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.
Forces & motion
Interactions between parts can change motion and transmit turning forces.
Background on this ideaInteractive 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 explorationSpace & AstronomyRockets and propulsion
How can a rocket move when there is no air to push against?
Open a generic engine, follow what it carries and keep every bit of expelled mass in the story. Change who measures the motion, balance the thrust terms and discover what staging actually changes.
Interactive explorationSpace & AstronomyOrbits, satellites and gravity
How can falling keep a spacecraft above the ground?
Draw a velocity arrow, predict a path and compare two spacecraft on one clock. Follow a real NASA Earth map, inspect the next moment of free fall and discover why speed alone cannot make a circle.
Interactive explorationCities & TransportBridges, loads and structural strength
How does a bridge carry a moving load?
Move a load across an inspectable steel truss. Lift its deck, catch a diagonal changing from push to pull, repair a missing restraint and follow forces all the way to the supports.
Interactive explorationCities & TransportAirplane wings and lift
How can a wing turn moving air into lift?
Run a virtual wind-tunnel test. Tilt a symmetric airfoil, probe both surfaces, and build the whole lift force from pressure around the wing.
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.
A small distance.
A big internal pull.Explore the elbow’s leverage
Interactive explorationA big internal pull.Explore the elbow’s leverage
Body & HealthMuscles, joints and movement
Why can holding a small weight need a big muscle force?
Move a load closer to an elbow on a transparent teaching arm. See the force change, then explore how muscles can work without visible movement.
Interactive explorationPhysics, Light & SoundFloating, sinking and buoyancy
How can a heavy ship float?
Load a tiny barge and watch its waterline rise along the hull. Then lower a block through a tank to connect water pressure with buoyancy.