Saturday, June 19, 2010

Quantum Poker in Star Wars

Hardcore Star Wars aficionados may be familiar with Sabacc, the fictional poker-like card game popular with lowly spice smugglers and interplanetary tycoons alike.  Without delving too much into the nerdy arcana, players receive cards grouped by value (1-15 plus 16 face cards) and suit (Coins, Flasks, Sabres, Staves).  There are several rounds of betting, the pot going to the player with the strongest hand based on a specific hierarchy.  The main feature of the game is the shifting nature of the cards: while in a player's hand, every card may randomly change its value and suit based on a predetermined probability distribution.  During each round of betting, players have the option to place cards face down on the table.  This action locks in the card's value and suit, preventing further shifts.

So why is this relevant?  Sabacc provides a perfect real-world analogy for the concept of quantum superposition, or the condition of an object existing in several mutually-exclusive states simultaneously.  Emerging from modern particle physics, quantum superposition is perhaps best known by the famous thought experiment Schrödinger's Cat.  A key feature of quantum superposition is its collapse: whenever the superpositioned object is measured, its strange quantum condition ends and a single observable state emerges.  Returning to the Sabacc analogy, we can view a player as holding cards that exist in a probabilistic superposition.  Due to the random shifting, each card possesses not one value, but rather a probability distribution of every possible value.  Placing a card on the table collapses this distribution into a single value and suit.

The concept of quantum superposition, once relegated to the netherworld of quantum mechanics, is seeing an explosion of applications.  Most interesting is the fledgling field of quantum game theory, which allows for the quantum superposition of strategies by players, in addition to regular pure and mixed strategies.  For more information about quantum superposition and its exciting new applications, check out episode three of the Math For Primates podcast.

1 comment :

  1. You are so smart and well spoken! You can even make a nerdy Star Wars game sound awesome. Major props. (PS. Bring the cards to Iceland; I want to learn to play.)

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