Do heavy things really fall faster than light ones? gravitymotionair Discover

let me guess Why is it hot in summer and cold in winter? spaceearthlightseasons Discover

let me guess Why do tiny things grow huge? growthmoneymathdoubling Discover

let me guess Why does ice float? waterdensitystates of matterice Discover

let me guess Why doesn't a whole town get sick at once? germsspreadhealth Discover

let me guess Why is the sky blue (and sunsets red)? lightcolorsky Discover

let me guess How does a song fly through the air into your radio? wavessoundphysics Discover

show me Why do some floors let you slide and some grab your feet? slipperysmooth and bumpysliding Discover

show me Shake oil and water hard — which one ends up on top? mixingoil and water Discover

show me Same cold, two feelings — which steals your warmth faster? warmthskinwater Discover

show me Why do I have two eyes? eyessensesdepth Discover

show me Why do magnets sometimes snap together and sometimes shove away? magnetspush and pull Discover

show me Why can you build a tall sandcastle with wet sand but not dry sand? sandwatersticking Discover

show me Why does sugar disappear in water but sand just sits there? dissolvingwatermixing Discover

show me Why does a rubber band snap back but squished clay just stays? materialsstretchysprings Discover

show me Why does a balloon stick to the wall after you rub it on your hair? electricitystaticphysics Discover

show me What happens when you drip a sour lemon into purple cabbage juice? acidscolorschemistry Discover

show me How can a little kid lift a great big grown-up on a seesaw? seesawbalancelevers Discover