Special Relativity Visualizer
This visualizer puts you in the cockpit of a ship that can approach the speed of light and shows what special relativity predicts you would actually see. Drag the velocity toward c and the scene responds with three linked effects: moving rulers shrink along the direction of travel (Lorentz contraction), a moving clock ticks slow (time dilation), and the light of the stars ahead blue-shifts and bunches toward a bright point while the stars behind red-shift and thin out (relativistic aberration and the Doppler shift). A lattice of rods and clocks makes the geometric distortions concrete, and a readout tracks the Lorentz factor γ so you can compare your clock with a stationary one.
Runs 100% in your browser — simulations are computed locally on your device.
Read the full guide to this tool
Notes
- The Lorentz factor γ = 1/√(1 − v²/c²) governs everything: at 0.87c, γ = 2, so lengths halve and clocks run at half speed; at 0.99c, γ ≈ 7, and the effects become extreme.
- Aberration sweeps the apparent positions of stars toward your direction of motion, so at high speed the sky ahead crowds into a small, bright, blue-shifted circle while the space behind you goes dark and red — the "relativistic headlight" effect.
- Time dilation is symmetric and real: each observer sees the other’s clock run slow. The famous twin "paradox" is resolved only because the travelling twin accelerates to turn around, breaking the symmetry.
- Runs 100% in your browser — simulations are computed locally on your device.
Related tools
Buoyancy Tank
Drop blocks of different density into water and watch Archimedes decide what floats, sinks or hovers.
Double Pendulum
Swing a chaotic double pendulum and split it into a rainbow swarm to watch nearby starts diverge.
Falling-Sand Playground
Paint sand, water, oil, fire and more and watch them pour, settle, burn and react pixel by pixel.
Fluid Flow Simulator
Stir glowing dye through a real-time GPU fluid simulation.
Galaxy Collision Simulator
Smash two spiral galaxies together and watch tidal tails and bridges form.
Hear the Shape of a Drum
Draw any drum and hear its true vibration modes — then meet two different drums that sound exactly the same.