A wave source and two equidistant detectors are at rest in reference frame S', which moves with constant velocity v in frame S, along the common axis X. Clocks are synchronized so that at t = t' = 0 the origins of coordinates coincide: O = O'. At the same time a wave front quits the source and is eventually detected. We consider two cases:
| By choosing/setting | you may |
| S system / S' system | select the reference frame in which source and detectors move with velocity v / are at rest |
| Light / Sound | choose the special relativistic / Galilean case |
| v/c | set the dimensionless velocity: the Lorentz factor γ is automatically set (to 1 in the Galilean case) |
| ∆t | set the animation step length |
| Events | choose whether to stop when a door is closed or removed |
| Minkowski | select whether to show Minkowski's diagram |
| Show simultaneous | choose whether to show the events simultaneous with detections |
| Go | start the simulation from the emission time |
| Stop | stop the simulation |
| Continue | continue a simulation stopped at an event |
| Reset | recover all initial settings |