Maxwell's demon

Từ điển WordNet v3.1 - WordNet Dictionary

noun

an imaginary creature that controls a small hole in a partition that divides a chamber filled with gas into two parts and allows fast molecules to move in one direction and slow molecules to move in the other direction through the hole;
this would result in one part of the container becoming warmer and the other cooler, thus decreasing entropy and violating the second law of thermodynamics
• Instance Hypernyms:
imaginary being, imaginary creature