In his A Philosophical Essay on Probabilities (1814), Pierre-Simon Laplace describes a perfectly deterministic universe:
We ought to regard the present state of the universe as the effect of its antecedent state and as the cause of the state that is to follow. An intelligence knowing all the forces acting in nature at a given instant, as well as the momentary positions of all things in the universe, would be able to comprehend in one single formula the motions of the largest bodies as well as the lightest atoms in the world, provided that its intellect were sufficiently powerful to subject all data to analysis; to it nothing would be uncertain, the future as well as the past would be present to its eyes.1
That all-seeing intelligence has since been nicknamed “Laplace’s demon.” In recent decades, developments in areas such as chaos, complexity, and quantum mechanics suggest that ours is not Laplace’s universe, at least not from top to bottom—our universe, according to some, has randomness built in, is often messy and unpredictable.
But suppose you’re not convinced by those developments and still think the world a place of strictly regulated cause-and-effect. Perhaps I can convince you that at least one other feature of the universe would be unfriendly to the demon: human consciousness.2
Imagine Laplace’s demon—”LD” for short—is a recently built super computer engaged in the analysis Laplace describes. One day, an LD project researcher—let’s call her Shelly—has the idea that LD can predict her future. Using LD for such a thing would be frowned upon as unethical, but she figures she’ll give it a dabble just to see how her next few hours will go. Continue Reading