How a giant magnet builds an image of the inside of you, step by step — from a single hydrogen nucleus to a finished medical image.

Satellite orbiting Earth with Newtonian gravity. Adjust mass, see velocity & force vectors.

All 8 planets with real sizes, distances, elliptical orbits & Kepler's laws.

The 5 points where Sun-Earth gravity balances rotation. Explore the effective-potential landscape and find the saddles and peaks.

U = mgh. Drop a ball on Earth, the Moon, Mars or Jupiter — watch potential energy convert to kinetic with E staying constant.

Newton's law F = GMm/r² in action. Release a test mass and watch it fall, orbit or escape depending on its initial speed.

Watch galaxies recede in every direction, turning red with distance. Click any galaxy to read its z and Hubble's law.

Push a box with a constant force over a distance. Watch W = F·d accumulate and turn directly into kinetic energy — the work-energy theorem in action.

A block slides down a ramp with friction. Watch U → KE + Q and read off the efficiency η = 1 − μ/tanθ — energy conservation with heat included.

A crane lifts a crate at constant speed. P = F·v in real time, W = mgh fills the energy bar. Crank the speed up — same work, more power, less time.

Newton's 2nd law (F = ma) with air drag. Adjust mass and engine force.

See how a force at angle θ decomposes into Fx = F·cosθ and Fy = F·sinθ. Tilt the angle and watch the components rebalance live.

Why is a = −∇U? Drop a particle onto a potential landscape and watch the force arrow emerge from the gradient.

Explore Archimedes' principle with an interactive 3D simulation. Adjust object density and watch it float, sink, or reach neutral buoyancy in real time.

U = R·I in a closed circuit. The resistor literally narrows as R grows, and more electrons stream through as current rises.

Drag wires between component pins to build a closed circuit. Series and parallel topologies emerge from how you connect things. Live readouts show equivalent resistance, branch currents and power per component.

Place and drag charges. See Coulomb force vectors, field lines & equipotential surfaces.

Spinning magnet induces EMF in a coil. Adjust windings and speed, see flux and voltage graphs.

Shine monochromatic light through a diffraction grating and watch d·sin θ = n·λ paint the maxima onto a screen. Tune λ, line density and screen distance to see the pattern fan out.

Watch wavefronts from N slits interfere in real time. Vary λ, slit count N and spacing d — see d·sinθ = n·λ produce the bright and dark fringes right in front of you.

Explore Snell's law interactively — adjust angle of incidence, refractive indices, and wavelength to see how light bends at an interface. Observe total internal reflection and Fresnel reflectance live.

Watch a cloud of atoms decay stochastically in real time. Each atom decays randomly — but together they follow N(t) = N₀·2^(−t/T½) to the letter. Tune T½ and N₀ and see statistical noise vanish at large N.

Fly a shuttle through the solar system. Full 3D with throttle, pitch, yaw & roll. Not real physics — just fun.