Accommodating Retrocausality with Free Will

TL;DR

This paper explores how retrocausal models in quantum mechanics can coexist with free will by analyzing causal loops and the role of quantum indeterminism in preserving causality.

Contribution

It introduces a novel analysis of causal loops involving opposing thermodynamic arrows and demonstrates how free will remains compatible with retrocausality through quantum masking.

Findings

Causal loops are avoided by destruction of the forecaster's past when predictions are revealed.

Quantum indeterminism masks future information, preserving causality.

Future events can be anticipated without violating free will or causing paradoxes.

Abstract

Retrocausal models of QM add further weight to the conflict between causality and the possible existence of free will. We analyze a simple closed causal loop ensuing from the interaction between two systems with opposing thermodynamic time arrows, such that each system can forecast future events for the other. The loop is avoided by the fact that the choice to abort an event thus forecasted leads to the destruction of the forecaster's past. Physical law therefore enables prophecy of future events only as long as this prophecy is not revealed to a free agent who can otherwise render it false. This resolution is demonstrated on an earlier finding derived from the Two-State-Vector Formalism (TSVF), where a weak measurement's outcome anticipates a future choice, yet this anticipation becomes apparent only after the choice has been actually made. To quantify this assertion, "weak information" is described in terms of Fisher information. We conclude that an already existing future does not exclude free will nor invoke causal paradoxes. On the quantum level, particles can be thought of as weakly interacting according to their past and future states, but causality remains intact as long as the future is masked by quantum indeterminism.