Chapter 1

Expository Articles

1.1. Quantum mechanics and Tomb Raider

Quantum mechanics has a number of weird consequences, but in this article

I will focus on three (inter-related) ones:

• Objects can behave both like particles (with definite position and

a continuum of states) and waves (with indefinite position and (in

confined situations) quantised states).

• The equations that govern quantum mechanics are deterministic,

but the standard interpretation of the solutions (the Copenhagen

interpretation) of these equations is probabilistic.

• If instead one applies the laws of quantum mechanics literally at the

macroscopic scale (via the relative state interpretation, more pop-

ularly known as the many worlds intepretation), then the universe

itself must split into the superposition of many distinct “worlds”.

What I will attempt to do here is to use the familiar concept of a com-

puter game as a classical conceptual model with which to capture these

non-classical phenomena. The exact choice of game is not terribly impor-

tant, but let us pick Tomb Raider—a popular game from about ten years

ago, in which the heroine, Lara Croft, explores various tombs and dungeons,

solving puzzles and dodging traps, in order to achieve some objective. It is

quite common for Lara to die in the game, for instance by failing to evade

one of the traps. (I should warn that this analogy will be rather violent on

certain computer-generated characters.)

The thing about such games is that there is an “internal universe”, in

which Lara interacts with other game elements, and occasionally is killed

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http://dx.doi.org/10.1090/mbk/059/01