The language of “collapse” used throughout this book is borrowed from quantum mechanics. This chapter explains the borrowing, and its limits.
The Physics, Briefly
In quantum mechanics, the state of a system before measurement is described by a wave function, which can represent a combination, or superposition, of several possible outcomes at once. When a measurement is made, one definite outcome is observed. Physicists commonly describe this as the wave function “collapsing” to one result.
What collapse really is, and whether anything physically collapses at all, is one of the great open questions of physics. Different interpretations answer it very differently. This book does not take a side on that debate and does not depend on any one answer to it.
A few of the main options, to show how unsettled this is. In the Copenhagen family of views, collapse is a real, if poorly understood, transition that happens on measurement. In Hugh Everett’s many-worlds interpretation (1957), nothing collapses; every outcome occurs, each in its own branch. In pilot-wave theory (de Broglie and Bohm), particles always have definite positions and the wave function guides them, so collapse is only apparent. Objective-collapse theories, such as GRW (Ghirardi, Rimini, and Weber), modify the equations so that collapse happens spontaneously. Separately, the phenomenon of decoherence explains why superpositions of large objects become practically invisible, though most physicists agree it does not, by itself, pick out a single outcome. The rules for computing probabilities, the Born rule, are the same across all of these; they disagree about what is going on underneath.
The Analogy
What the language offers is a picture. Before a choice is made, there are many genuinely possible histories. When an agent chooses, one of them becomes actual and the others do not. That is something like a collapse: a field of real possibility resolving into one definite fact.
On this picture, God knows the entire field of possibilities, completely, before any of it resolves. Agents, by choosing, determine how it resolves.
Two Kinds of Collapse
The analogy also helps name the difference at the heart of this model:
- A decree collapses an outcome. When God declares that something will happen, every possible history that misses it is removed from the field.
- A choice collapses a person’s own path. When an agent chooses, one of the remaining possibilities in their own life becomes actual. Only the agent can do that.
God does the first. He never does the second on anyone’s behalf. That is why this book can say both that God’s prophecies are certain and that God never overrides a person’s agency. The prophecy is collapsed. The people are not.
The Limits of the Analogy
This is an analogy, not a claim that the gospel is quantum mechanics. It does not say that human choice is a quantum event, or that physics proves anything about God. Its value is that it offers a precise picture of something otherwise hard to say: that a range of real possibilities can resolve into one actuality, and that some features of the result can be settled while others remain genuinely open.
Three specific points of disanalogy are worth naming. First, quantum outcomes are, as far as standard physics can tell, random: governed by probabilities, not by anyone’s choice. Free agency in this model is not randomness; it is a person deciding. Second, a decree that fixes an outcome has no clean quantum counterpart. The closest, loosely, is the way a later measurement result constrains which earlier descriptions are consistent with it, an idea developed in the two-state vector formalism discussed in “Open Questions.” Third, the many-worlds interpretation, where every possibility is realized, is the opposite of this model, in which only one history becomes actual and the rest remain forever merely possible. If you hold the many-worlds view of physics, the analogy here should be read as a picture only.
Used carefully, though, the vocabulary is helpful. It reminds us that “possible” and “actual” are not the same, that knowledge of a full range of possibilities is a coherent idea, and that a whole can have definite features while its parts are still open.