The Overcoat, by Nikolai Gogol.
From this thread What Stephen ‘Mathematica’ Wolfram’s been up to [Robot Wisdom], which starts with a rant about an interview with Stephan Wolfram, who wrote the legendary program Mathematica, I got to The Finite Nature Hypothesis of Edward Fredkin.
Apparently, Fredkin’s theory is that nature is finite, and can be modelled at the most basic level as a cellular automata. In simpler terms, nature is a computer program.
What he’s saying, quite simply, is that we may be living in The Matrix.