Interactive exploration
Machines & MotionGears and gear ratios
How do gears trade speed for turning force?
Turn once. Count what happens. Discover gear ratios, real-world uses, and why different jobs need different gears.
Machines & Motion
Follow a force. Take apart a mechanism. Make something move.
Try a question:
10 matching explorations
Interactive exploration
Machines & MotionHydraulic brakes
How does a little lever stop a spinning wheel?
Squeeze a hydraulic brake. See inside the caliper, change piston sizes, and discover how pressure becomes force.
Interactive explorationMachines & MotionGenerators, electromagnetic induction and alternators
Can turning a handle make a light turn on?
Turn a tabletop generator, unplug its lamp, and replay the same motion. Follow the voltage, the pushback and every joule to discover where electrical energy comes from.
Interactive explorationMachines & MotionRobot arms, inverse kinematics and tool position
Can a robot turn its gripper without moving its center?
Tilt a real robot model while keeping its gripper center on a target. Compare two routes between the same poses, discover what stops a reach, and build a paper arm with two ways to touch one point.
Interactive explorationMachines & MotionBall bearings, skateboard wheels and rolling friction
What helps a skateboard wheel keep spinning?
Make a wheel see-through, follow a marked ball and test which motions can roll. Then discover why a longer spin does not always mean less friction.
Interactive explorationMachines & MotionNoise-canceling headphones, destructive interference and ANC
How can noise-canceling headphones make things quieter?
Open a headphone, line up two pressure changes, then keep your setting while the sound changes. Discover why timing, microphones and location matter—and inspect a real measured acoustic path.
Interactive explorationMachines & MotionCar differentials and transmissions
How do driven wheels take different paths around a corner?
Follow a transparent car around a bend, open its rear axle, and discover how a differential shares motion, torque and a low-grip limit.
Interactive exploration
Machines & MotionElectric motors
How does electricity make a motor spin?
Power a motor. Reverse its direction. Add a load and watch speed, current and turning force find a new balance.
Interactive explorationMachines & MotionFour-stroke engines
How does a piston turn fuel into motion?
Open a detailed engine, turn its crank, and take the assembly apart. Follow four different jobs hidden inside two very similar-looking turns.
Interactive explorationMachines & MotionLevers, pulleys and lifting
How can a small pull lift a heavy load?
Rerig a dock crane. Pull the same length of rope, watch the crate rise, and see what you trade for an easier lift.
Help choose future lessons
Optional. These phrases are saved privately for up to 30 days and included in a weekly report to our team. We do not attach your account or send the phrases to Mixpanel. Please leave out personal details. About search privacy
Every exploration includes its sources, model assumptions, and scientific review status. See the review process.
Where will curiosity take us?
Body & Health12Brain & Senses9Cells, Life & Evolution6Machines & Motion10Electricity & Energy5Computers, Networks & AI12Cities & Transport3Chemistry & Materials4Earth, Weather & Climate8Nature, Ecosystems & Food2Space & Astronomy5Physics, Light & Sound4Math, Probability & Systems1Everyday Technology8Scientific Thinking & Big Ideas1