Glossary
Liquid Spears
The translucent, water-like tendrils Donnie sees extending from people's chests, showing the path each person is about to take. The name is Donnie's own: he tells Dr Thurman they are "like liquid" and come out of the chest "like spears".
Donnie first sees them at the family dinner table and follows his own to his father's closet, where the gun is kept. Describing them to Dr Thurman, he says they are "like liquid"; she asks whether they come out of his chest, and he answers "like spears" - which is where the name comes from. Sparrow's book never mentions them.
They are the film's visual for the conversation Donnie has with Professor Monnitoff about "God's channel": if everyone's path is fixed, one could see it in advance. The spears are made of water, tying them to the Fourth Dimensional Construct.
Defined in The Philosophy of Time Travel