Today's post, Configurations and Amplitude was originally published on 10 April 2008. A summary (taken from the LW wiki):

A preliminary glimpse at the stuff reality is made of. The classic split-photon experiment with half-silvered mirrors. Alternative pathways the photon can take, can cancel each other out. The mysterious measuring tool that tells us the relative squared moduli.

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This post is part of the Rerunning the Sequences series, where we'll be going through Eliezer Yudkowsky's old posts in order so that people who are interested can (re-)read and discuss them. The previous post was Quantum Explanations, and you can use the sequence_reruns tag or rss feed to follow the rest of the series.

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