i times natural log of p sub i.
For one type of object, this quantity is proportional to the cube of the speed of light and one-fourth the
 area of the object. For an ideal gas, this property approaches negative infinity as temperature approaches
 absolute zero, as a consequence of the natural logarithm term in the Sackur-Tetrode equation. In
 information theory, it is proportional to the sum over all possible values of a random variable of the
 quantity p sub i times natural log of p sub i. That relation is derived from a similar equation, stating it is
 proportional to the natural log of the number of microstates of a system, elucidated by Ludwig Boltzmann.
 For 10 points, name this ever-increasing quantity that measures the amount of disorder in a system.
For one type of object, this quantity is proportional to the cube of the speed of light and one-fourth the
 area of the object.
{entropy} [prompt on {S}]