  We propose a method for computing the Kolmogorov-Sinai (KS) entropy of
chaotic systems. In this method, the KS entropy is expressed as a statistical
average over the canonical ensemble for a Hamiltonian with many ground states.
This Hamiltonian is constructed directly from an evolution equation that
exhibits chaotic dynamics. As an example, we compute the KS entropy for a
chaotic repeller by evaluating the thermodynamic entropy of a system with many
ground states.
