Physica

A growing lab of 67 hands-on physics experiments across the great branches of physics. Pick one below — launch it, tune the numbers, and watch the laws of nature play out in real time. You can also search all 67 experiments. Everything is free, and nothing needs to be installed.

Mechanical

• Projectile Motion — a body in free flight under gravity
• Newton's First Law — inertia until a net force acts
• Newton's Second Law — force, mass and acceleration
• Newton's Third Law — equal and opposite force pairs
• Atwood Machine — two masses over a pulley
• Double Pendulum — order giving way to chaos
• Standing Waves on a String — harmonics on a fixed string
• Projectile with Air Drag — a parabola bent by air resistance
• Doppler Effect — why a passing siren drops in pitch
• Beats — two close notes pulsing together
• Pendulum — period, amplitude and damping
• Mass on a Spring — simple harmonic motion
• Conservation of Energy — trading height for speed
• Circular Motion & Centripetal Force — the inward force of a turn
• Rolling Without Slipping — which shape wins down the ramp
• Angular Momentum — the figure-skater effect
• Orbital Mechanics — conic-section orbits around a star
• Gravitation: Force & Potential Energy — two masses pulling together
• Kepler's Three Laws — how the planets move
• Collisions — elastic and inelastic impacts
• Torque & Levers — balancing force times distance
• Driven Oscillator & Resonance — small pushes building huge swings
• Friction on an Incline — holding until the critical angle
• Center of Mass — the point that sails straight on

Thermal

• Kinetic Theory of Gases — temperature and pressure from collisions
• Heat Conduction — heat flowing hot to cold
• Heat Engine & Carnot Cycle — the ultimate limit on efficiency
• Entropy & Diffusion — two gases mixing, entropy climbing
• First Law of Thermodynamics — ΔU = Q − W
• Maxwell–Boltzmann Distribution — the bell curve of molecular speeds
• Gas Laws — pressure, volume, temperature, amount
• Blackbody Radiation — why hotter glows bluer
• Phase Changes & Latent Heat — energy that melts instead of warms

Electromagnetism

• Coulomb's Law & Field Lines — charges and the fields between them
• Charge in a Magnetic Field — a sideways push into a circle
• Circuit Builder — batteries, resistors and current
• Electromagnetic Waves — electric and magnetic fields in step
• Electromagnetic Induction — a changing flux makes current
• RLC Circuit & Resonance — one frequency lets current through
• RC Charging — a capacitor filling exponentially
• Motor & Generator — the same machine run both ways
• Capacitor & Dielectrics — storing energy between plates
• Transformer — turns ratio steps voltage up or down
• LC Oscillator — energy sloshing field to field

Optical

• Reflection of Light — angle in equals angle out
• Refraction & Snell's Law — light bending between materials
• Mirror Ray Diagrams — images from a curved mirror
• Lens Ray Diagrams — tracing rays through a thin lens
• Double-Slit Interference — bright and dark bands of light
• Single-Slit Diffraction — waves spreading through a gap
• Dispersion & the Spectrum — a prism fanning white light
• Polarization & Malus's Law — filters dimming light by angle
• Diffraction Grating — many slits sharpening the fringes
• Thin-Film Interference — the colours of a soap film

Modern

• Photoelectric Effect — photons knocking electrons free
• Bohr Model of the Atom — quantum jumps and their colours
• Special Relativity — moving clocks tick slower
• Quantum Well — a particle's discrete energies
• Black Hole — where not even light escapes
• Radioactive Decay & Half-Life — random decay, smooth curve

Fluid

• Buoyancy & Archimedes' Principle — what floats and what sinks
• Bernoulli's Principle — faster flow, lower pressure
• Pascal's Principle — a small piston lifting a great weight
• Viscosity & Turbulence — laminar sheets breaking into a wake
• Stokes Drag & Terminal Velocity — drag rising to cancel gravity
• Poiseuille Flow — fastest down the middle of a pipe
• Surface Tension & Capillary Rise — a liquid skin climbing a tube