Schroedingers-Hat/jsphys — comment on commit e0ba557fd7574aae5cbf29a0308bb2f1a1b848b7
File: relativity/js/fourEvent.js line 47
By Schroedingers-Hat:

This can be a flag that gets set/unset when travelling past the event.
To avoid set-unset-set-unset type nonsense the forward and backward light cones could be used.
ie. when it enters the past light cone, it has happened, and will trigger playback/caption change

There will need to be some monitor for different captions where each event can say 'i happened x seconds ago' or 'i haven't happened'. Then the latest caption for which the corresponding fourEvent has happened will display.

For managing audio the event could play the track, or if audio is already playing, pause the demo. Upon pausing, the track is queued to be played when the demo is un-paused.