The Quantum Many-Worlds Interpretation, Simply Told

TL;DR

This paper explores the many-worlds interpretation of quantum mechanics by modeling a bolometer detector in an atom interferometer, demonstrating how it aligns with observed outcomes without action at a distance.

Contribution

It provides a simplified model illustrating how MWI accounts for measurement outcomes consistent with experiments, emphasizing its non-action-at-a-distance nature.

Findings

MWI predicts all outcomes occur, but observers see only one per measurement.

The model shows MWI's predictions match experimental results.

MWI does not imply action at a distance.

Abstract

The many-worlds interpretation (MWI) of quantum mechanics poses a simple question. What would reality look like if everything evolved in time according to the same quantum equations? There is an attractive consistency to treating microscopic objects, measuring devices, and observers all on the same footing, but do the predictions match our observations? Here, we build a model for a bolometer detector making a which-path measurement in an atom interferometer. We discuss the MWI claim that, while both measurement outcomes occur in each experimental iteration, an observer will experience only one outcome or the other, with a probability consistent with experiment. Finally, we discuss how MWI does not have action at a distance. This article is written to be accessible to anyone with an undergraduate course in quantum mechanics.