Make it move

Start with a turn or a pull. Connect gears, engine timing, crane rigging and the surprising forces inside an arm.

Interactive exploration

Machines & 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.

3D model & experimentsExplore at your own pace

#differential#gears#cars#torque

Interactive exploration

Cities & 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.

3D model & experimentsExplore at your own pace

#flight#wings#airflow#lift

Interactive exploration

Machines & 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.

3D working model & experimentExplore at your own pace

#engines#pistons#crankshaft#combustion

Interactive exploration

Machines & 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.

3D working model & experimentExplore at your own pace

#pulleys#levers#lifting#work

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.

3D mechanismExplore at your own pace

#gears#bicycle#torque#mechanical-advantage

A small distance.
A big internal pull.Explore the elbow’s leverage

Interactive exploration

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.

3D working model & experimentExplore at your own pace

#muscles#joints#biomechanics#tendons

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.

3D cutaway & experimentExplore at your own pace

#hydraulics#pressure#bicycle#friction

Take these steps at your own pace. Your place is not saved as account progress or scored.