From the point of view of an observer over a tunnel, a train of longer
proper length can be trapped inside the tunnel, as a consequence of the
Lorentz-FitzGerald contraction, provided the train's velocity is high
enough. This can be simulated in this animation, where
| by choosing/setting | you may |
| Train / Tunnel frame | select the point of view of the observer moving with the train or the tunnel |
| v/c | set the train/tunnel velocity (the Lorentz factor γ is automatically set) |
| L | choose the tunnel length (the unit length is that of train) |
| ∆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 (in the other frame) with door opening/removing |
| Go | start the simulation from initial time |
| Continue | continue a simulation stopped at an event |
| Stop | stop the simulation |
| Reset | recover all initial settings |