Verified instrument · Tier 1 · 2D

Boosted Minkowski

Drag the boost and watch simultaneity tilt. Worldlines, light cones, the twin trip, and the barn–pole squeeze — with every spacetime interval invariant to 12 decimal places, verified on every commit.

light raylight raysimultaneous in the lab frameembankment observertrain observer (β = 0.5)

What to notice

  1. Drag the boost slider: the dashed simultaneity line tilts. Two events simultaneous in one frame are not simultaneous in another.
  2. Switch to Twin paradox and boost hard: the worldlines shear, but the τ readouts never move — proper time is a Lorentz invariant.
  3. The light-cone diagonals never tilt at any boost: the speed of light is the same in every frame.
  4. Barn & pole: the two red coincidence dots share a horizontal line (same instant) only in the barn frame.

What "verified" means here

This instrument's physics kernel is covered by assertion classes V3, V5, V6 run on every commit — and its aha-fact is itself a named test:

⚑ Simultaneity is frame-dependent — yet every observer computes the same proper time along each worldline. Boost the diagram: τ never changes, and the twin “paradox” dissolves.