Entropy, the amount of molecular disorder, is produced in several systems but cannot be measured directly. A new equation sheds new light on how entropy is produced on a very short time scale in laser ...

Exactly 200 years ago, a French engineer introduced an idea that would quantify the universe’s inexorable slide into decay. But entropy, as it’s currently understood, is less a fact about the world ...

Entropy also increases in initially ordered quantum systems until it reaches a final state of disorder. Entropy and the direction of time Equating 'entropy' with 'disorder' is not entirely correct.