The Xerographic Distribution: Scientific Reasoning in a Large Universe

TL;DR

The paper introduces the concept of the xerographic distribution, a probabilistic framework for making predictions about our location in a large universe, combining theory and assumptions to enable testable predictions.

Contribution

It formalizes the xerographic distribution as a key component for scientific reasoning in large universes, illustrated through a toy model.

Findings

The xerographic distribution allows predictions in a large universe context.

Combining theory with the xerographic distribution yields testable hypotheses.

The approach is demonstrated with a classical deterministic universe model.

Abstract

As observers of the universe we are physical systems within it. If the universe is very large in space and/or time, the probability becomes significant that the data on which we base predictions is replicated at other locations in spacetime. Predictions of our future observations therefore require an assumed probability distribution---the xerographic distribution---for our location among the possible ones. It is the combination of basic theory plus the xerographic distribution that can be predictive and testable by further observations. This is illustrated by examining a toy model of a classical deterministic universe with a fixed flat metric.