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Project

Time, Causality, and Probability in Quantum Mechanics: Assessing Retrocausal Explanations in Light of Recent Experiments

Ingrained in our scientific mindset is the temporal arrow of causality — the idea that causation is time-asymmetric such that causes precede their effects temporally. In recent years, however, due in large part to the puzzles of quantum mechanics, scientists as renowned as John Wheeler, George Ellis and Yakir Aharonov have toyed with the idea that causality might be a two-headed arrow, and that choices made now might influence what has already happened. The aim of this project is to gauge the potential for such a retrocausal reformulation of quantum mechanics and to tease out the profound implications it would have for the nature of reality. Backward causation has been invoked to restore locality and determinism in quantum mechanics and to obtain a temporally symmetric theory.

Retrocausality also figures prominently in the recently proposed quantum theories of closed timelike curves. The aim of such theories is to provide a quantum mechanical model of time travel to the past where a particle may interact with an earlier version of itself. Last year, this form of time travel at the level of single particles was demonstrated in experiments. It is time to investigate how nature prevents paradoxical results as a result of influencing the past in this way.

Date:1 Jan 2016 →  31 Dec 2019
Keywords:Recent Experiments, Retrocausal Explanations, Quantum Mechanics, Probability, Causality, Time
Disciplines:Other engineering and technology