All Field Notes

Mathematics

Field Note

Finite Moves, Infinite Space

Game theory, discrete choices, and the larger spaces those choices create.

A game begins by becoming finite

To study a game, we name the players, the available moves, the information each player can see, and the outcomes they care about. The world is continuous and unruly; the model becomes useful by drawing a boundary.

That boundary is not a defect. A finite representation lets us derive something precise. But the precision belongs to the model, not automatically to the world.

Between rational and real

I like the strange intimacy between discrete moves and infinite spaces. A sequence of rational choices may approach a point it never contains. A small rule can generate an enormous state space. An algebraic structure becomes most expressive through the operations it permits and forbids.

Engineering works the same way. Every interface declares a game. Every evaluation function chooses which outcomes become visible.

The unresolved edge

When a system optimizes perfectly inside the game we gave it, how do we remain attentive to the world the game left out?