We all know it’s impossible to predict the future, but not many people stop to think about why. Free choice issues aside, it’s not easy. After all, you can use Isaac Newton’s laws of motion to calculate what an object will do if you know its starting trajectory and the forces acting on it. The French thinker Pierre-Simon Laplace once imagined a being armed with these laws and a great deal of information, saying, “For such an intellect, nothing is uncertain, and the future is as clear to the eye as the past.” It will exist before,” he wrote.
The reason the world still unfolds in unexpected cascades is because there is a gap between what equations can predict in theory and what can be calculated in practice. The limitations of our technology, the speed of our computers, and the incredible complexity of nature all mean that there are things we can never really know.
This article is part of a special series on the limits of knowledge.
One problem is that what we want to study may consist of many interacting objects. So while the course of flying football is predictable without any problems,…