"Exhalation" is the name of a short story by American author Ted Chiang. The story belongs to the genre of science fiction, and it discusses a race of mechanical beings. It won the 2009 Hugo Award for Best Short Story.
The story centers around a scientist, who realizes that clocks have begun to operate faster than usual. However, as they do not seem to be broken, the scientist hypothesizes that human brains are computing slower. He is able to test this theory through experimentation. The description of the experiment is meant to give rise to curiosity and excitement in the reader, and it also contributes to establishing this science fiction "universe" as something cohesive and possible.