The Philosophy of Time Travel · Chapter 4
The Artifact and the Living
The Artifact is the metal object that appears out of nowhere at the start of a Tangent Universe. In the film it is the jet engine that lands in Donnie's bedroom on October 2 — the engine nobody can trace to a plane, because the plane it belongs to will not lose it for another 28 days.
When a Tangent Universe occurs, those living nearest to the Vortex will find themselves at the epicenter of a dangerous new world.
Artifacts provide the first sign that a Tangent Universe has occurred.
If an Artifact occurs, the Living will retrieve it with great interest and curiosity. Artifacts are formed from metal, such as an Arrowhead from an ancient Mayan civilization, or a Metal Sword from Medieval Europe.
Artifacts returned to the Primary Universe are often linked to religious Iconography, as their appearance on Earth seems to defy logical explanation.
Divine intervention is deemed the only logical conclusion for the appearance of the Artifact.
In the film
The chapter accounts for the film's central mystery: the FAA cannot identify the jet engine because, in the Primary Universe, it has not fallen yet. It is torn from the plane carrying Rose and Samantha Darko in the last minutes of the Tangent Universe and sent back through the Time Portal to October 2. The Artifact is therefore both the first sign of the Tangent Universe and the object whose return ends it.
Sparrow's examples - the Mayan arrowhead, the medieval sword - suggest that Tangent Universes have occurred before and that their Artifacts were recorded as relics or miracles. The FAA agents who cannot trace the engine are the film's version of that bafflement.
"Those living nearest to the Vortex" is why the Darko household and its neighbours become the Manipulated: the Vortex opens directly above Donnie's house.
Where this chapter happens on screen.