Entropy

Entropy.
A measure of randomness, a parameter of disorder.
Energy broken down in irretrievable heat.
What might appear to be chaos, even decay,
is really a system’s way of smoothing out differences — its search for equilibrium.
Uncorrelated parts interact,
find their connections in an evolving system
so, from one perspective, entropy is a clock
charting the irreversible.

NUMB3RS Episode 511: Arrow of Time–Wolfram Research Math Notes