Spacetime Lab
Spacetime Lab is an interactive laboratory for special relativity: drag events and observers on a Minkowski diagram and watch the geometry of spacetime respond in real time, with every number on screen produced by an actual physics engine rather than written into the interface.
Spacetime Lab — Change the observer. Change the constants. Change the universe.
Not a simulator with three sliders — a workbench where direct manipulation, instant numeric feedback and the geometry are the same act. Every value on screen — intervals, the Lorentz factor, time dilation — is produced by a real physics engine, so the interface can never drift out of step with the mathematics.
What you can do:
- Manipulate spacetime directly: drag events and worldlines on the Minkowski diagram, with a live read-out of x, t, Δs² and causal classification.
- Change reference frames: every observer offers "View from this observer," animated through rapidity.
- Watch invariance rather than being told about it: Δt and Δx change, Δs² doesn't.
- Change the speed of light in an Experimental Universe and watch β and γ respond.
- Explore the limit cases: the Lorentz transformation collapsing into the Galilean one, γ diverging as β → 1.
- Run 13 preloaded experiments: light clock, time dilation, length contraction, relativity of simultaneity, twin paradox, barn and pole, velocity addition, Bell's spaceships, causality, photon chase, and the limit cases.
- See the light cone in 3D (2+1 dimensions), where a boosted plane of simultaneity visibly cuts an ellipse out of it.
- Actually go somewhere: pick a real destination — Mars, Vega, Sgr A*, Andromeda, TON 618 — and a way of getting there, with Earth time, ship time, peak γ and Doppler shift all computed live.
- Bilingual English/Italian interface, with contextual explanations on every panel.
Built with React, Three.js and a purpose-built physics engine, fully tested (270+ automated tests).